On 4/23/2013 7:57 PM, Gunner Asch wrote:
Fella brought over a gun part for a Marlin lever action..he was
missing a pin..so I made one up for him and installed it..and as I was
inspecting it..I noticed a rather serious crack starting to develop at
one end of the sintered metal part. I fixed it by using my tig torch
and silver bearing flux..I packed the crack full of the heavy green
flux and zapped it with the tig..sealed it up well enough and I put a
slight layer over the area of the crack. After polishing it up with a
fine wire wheel, it looked good. But...is it?

How well does this sort of thing work with sintered metal parts?

Should I warn the guy to buy a new Widget? (Marlin just closed their
doors...so parts may become hard to find)

Any suggestions for other similar fixs with sintered metal parts?

Gunner



Which part?

On 4/23/2013 9:12 PM, Gunner Asch wrote:
On Tue, 23 Apr 2013 08:41:46 -0500,
wrote:

On 4/23/2013 7:57 PM, Gunner Asch wrote:
Fella brought over a gun part for a Marlin lever action..he was
missing a pin..so I made one up for him and installed it..and as I was
inspecting it..I noticed a rather serious crack starting to develop at
one end of the sintered metal part. I fixed it by using my tig torch
and silver bearing flux..I packed the crack full of the heavy green
flux and zapped it with the tig..sealed it up well enough and I put a
slight layer over the area of the crack. After polishing it up with a
fine wire wheel, it looked good. But...is it?

How well does this sort of thing work with sintered metal parts?

Should I warn the guy to buy a new Widget? (Marlin just closed their
doors...so parts may become hard to find)

Any suggestions for other similar fixs with sintered metal parts?

Gunner



Which part?

http://marauder.homestead.com/files/Marlin94P.html

#8

Carrier Assembly




On this one, if it fails, it doesn't look like there is much chance of
a major catastrophe. The weapon may become inoperable, but shouldn't
explode, or set off a round by accident.
But that's just from looking at the parts drawing.

With that caveat, the owner decides....

Personally, I'd order a new one.

On 4/24/2013 12:48 AM, Gunner Asch wrote:
On Tue, 23 Apr 2013 08:41:46 -0500,
wrote:

On 4/23/2013 7:57 PM, Gunner Asch wrote:
Fella brought over a gun part for a Marlin lever action..he was
missing a pin..so I made one up for him and installed it..and as I was
inspecting it..I noticed a rather serious crack starting to develop at
one end of the sintered metal part. I fixed it by using my tig torch
and silver bearing flux..I packed the crack full of the heavy green
flux and zapped it with the tig..sealed it up well enough and I put a
slight layer over the area of the crack. After polishing it up with a
fine wire wheel, it looked good. But...is it?

How well does this sort of thing work with sintered metal parts?

Should I warn the guy to buy a new Widget? (Marlin just closed their
doors...so parts may become hard to find)

Any suggestions for other similar fixs with sintered metal parts?

Gunner



Which part?

Better link

http://www.urban-armory.com/diagrams/mar1894.gif

Part #8, 9, and 10 (and 11)

He was missing the #10 pin..and I turned, annealed, replaced it and
peened it into place gently.

Gunner



Why do I get the impression that the rifle has been overstressed?
Repeatedly.

Fella brought over a gun part for a Marlin lever action..he was
missing a pin..so I made one up for him and installed it..and as I was
inspecting it..I noticed a rather serious crack starting to develop at
one end of the sintered metal part. I fixed it by using my tig torch
and silver bearing flux..I packed the crack full of the heavy green
flux and zapped it with the tig..sealed it up well enough and I put a
slight layer over the area of the crack. After polishing it up with a
fine wire wheel, it looked good. But...is it?

How well does this sort of thing work with sintered metal parts?

Should I warn the guy to buy a new Widget? (Marlin just closed their
doors...so parts may become hard to find)

Any suggestions for other similar fixs with sintered metal parts?

Gunner

On Tue, 23 Apr 2013 08:41:46 -0500, Richard
wrote:

On 4/23/2013 7:57 PM, Gunner Asch wrote:
Fella brought over a gun part for a Marlin lever action..he was
missing a pin..so I made one up for him and installed it..and as I was
inspecting it..I noticed a rather serious crack starting to develop at
one end of the sintered metal part. I fixed it by using my tig torch
and silver bearing flux..I packed the crack full of the heavy green
flux and zapped it with the tig..sealed it up well enough and I put a
slight layer over the area of the crack. After polishing it up with a
fine wire wheel, it looked good. But...is it?

How well does this sort of thing work with sintered metal parts?

Should I warn the guy to buy a new Widget? (Marlin just closed their
doors...so parts may become hard to find)

Any suggestions for other similar fixs with sintered metal parts?

Gunner



Which part?

Get an expert involved. High-strength ferrous sintered parts often are
copper-infiltrated.

Don't weld that stuff unless you know what you're doing, especially if
it's a safety-related part.

--
Ed Huntress

On Tue, 23 Apr 2013 08:41:46 -0500, Richard
wrote:

On 4/23/2013 7:57 PM, Gunner Asch wrote:
Fella brought over a gun part for a Marlin lever action..he was
missing a pin..so I made one up for him and installed it..and as I was
inspecting it..I noticed a rather serious crack starting to develop at
one end of the sintered metal part. I fixed it by using my tig torch
and silver bearing flux..I packed the crack full of the heavy green
flux and zapped it with the tig..sealed it up well enough and I put a
slight layer over the area of the crack. After polishing it up with a
fine wire wheel, it looked good. But...is it?

How well does this sort of thing work with sintered metal parts?

Should I warn the guy to buy a new Widget? (Marlin just closed their
doors...so parts may become hard to find)

Any suggestions for other similar fixs with sintered metal parts?

Gunner



Which part?

http://marauder.homestead.com/files/Marlin94P.html

#8

Carrier Assembly

On Tue, 23 Apr 2013 08:41:46 -0500, Richard
wrote:

On 4/23/2013 7:57 PM, Gunner Asch wrote:
Fella brought over a gun part for a Marlin lever action..he was
missing a pin..so I made one up for him and installed it..and as I was
inspecting it..I noticed a rather serious crack starting to develop at
one end of the sintered metal part. I fixed it by using my tig torch
and silver bearing flux..I packed the crack full of the heavy green
flux and zapped it with the tig..sealed it up well enough and I put a
slight layer over the area of the crack. After polishing it up with a
fine wire wheel, it looked good. But...is it?

How well does this sort of thing work with sintered metal parts?

Should I warn the guy to buy a new Widget? (Marlin just closed their
doors...so parts may become hard to find)

Any suggestions for other similar fixs with sintered metal parts?

Gunner



Which part?

Better link

http://www.urban-armory.com/diagrams/mar1894.gif

Part #8, 9, and 10 (and 11)

He was missing the #10 pin..and I turned, annealed, replaced it and
peened it into place gently.

Gunner

On Tue, 23 Apr 2013 10:14:55 -0500, Richard
wrote:

On 4/23/2013 9:12 PM, Gunner Asch wrote:
On Tue, 23 Apr 2013 08:41:46 -0500,
wrote:

On 4/23/2013 7:57 PM, Gunner Asch wrote:
Fella brought over a gun part for a Marlin lever action..he was
missing a pin..so I made one up for him and installed it..and as I was
inspecting it..I noticed a rather serious crack starting to develop at
one end of the sintered metal part. I fixed it by using my tig torch
and silver bearing flux..I packed the crack full of the heavy green
flux and zapped it with the tig..sealed it up well enough and I put a
slight layer over the area of the crack. After polishing it up with a
fine wire wheel, it looked good. But...is it?

How well does this sort of thing work with sintered metal parts?

Should I warn the guy to buy a new Widget? (Marlin just closed their
doors...so parts may become hard to find)

Any suggestions for other similar fixs with sintered metal parts?

Gunner



Which part?

http://marauder.homestead.com/files/Marlin94P.html

#8

Carrier Assembly




On this one, if it fails, it doesn't look like there is much chance of
a major catastrophe. The weapon may become inoperable, but shouldn't
explode, or set off a round by accident.
But that's just from looking at the parts drawing.

With that caveat, the owner decides....

Personally, I'd order a new one.

Oh..its not..not a safety critical piece. Not in the slightest. Which
is why I silver soldered it..and then asked here.

I notice that Midway sells a later version of it for $50 or so.

So Ill warn the end user, but had been courious about the idea of
soldering sintered metal.

Gunner

On Tue, 23 Apr 2013 12:57:20 -0500, Richard
wrote:

On 4/24/2013 12:48 AM, Gunner Asch wrote:
On Tue, 23 Apr 2013 08:41:46 -0500,
wrote:

On 4/23/2013 7:57 PM, Gunner Asch wrote:
Fella brought over a gun part for a Marlin lever action..he was
missing a pin..so I made one up for him and installed it..and as I was
inspecting it..I noticed a rather serious crack starting to develop at
one end of the sintered metal part. I fixed it by using my tig torch
and silver bearing flux..I packed the crack full of the heavy green
flux and zapped it with the tig..sealed it up well enough and I put a
slight layer over the area of the crack. After polishing it up with a
fine wire wheel, it looked good. But...is it?

How well does this sort of thing work with sintered metal parts?

Should I warn the guy to buy a new Widget? (Marlin just closed their
doors...so parts may become hard to find)

Any suggestions for other similar fixs with sintered metal parts?

Gunner



Which part?

Better link

http://www.urban-armory.com/diagrams/mar1894.gif

Part #8, 9, and 10 (and 11)

He was missing the #10 pin..and I turned, annealed, replaced it and
peened it into place gently.

Gunner



Why do I get the impression that the rifle has been overstressed?
Repeatedly.


Its a lever action 357 Mag...I dought it could be overstressed very
much.

Sintered metal parts...dont have a sterling track record.....in some
cases. Particularly those that take "impact"/high loading

They work well enough for static loads...the Buck folder in my
pocket..the brass frame..is powdered metal sintering..but it never has
a sudden high stress loading.

A lot of motorcycle brake disks are sintered. But they dont get hit.


Gunner

On Apr 23, 12:57*pm, Richard wrote:
On 4/24/2013 12:48 AM, Gunner Asch wrote:









On Tue, 23 Apr 2013 08:41:46 -0500,
wrote:

On 4/23/2013 7:57 PM, Gunner Asch wrote:
Fella brought over a gun part for a Marlin lever action..he was
missing a pin..so I made one up for him and installed it..and as I was
inspecting it..I noticed a rather serious crack starting to develop at
one end of the sintered metal part. * I fixed it by using my tig torch
and silver bearing flux..I packed the crack full of the heavy green
flux and zapped it with the tig..sealed it up well enough and I put a
slight layer over the area of the crack. After polishing it up with a
fine wire wheel, it looked good. But...is it?

How well does this sort of thing work with sintered metal parts?

Should I warn the guy to buy a new Widget? (Marlin just closed their
doors...so parts may become hard to find)

Any suggestions for other similar fixs with sintered metal parts?

Gunner

Which part?

Better link

http://www.urban-armory.com/diagrams/mar1894.gif

Part #8, 9, and 10 (and 11)

He was missing the #10 pin..and I turned, annealed, *replaced it and
peened it into place gently.

Gunner

Why do I get the impression that the rifle has been overstressed?
Repeatedly.

http://en.wikipedia.org/wiki/Metal_fatigue

Sintered metal parts start out with a bazillion "cracks" (voids) when
they go into the furnace (or hot isostatic press) and hopefully come
out with none. Everything is controlled (temperature, pressure,
atmosphere) to get near net shape and avoid having to machine the
part. Not to say that it can't be repaired, but I'd rather go to the
dentist.

On Wed, 24 Apr 2013 07:28:47 -0700 (PDT), "Denis G."
wrote:

On Apr 23, 12:57*pm, Richard wrote:
On 4/24/2013 12:48 AM, Gunner Asch wrote:









On Tue, 23 Apr 2013 08:41:46 -0500,
wrote:

On 4/23/2013 7:57 PM, Gunner Asch wrote:
Fella brought over a gun part for a Marlin lever action..he was
missing a pin..so I made one up for him and installed it..and as I was
inspecting it..I noticed a rather serious crack starting to develop at
one end of the sintered metal part. * I fixed it by using my tig torch
and silver bearing flux..I packed the crack full of the heavy green
flux and zapped it with the tig..sealed it up well enough and I put a
slight layer over the area of the crack. After polishing it up with a
fine wire wheel, it looked good. But...is it?

How well does this sort of thing work with sintered metal parts?

Should I warn the guy to buy a new Widget? (Marlin just closed their
doors...so parts may become hard to find)

Any suggestions for other similar fixs with sintered metal parts?

Gunner

Which part?

Better link

http://www.urban-armory.com/diagrams/mar1894.gif

Part #8, 9, and 10 (and 11)

He was missing the #10 pin..and I turned, annealed, *replaced it and
peened it into place gently.

Gunner

Why do I get the impression that the rifle has been overstressed?
Repeatedly.

http://en.wikipedia.org/wiki/Metal_fatigue

Sintered metal parts start out with a bazillion "cracks" (voids) when
they go into the furnace (or hot isostatic press) and hopefully come
out with none. Everything is controlled (temperature, pressure,
atmosphere) to get near net shape and avoid having to machine the
part. Not to say that it can't be repaired, but I'd rather go to the
dentist.

Dollars to donuts, though, they ain't HIPping those gun parts. At
most, they're post-pressed and copper-infiltrated.

This part, though, looks like it wouldn't be practical to post-press.
And it's probably not infiltrated.

--
Ed Huntress

On Apr 24, 9:34*am, Ed Huntress wrote:
On Wed, 24 Apr 2013 07:28:47 -0700 (PDT), "Denis G."









wrote:
On Apr 23, 12:57*pm, Richard wrote:
On 4/24/2013 12:48 AM, Gunner Asch wrote:

On Tue, 23 Apr 2013 08:41:46 -0500,
wrote:

On 4/23/2013 7:57 PM, Gunner Asch wrote:
Fella brought over a gun part for a Marlin lever action..he was
missing a pin..so I made one up for him and installed it..and as I was
inspecting it..I noticed a rather serious crack starting to develop at
one end of the sintered metal part. * I fixed it by using my tig torch
and silver bearing flux..I packed the crack full of the heavy green
flux and zapped it with the tig..sealed it up well enough and I put a
slight layer over the area of the crack. After polishing it up with a
fine wire wheel, it looked good. But...is it?

How well does this sort of thing work with sintered metal parts?

Should I warn the guy to buy a new Widget? (Marlin just closed their
doors...so parts may become hard to find)

Any suggestions for other similar fixs with sintered metal parts?

Gunner

Which part?

Better link

http://www.urban-armory.com/diagrams/mar1894.gif

Part #8, 9, and 10 (and 11)

He was missing the #10 pin..and I turned, annealed, *replaced it and
peened it into place gently.

Gunner

Why do I get the impression that the rifle has been overstressed?
Repeatedly.

http://en.wikipedia.org/wiki/Metal_fatigue

Sintered metal parts start out with a bazillion "cracks" (voids) when
they go into the furnace (or hot isostatic press) and hopefully come
out with none. *Everything is controlled (temperature, pressure,
atmosphere) to get near net shape and avoid having to machine the
part. *Not to say that it can't be repaired, but I'd rather go to the
dentist.

Dollars to donuts, though, they ain't HIPping those gun parts. At
most, they're post-pressed and copper-infiltrated.

This part, though, looks like it wouldn't be practical to post-press.
And it's probably not infiltrated.

--
Ed Huntress

I was guessing that it was HIPped with the holes and final features
drilled and machined. (Certainly you can't pull apart the mold with
those sideways holes. The HIPped parts I've seen have copper powder
mixed in and with 30-50 ksi pressing you get pretty good part strength
and compaction and it's more state-of-the-art.
On the other hand, my experience is more with R&D and I don't know how
much throughput you'd get from HIPping vs. more conventional belt-
driven open air sintering furnaces, so maybe you're right.

On Wed, 24 Apr 2013 08:31:23 -0700 (PDT), "Denis G."
wrote:

On Apr 24, 9:34*am, Ed Huntress wrote:
On Wed, 24 Apr 2013 07:28:47 -0700 (PDT), "Denis G."









wrote:
On Apr 23, 12:57*pm, Richard wrote:
On 4/24/2013 12:48 AM, Gunner Asch wrote:

On Tue, 23 Apr 2013 08:41:46 -0500,
wrote:

On 4/23/2013 7:57 PM, Gunner Asch wrote:
Fella brought over a gun part for a Marlin lever action..he was
missing a pin..so I made one up for him and installed it..and as I was
inspecting it..I noticed a rather serious crack starting to develop at
one end of the sintered metal part. * I fixed it by using my tig torch
and silver bearing flux..I packed the crack full of the heavy green
flux and zapped it with the tig..sealed it up well enough and I put a
slight layer over the area of the crack. After polishing it up with a
fine wire wheel, it looked good. But...is it?

How well does this sort of thing work with sintered metal parts?

Should I warn the guy to buy a new Widget? (Marlin just closed their
doors...so parts may become hard to find)

Any suggestions for other similar fixs with sintered metal parts?

Gunner

Which part?

Better link

http://www.urban-armory.com/diagrams/mar1894.gif

Part #8, 9, and 10 (and 11)

He was missing the #10 pin..and I turned, annealed, *replaced it and
peened it into place gently.

Gunner

Why do I get the impression that the rifle has been overstressed?
Repeatedly.

http://en.wikipedia.org/wiki/Metal_fatigue

Sintered metal parts start out with a bazillion "cracks" (voids) when
they go into the furnace (or hot isostatic press) and hopefully come
out with none. *Everything is controlled (temperature, pressure,
atmosphere) to get near net shape and avoid having to machine the
part. *Not to say that it can't be repaired, but I'd rather go to the
dentist.

Dollars to donuts, though, they ain't HIPping those gun parts. At
most, they're post-pressed and copper-infiltrated.

This part, though, looks like it wouldn't be practical to post-press.
And it's probably not infiltrated.

--
Ed Huntress

I was guessing that it was HIPped with the holes and final features
drilled and machined. (Certainly you can't pull apart the mold with
those sideways holes. The HIPped parts I've seen have copper powder
mixed in and with 30-50 ksi pressing you get pretty good part strength
and compaction and it's more state-of-the-art.
On the other hand, my experience is more with R&D and I don't know how
much throughput you'd get from HIPping vs. more conventional belt-
driven open air sintering furnaces, so maybe you're right.

Unless there's some advance in HIPping since I was covering PM, it's
done in strippable metal cans -- one for each part. That drives costs
'way up. It's used mostly in aerospace, or it was.

HIPping of cast parts doesn't require cans, but PM does, or it did.

Ferrous parts that require some toughness and a bit of ductility often
are pressed, sintered, possibly hot post-pressed, and then
infiltrated, usually with copper. As an example, that's how they make
the bevel driven gears on DeWalt angle-head grinders. It's not cheap
compared to plain press-and-sinter, but it's a heck of a lot cheapter
than HIP. You get 100% density with infiltration, as you can with HIP.

--
Ed Huntress

On Apr 24, 10:47*am, Ed Huntress wrote:
On Wed, 24 Apr 2013 08:31:23 -0700 (PDT), "Denis G."









wrote:
On Apr 24, 9:34 am, Ed Huntress wrote:
On Wed, 24 Apr 2013 07:28:47 -0700 (PDT), "Denis G."

wrote:
On Apr 23, 12:57 pm, Richard wrote:
On 4/24/2013 12:48 AM, Gunner Asch wrote:

On Tue, 23 Apr 2013 08:41:46 -0500,
wrote:

On 4/23/2013 7:57 PM, Gunner Asch wrote:
Fella brought over a gun part for a Marlin lever action..he was
missing a pin..so I made one up for him and installed it..and as I was
inspecting it..I noticed a rather serious crack starting to develop at
one end of the sintered metal part. I fixed it by using my tig torch
and silver bearing flux..I packed the crack full of the heavy green
flux and zapped it with the tig..sealed it up well enough and I put a
slight layer over the area of the crack. After polishing it up with a
fine wire wheel, it looked good. But...is it?

How well does this sort of thing work with sintered metal parts?

Should I warn the guy to buy a new Widget? (Marlin just closed their
doors...so parts may become hard to find)

Any suggestions for other similar fixs with sintered metal parts?

Gunner

Which part?

Better link

http://www.urban-armory.com/diagrams/mar1894.gif

Part #8, 9, and 10 (and 11)

He was missing the #10 pin..and I turned, annealed, replaced it and
peened it into place gently.

Gunner

Why do I get the impression that the rifle has been overstressed?
Repeatedly.

http://en.wikipedia.org/wiki/Metal_fatigue

Sintered metal parts start out with a bazillion "cracks" (voids) when
they go into the furnace (or hot isostatic press) and hopefully come
out with none. Everything is controlled (temperature, pressure,
atmosphere) to get near net shape and avoid having to machine the
part. Not to say that it can't be repaired, but I'd rather go to the
dentist.

Dollars to donuts, though, they ain't HIPping those gun parts. At
most, they're post-pressed and copper-infiltrated.

This part, though, looks like it wouldn't be practical to post-press.
And it's probably not infiltrated.

--
Ed Huntress

I was guessing that it was HIPped with the holes and final features
drilled and machined. *(Certainly you can't pull apart the mold with
those sideways holes. *The HIPped parts I've seen have copper powder
mixed in and with 30-50 ksi pressing you get pretty good part strength
and compaction and it's more state-of-the-art.
On the other hand, my experience is more with R&D and I don't know how
much throughput you'd get from HIPping vs. more conventional belt-
driven open air sintering furnaces, so maybe you're right.

Unless there's some advance in HIPping since I was covering PM, it's
done in strippable metal cans -- one for each part. That drives costs
'way up. It's used mostly in aerospace, or it was.

HIPping of cast parts doesn't require cans, but PM does, or it did.

Ferrous parts that require some toughness and a bit of ductility often
are pressed, sintered, possibly hot post-pressed, and then
infiltrated, usually with copper. As an example, that's how they make
the bevel driven gears on DeWalt angle-head grinders. It's not cheap
compared to plain press-and-sinter, but it's a heck of a lot cheapter
than HIP. You get 100% density with infiltration, as you can with HIP.

--
Ed Huntress

You're right about the cans. They're crushed and disposable and the
HIPped material had to undergo final machining. It is more
expensive. I've been away from that business for a while and don't
remember everything. I pulled out one of my PM books and saw the
process that you describe. The PM that I'm familiar with had the all
powders premixed before pressing.

On Wed, 24 Apr 2013 11:47:14 -0400, Ed Huntress
wrote:

On Wed, 24 Apr 2013 08:31:23 -0700 (PDT), "Denis G."
wrote:

On Apr 24, 9:34*am, Ed Huntress wrote:
On Wed, 24 Apr 2013 07:28:47 -0700 (PDT), "Denis G."









wrote:
On Apr 23, 12:57*pm, Richard wrote:
On 4/24/2013 12:48 AM, Gunner Asch wrote:

On Tue, 23 Apr 2013 08:41:46 -0500,
wrote:

On 4/23/2013 7:57 PM, Gunner Asch wrote:
Fella brought over a gun part for a Marlin lever action..he was
missing a pin..so I made one up for him and installed it..and as I was
inspecting it..I noticed a rather serious crack starting to develop at
one end of the sintered metal part. * I fixed it by using my tig torch
and silver bearing flux..I packed the crack full of the heavy green
flux and zapped it with the tig..sealed it up well enough and I put a
slight layer over the area of the crack. After polishing it up with a
fine wire wheel, it looked good. But...is it?

How well does this sort of thing work with sintered metal parts?

Should I warn the guy to buy a new Widget? (Marlin just closed their
doors...so parts may become hard to find)

Any suggestions for other similar fixs with sintered metal parts?

Gunner

Which part?

Better link

http://www.urban-armory.com/diagrams/mar1894.gif

Part #8, 9, and 10 (and 11)

He was missing the #10 pin..and I turned, annealed, *replaced it and
peened it into place gently.

Gunner

Why do I get the impression that the rifle has been overstressed?
Repeatedly.

http://en.wikipedia.org/wiki/Metal_fatigue

Sintered metal parts start out with a bazillion "cracks" (voids) when
they go into the furnace (or hot isostatic press) and hopefully come
out with none. *Everything is controlled (temperature, pressure,
atmosphere) to get near net shape and avoid having to machine the
part. *Not to say that it can't be repaired, but I'd rather go to the
dentist.

Dollars to donuts, though, they ain't HIPping those gun parts. At
most, they're post-pressed and copper-infiltrated.

This part, though, looks like it wouldn't be practical to post-press.
And it's probably not infiltrated.

--
Ed Huntress

I was guessing that it was HIPped with the holes and final features
drilled and machined. (Certainly you can't pull apart the mold with
those sideways holes. The HIPped parts I've seen have copper powder
mixed in and with 30-50 ksi pressing you get pretty good part strength
and compaction and it's more state-of-the-art.
On the other hand, my experience is more with R&D and I don't know how
much throughput you'd get from HIPping vs. more conventional belt-
driven open air sintering furnaces, so maybe you're right.

Unless there's some advance in HIPping since I was covering PM, it's
done in strippable metal cans -- one for each part. That drives costs
'way up. It's used mostly in aerospace, or it was.

HIPping of cast parts doesn't require cans, but PM does, or it did.

Ferrous parts that require some toughness and a bit of ductility often
are pressed, sintered, possibly hot post-pressed, and then
infiltrated, usually with copper.

I mispoke there. They're EITHER post-pressed or infiltrated. I never
heard of doing both on the same part.

Either one can get you to 100% density, but infiltration usually
results in more impact resistance and ductility, but with slightly
less tensile strength.


As an example, that's how they make
the bevel driven gears on DeWalt angle-head grinders. It's not cheap
compared to plain press-and-sinter, but it's a heck of a lot cheapter
than HIP. You get 100% density with infiltration, as you can with HIP.

On Wed, 24 Apr 2013 09:06:13 -0700 (PDT), "Denis G."
wrote:

On Apr 24, 10:47*am, Ed Huntress wrote:
On Wed, 24 Apr 2013 08:31:23 -0700 (PDT), "Denis G."









wrote:
On Apr 24, 9:34 am, Ed Huntress wrote:
On Wed, 24 Apr 2013 07:28:47 -0700 (PDT), "Denis G."

wrote:
On Apr 23, 12:57 pm, Richard wrote:
On 4/24/2013 12:48 AM, Gunner Asch wrote:

On Tue, 23 Apr 2013 08:41:46 -0500,
wrote:

On 4/23/2013 7:57 PM, Gunner Asch wrote:
Fella brought over a gun part for a Marlin lever action..he was
missing a pin..so I made one up for him and installed it..and as I was
inspecting it..I noticed a rather serious crack starting to develop at
one end of the sintered metal part. I fixed it by using my tig torch
and silver bearing flux..I packed the crack full of the heavy green
flux and zapped it with the tig..sealed it up well enough and I put a
slight layer over the area of the crack. After polishing it up with a
fine wire wheel, it looked good. But...is it?

How well does this sort of thing work with sintered metal parts?

Should I warn the guy to buy a new Widget? (Marlin just closed their
doors...so parts may become hard to find)

Any suggestions for other similar fixs with sintered metal parts?

Gunner

Which part?

Better link

http://www.urban-armory.com/diagrams/mar1894.gif

Part #8, 9, and 10 (and 11)

He was missing the #10 pin..and I turned, annealed, replaced it and
peened it into place gently.

Gunner

Why do I get the impression that the rifle has been overstressed?
Repeatedly.

http://en.wikipedia.org/wiki/Metal_fatigue

Sintered metal parts start out with a bazillion "cracks" (voids) when
they go into the furnace (or hot isostatic press) and hopefully come
out with none. Everything is controlled (temperature, pressure,
atmosphere) to get near net shape and avoid having to machine the
part. Not to say that it can't be repaired, but I'd rather go to the
dentist.

Dollars to donuts, though, they ain't HIPping those gun parts. At
most, they're post-pressed and copper-infiltrated.

This part, though, looks like it wouldn't be practical to post-press.
And it's probably not infiltrated.

--
Ed Huntress

I was guessing that it was HIPped with the holes and final features
drilled and machined. *(Certainly you can't pull apart the mold with
those sideways holes. *The HIPped parts I've seen have copper powder
mixed in and with 30-50 ksi pressing you get pretty good part strength
and compaction and it's more state-of-the-art.
On the other hand, my experience is more with R&D and I don't know how
much throughput you'd get from HIPping vs. more conventional belt-
driven open air sintering furnaces, so maybe you're right.

Unless there's some advance in HIPping since I was covering PM, it's
done in strippable metal cans -- one for each part. That drives costs
'way up. It's used mostly in aerospace, or it was.

HIPping of cast parts doesn't require cans, but PM does, or it did.

Ferrous parts that require some toughness and a bit of ductility often
are pressed, sintered, possibly hot post-pressed, and then
infiltrated, usually with copper. As an example, that's how they make
the bevel driven gears on DeWalt angle-head grinders. It's not cheap
compared to plain press-and-sinter, but it's a heck of a lot cheapter
than HIP. You get 100% density with infiltration, as you can with HIP.

--
Ed Huntress

You're right about the cans. They're crushed and disposable and the
HIPped material had to undergo final machining. It is more
expensive. I've been away from that business for a while and don't
remember everything. I pulled out one of my PM books and saw the
process that you describe. The PM that I'm familiar with had the all
powders premixed before pressing.

What you're describing is by far the most common way it's done.

PM can be fascinating. By mixing powders and sintering at full
diffusion temperatures, you can produce alloys that are not possible
any other way.

For example, the most exotic of the high-speed-steels: Crucible CPM
REX 121. You can't make it by melting. That stuff is HIPped, BTW.

Regarding memory, I can empathize with that. d8-)

--
Ed Huntress

On Apr 24, 11:17*am, Ed Huntress wrote:
On Wed, 24 Apr 2013 09:06:13 -0700 (PDT), "Denis G."









wrote:
On Apr 24, 10:47*am, Ed Huntress wrote:
On Wed, 24 Apr 2013 08:31:23 -0700 (PDT), "Denis G."

wrote:
On Apr 24, 9:34 am, Ed Huntress wrote:
On Wed, 24 Apr 2013 07:28:47 -0700 (PDT), "Denis G."

wrote:
On Apr 23, 12:57 pm, Richard wrote:
On 4/24/2013 12:48 AM, Gunner Asch wrote:

On Tue, 23 Apr 2013 08:41:46 -0500,
wrote:

On 4/23/2013 7:57 PM, Gunner Asch wrote:
Fella brought over a gun part for a Marlin lever action..he was
missing a pin..so I made one up for him and installed it..and as I was
inspecting it..I noticed a rather serious crack starting to develop at
one end of the sintered metal part. I fixed it by using my tig torch
and silver bearing flux..I packed the crack full of the heavy green
flux and zapped it with the tig..sealed it up well enough and I put a
slight layer over the area of the crack. After polishing it up with a
fine wire wheel, it looked good. But...is it?

How well does this sort of thing work with sintered metal parts?

Should I warn the guy to buy a new Widget? (Marlin just closed their
doors...so parts may become hard to find)

Any suggestions for other similar fixs with sintered metal parts?

Gunner

Which part?

Better link

http://www.urban-armory.com/diagrams/mar1894.gif

Part #8, 9, and 10 (and 11)

He was missing the #10 pin..and I turned, annealed, replaced it and
peened it into place gently.

Gunner

Why do I get the impression that the rifle has been overstressed?
Repeatedly.

http://en.wikipedia.org/wiki/Metal_fatigue

Sintered metal parts start out with a bazillion "cracks" (voids) when
they go into the furnace (or hot isostatic press) and hopefully come
out with none. Everything is controlled (temperature, pressure,
atmosphere) to get near net shape and avoid having to machine the
part. Not to say that it can't be repaired, but I'd rather go to the
dentist.

Dollars to donuts, though, they ain't HIPping those gun parts. At
most, they're post-pressed and copper-infiltrated.

This part, though, looks like it wouldn't be practical to post-press.
And it's probably not infiltrated.

--
Ed Huntress

I was guessing that it was HIPped with the holes and final features
drilled and machined. *(Certainly you can't pull apart the mold with
those sideways holes. *The HIPped parts I've seen have copper powder
mixed in and with 30-50 ksi pressing you get pretty good part strength
and compaction and it's more state-of-the-art.
On the other hand, my experience is more with R&D and I don't know how
much throughput you'd get from HIPping vs. more conventional belt-
driven open air sintering furnaces, so maybe you're right.

Unless there's some advance in HIPping since I was covering PM, it's
done in strippable metal cans -- one for each part. That drives costs
'way up. It's used mostly in aerospace, or it was.

HIPping of cast parts doesn't require cans, but PM does, or it did.

Ferrous parts that require some toughness and a bit of ductility often
are pressed, sintered, possibly hot post-pressed, and then
infiltrated, usually with copper. As an example, that's how they make
the bevel driven gears on DeWalt angle-head grinders. It's not cheap
compared to plain press-and-sinter, but it's a heck of a lot cheapter
than HIP. You get 100% density with infiltration, as you can with HIP.

--
Ed Huntress

You're right about the cans. They're crushed and disposable and the
HIPped material had to undergo final machining. It is more
expensive. * I've been away from that business for a while and don't
remember everything. *I pulled out one of my PM books and saw the
process that you describe. *The PM that I'm familiar with had the all
powders premixed before pressing.

What you're describing is by far the most common way it's done.

PM can be fascinating. By mixing powders and sintering at full
diffusion temperatures, you can produce alloys that are not possible
any other way.

For example, the most exotic of the high-speed-steels: Crucible CPM
REX 121. You can't make it by melting. That stuff is HIPped, BTW.

Regarding memory, I can empathize with that. d8-)

--
Ed Huntress

PM is a neat subject. Although it get a lot of bad press for cheap
parts, I wonder how many people would sleep at night knowing that most
jet turbine blades are made with it.

What you're describing is by far the most common way it's done.

PM can be fascinating. By mixing powders and sintering at full
diffusion temperatures, you can produce alloys that are not possible
any other way.

For example, the most exotic of the high-speed-steels: Crucible CPM
REX 121. You can't make it by melting. That stuff is HIPped, BTW.

Regarding memory, I can empathize with that. d8-)

I have a book called "The Component Contribution Engine Progress Through
the Specialist Manufacturers" by Alan Baker ISBN 0 09 136290 3 and it
mentions the use of what they call powder forging being used by GKN to
produce conrods for the Porsche 928. The book dates from 1979 and the
928 1978 so looks like some high performance applications have been
around for a while. I presume this would be an application of what
you're referring to as HIPed. IIRC the hot initially powder form is
placed in dies and struck to produce a 100% part with high dimensional
and weight accuracy compared to standard forging processes.

BTW the book is a fascinating read if you haven't read it already and it
looks like it's available cheaply on Amazon. Maybe a little dated in the
last 34 years but still a good read.

On Wed, 24 Apr 2013 09:46:33 -0700 (PDT), "Denis G."
wrote:

On Apr 24, 11:17*am, Ed Huntress wrote:
On Wed, 24 Apr 2013 09:06:13 -0700 (PDT), "Denis G."









wrote:
On Apr 24, 10:47*am, Ed Huntress wrote:
On Wed, 24 Apr 2013 08:31:23 -0700 (PDT), "Denis G."

wrote:
On Apr 24, 9:34 am, Ed Huntress wrote:
On Wed, 24 Apr 2013 07:28:47 -0700 (PDT), "Denis G."

wrote:
On Apr 23, 12:57 pm, Richard wrote:
On 4/24/2013 12:48 AM, Gunner Asch wrote:

On Tue, 23 Apr 2013 08:41:46 -0500,
wrote:

On 4/23/2013 7:57 PM, Gunner Asch wrote:
Fella brought over a gun part for a Marlin lever action..he was
missing a pin..so I made one up for him and installed it..and as I was
inspecting it..I noticed a rather serious crack starting to develop at
one end of the sintered metal part. I fixed it by using my tig torch
and silver bearing flux..I packed the crack full of the heavy green
flux and zapped it with the tig..sealed it up well enough and I put a
slight layer over the area of the crack. After polishing it up with a
fine wire wheel, it looked good. But...is it?

How well does this sort of thing work with sintered metal parts?

Should I warn the guy to buy a new Widget? (Marlin just closed their
doors...so parts may become hard to find)

Any suggestions for other similar fixs with sintered metal parts?

Gunner

Which part?

Better link

http://www.urban-armory.com/diagrams/mar1894.gif

Part #8, 9, and 10 (and 11)

He was missing the #10 pin..and I turned, annealed, replaced it and
peened it into place gently.

Gunner

Why do I get the impression that the rifle has been overstressed?
Repeatedly.

http://en.wikipedia.org/wiki/Metal_fatigue

Sintered metal parts start out with a bazillion "cracks" (voids) when
they go into the furnace (or hot isostatic press) and hopefully come
out with none. Everything is controlled (temperature, pressure,
atmosphere) to get near net shape and avoid having to machine the
part. Not to say that it can't be repaired, but I'd rather go to the
dentist.

Dollars to donuts, though, they ain't HIPping those gun parts. At
most, they're post-pressed and copper-infiltrated.

This part, though, looks like it wouldn't be practical to post-press.
And it's probably not infiltrated.

--
Ed Huntress

I was guessing that it was HIPped with the holes and final features
drilled and machined. *(Certainly you can't pull apart the mold with
those sideways holes. *The HIPped parts I've seen have copper powder
mixed in and with 30-50 ksi pressing you get pretty good part strength
and compaction and it's more state-of-the-art.
On the other hand, my experience is more with R&D and I don't know how
much throughput you'd get from HIPping vs. more conventional belt-
driven open air sintering furnaces, so maybe you're right.

Unless there's some advance in HIPping since I was covering PM, it's
done in strippable metal cans -- one for each part. That drives costs
'way up. It's used mostly in aerospace, or it was.

HIPping of cast parts doesn't require cans, but PM does, or it did.

Ferrous parts that require some toughness and a bit of ductility often
are pressed, sintered, possibly hot post-pressed, and then
infiltrated, usually with copper. As an example, that's how they make
the bevel driven gears on DeWalt angle-head grinders. It's not cheap
compared to plain press-and-sinter, but it's a heck of a lot cheapter
than HIP. You get 100% density with infiltration, as you can with HIP.

--
Ed Huntress

You're right about the cans. They're crushed and disposable and the
HIPped material had to undergo final machining. It is more
expensive. * I've been away from that business for a while and don't
remember everything. *I pulled out one of my PM books and saw the
process that you describe. *The PM that I'm familiar with had the all
powders premixed before pressing.

What you're describing is by far the most common way it's done.

PM can be fascinating. By mixing powders and sintering at full
diffusion temperatures, you can produce alloys that are not possible
any other way.

For example, the most exotic of the high-speed-steels: Crucible CPM
REX 121. You can't make it by melting. That stuff is HIPped, BTW.

Regarding memory, I can empathize with that. d8-)

--
Ed Huntress

PM is a neat subject. Although it get a lot of bad press for cheap
parts, I wonder how many people would sleep at night knowing that most
jet turbine blades are made with it.

Right. And the connecting rods in a lot of automobile engines. PM is
all over the place, and it's often hard to identify, particularly when
it's been post-pressed. It looks like a high-quality forging. And it
often performs as well or even better than one.

It's come a long way from the days when it was used for cheap parts
that often were brittle and weak.

--
Ed Huntress

On Wed, 24 Apr 2013 17:48:52 +0100, David Billington
wrote:


What you're describing is by far the most common way it's done.

PM can be fascinating. By mixing powders and sintering at full
diffusion temperatures, you can produce alloys that are not possible
any other way.

For example, the most exotic of the high-speed-steels: Crucible CPM
REX 121. You can't make it by melting. That stuff is HIPped, BTW.

Regarding memory, I can empathize with that. d8-)

I have a book called "The Component Contribution Engine Progress Through
the Specialist Manufacturers" by Alan Baker ISBN 0 09 136290 3 and it
mentions the use of what they call powder forging being used by GKN to
produce conrods for the Porsche 928. The book dates from 1979 and the
928 1978 so looks like some high performance applications have been
around for a while.

Yes, I remember that. The 928 engine used a lot of advanced
technologies. Porsche was trying all their new tricks, including
running the pistons in aluminum cylinders. Unlike the Chevy Vega, they
got it right.

They may have sleeved the 928 later, but it started as a hypereutectic
aluminum block with the pistons running directly in the block.

I presume this would be an application of what
you're referring to as HIPed. IIRC the hot initially powder form is
placed in dies and struck to produce a 100% part with high dimensional
and weight accuracy compared to standard forging processes.

I doubt if they were HIPped. I saw Chevy con rods made of PM in the
mid-'90s, and they were being made with conventional sintering and
then post-pressing to increase the density.


BTW the book is a fascinating read if you haven't read it already and it
looks like it's available cheaply on Amazon. Maybe a little dated in the
last 34 years but still a good read.

On 24/04/13 18:16, Ed Huntress wrote:
On Wed, 24 Apr 2013 17:48:52 +0100, David Billington
wrote:

What you're describing is by far the most common way it's done.

PM can be fascinating. By mixing powders and sintering at full
diffusion temperatures, you can produce alloys that are not possible
any other way.

For example, the most exotic of the high-speed-steels: Crucible CPM
REX 121. You can't make it by melting. That stuff is HIPped, BTW.

Regarding memory, I can empathize with that. d8-)

I have a book called "The Component Contribution Engine Progress Through
the Specialist Manufacturers" by Alan Baker ISBN 0 09 136290 3 and it
mentions the use of what they call powder forging being used by GKN to
produce conrods for the Porsche 928. The book dates from 1979 and the
928 1978 so looks like some high performance applications have been
around for a while.
Yes, I remember that. The 928 engine used a lot of advanced
technologies. Porsche was trying all their new tricks, including
running the pistons in aluminum cylinders. Unlike the Chevy Vega, they
got it right.

I mentioned the Vega engine to a mate that works in engine development
and he found it hard to believe they went all that trouble developing
the block process then put an iron head on it to save money but then
maybe that was GMs way. I do remember back in the 70s the engine had a
bad reputation.


They may have sleeved the 928 later, but it started as a hypereutectic
aluminum block with the pistons running directly in the block.
IIRC one of the Mercedes Benz engines is the same, a V8 I think
/
/

I presume this would be an application of what
you're referring to as HIPed. IIRC the hot initially powder form is
placed in dies and struck to produce a 100% part with high dimensional
and weight accuracy compared to standard forging processes.
I doubt if they were HIPped. I saw Chevy con rods made of PM in the
mid-'90s, and they were being made with conventional sintering and
then post-pressing to increase the density.
I looked up what HIP was and I think you're right that wasn't what was
used rather heating to a high temp and striking the powder pressing to
consolidate the material. I noticed a youtube video on HIP so will watch
that shortly.


BTW the book is a fascinating read if you haven't read it already and it
looks like it's available cheaply on Amazon. Maybe a little dated in the
last 34 years but still a good read.

On Wed, 24 Apr 2013 19:09:50 +0100, David Billington
wrote:

On 24/04/13 18:16, Ed Huntress wrote:
On Wed, 24 Apr 2013 17:48:52 +0100, David Billington
wrote:

What you're describing is by far the most common way it's done.

PM can be fascinating. By mixing powders and sintering at full
diffusion temperatures, you can produce alloys that are not possible
any other way.

For example, the most exotic of the high-speed-steels: Crucible CPM
REX 121. You can't make it by melting. That stuff is HIPped, BTW.

Regarding memory, I can empathize with that. d8-)

I have a book called "The Component Contribution Engine Progress Through
the Specialist Manufacturers" by Alan Baker ISBN 0 09 136290 3 and it
mentions the use of what they call powder forging being used by GKN to
produce conrods for the Porsche 928. The book dates from 1979 and the
928 1978 so looks like some high performance applications have been
around for a while.
Yes, I remember that. The 928 engine used a lot of advanced
technologies. Porsche was trying all their new tricks, including
running the pistons in aluminum cylinders. Unlike the Chevy Vega, they
got it right.

I mentioned the Vega engine to a mate that works in engine development
and he found it hard to believe they went all that trouble developing
the block process then put an iron head on it to save money but then
maybe that was GMs way. I do remember back in the 70s the engine had a
bad reputation.

There were several basic engineering screw-ups, some so obvious that
it was hard to believe.

You may remember the Cosworth version of the Vega, which had an
aluminum, dual-cam Cosworth head on the same engine block. Some car
enthusiast wrote a letter to one of the two big US sports-car
magazines -- Sports Car Graphic or Road & Track -- and asked how you
could tell a regular Vega from a Cosworth Vega. There was no obvious
Cosworth insignia on the car; just one little badge somewhere.

"Look under the car," said the magazine editor. "If there's a puddle
of oil under it, it's a regular Vega." d8-)



They may have sleeved the 928 later, but it started as a hypereutectic
aluminum block with the pistons running directly in the block.
IIRC one of the Mercedes Benz engines is the same, a V8 I think
/
/

I presume this would be an application of what
you're referring to as HIPed. IIRC the hot initially powder form is
placed in dies and struck to produce a 100% part with high dimensional
and weight accuracy compared to standard forging processes.
I doubt if they were HIPped. I saw Chevy con rods made of PM in the
mid-'90s, and they were being made with conventional sintering and
then post-pressing to increase the density.
I looked up what HIP was and I think you're right that wasn't what was
used rather heating to a high temp and striking the powder pressing to
consolidate the material. I noticed a youtube video on HIP so will watch
that shortly.


BTW the book is a fascinating read if you haven't read it already and it
looks like it's available cheaply on Amazon. Maybe a little dated in the
last 34 years but still a good read.

On 24/04/13 19:26, Ed Huntress wrote:
On Wed, 24 Apr 2013 19:09:50 +0100, David Billington
wrote:

On 24/04/13 18:16, Ed Huntress wrote:
On Wed, 24 Apr 2013 17:48:52 +0100, David Billington
wrote:

What you're describing is by far the most common way it's done.

PM can be fascinating. By mixing powders and sintering at full
diffusion temperatures, you can produce alloys that are not possible
any other way.

For example, the most exotic of the high-speed-steels: Crucible CPM
REX 121. You can't make it by melting. That stuff is HIPped, BTW.

Regarding memory, I can empathize with that. d8-)

I have a book called "The Component Contribution Engine Progress Through
the Specialist Manufacturers" by Alan Baker ISBN 0 09 136290 3 and it
mentions the use of what they call powder forging being used by GKN to
produce conrods for the Porsche 928. The book dates from 1979 and the
928 1978 so looks like some high performance applications have been
around for a while.
Yes, I remember that. The 928 engine used a lot of advanced
technologies. Porsche was trying all their new tricks, including
running the pistons in aluminum cylinders. Unlike the Chevy Vega, they
got it right.
I mentioned the Vega engine to a mate that works in engine development
and he found it hard to believe they went all that trouble developing
the block process then put an iron head on it to save money but then
maybe that was GMs way. I do remember back in the 70s the engine had a
bad reputation.
There were several basic engineering screw-ups, some so obvious that
it was hard to believe.

You may remember the Cosworth version of the Vega, which had an
aluminum, dual-cam Cosworth head on the same engine block. Some car
enthusiast wrote a letter to one of the two big US sports-car
magazines -- Sports Car Graphic or Road & Track -- and asked how you
could tell a regular Vega from a Cosworth Vega. There was no obvious
Cosworth insignia on the car; just one little badge somewhere.

"Look under the car," said the magazine editor. "If there's a puddle
of oil under it, it's a regular Vega." d8-)
Yes I was aware of a Cosworth version, maybe the wheels give it away as
well. The oil leak maybe like the old joke about British bikes, it's not
leaking oil just marking its territory!.


They may have sleeved the 928 later, but it started as a hypereutectic
aluminum block with the pistons running directly in the block.
IIRC one of the Mercedes Benz engines is the same, a V8 I think
/
/
I presume this would be an application of what
you're referring to as HIPed. IIRC the hot initially powder form is
placed in dies and struck to produce a 100% part with high dimensional
and weight accuracy compared to standard forging processes.
I doubt if they were HIPped. I saw Chevy con rods made of PM in the
mid-'90s, and they were being made with conventional sintering and
then post-pressing to increase the density.
I looked up what HIP was and I think you're right that wasn't what was
used rather heating to a high temp and striking the powder pressing to
consolidate the material. I noticed a youtube video on HIP so will watch
that shortly.

BTW the book is a fascinating read if you haven't read it already and it
looks like it's available cheaply on Amazon. Maybe a little dated in the
last 34 years but still a good read.

"Ed Huntress" wrote in message
...
On Wed, 24 Apr 2013 19:09:50 +0100, David Billington
wrote:

On 24/04/13 18:16, Ed Huntress wrote:
On Wed, 24 Apr 2013 17:48:52 +0100, David Billington
wrote:

What you're describing is by far the most common way it's done.

PM can be fascinating. By mixing powders and sintering at full
diffusion temperatures, you can produce alloys that are not possible
any other way.

For example, the most exotic of the high-speed-steels: Crucible CPM
REX 121. You can't make it by melting. That stuff is HIPped, BTW.

Regarding memory, I can empathize with that. d8-)

I have a book called "The Component Contribution Engine Progress
Through
the Specialist Manufacturers" by Alan Baker ISBN 0 09 136290 3 and it
mentions the use of what they call powder forging being used by GKN to
produce conrods for the Porsche 928. The book dates from 1979 and the
928 1978 so looks like some high performance applications have been
around for a while.
Yes, I remember that. The 928 engine used a lot of advanced
technologies. Porsche was trying all their new tricks, including
running the pistons in aluminum cylinders. Unlike the Chevy Vega, they
got it right.

I mentioned the Vega engine to a mate that works in engine development
and he found it hard to believe they went all that trouble developing
the block process then put an iron head on it to save money but then
maybe that was GMs way. I do remember back in the 70s the engine had a
bad reputation.

There were several basic engineering screw-ups, some so obvious that
it was hard to believe.

You may remember the Cosworth version of the Vega, which had an
aluminum, dual-cam Cosworth head on the same engine block. Some car
enthusiast wrote a letter to one of the two big US sports-car
magazines -- Sports Car Graphic or Road & Track -- and asked how you
could tell a regular Vega from a Cosworth Vega. There was no obvious
Cosworth insignia on the car; just one little badge somewhere.

"Look under the car," said the magazine editor. "If there's a puddle
of oil under it, it's a regular Vega." d8-)


I do not know the Vega engine, but it sounds like the result of a process I
have seen too many times.
A senior executive gathers the engineering group and says, "We need to
reduce the cost of goods by $100 and pull in the schedule by 2 months. Give
me any ideas you have. Don't be bashful, we are just brainstorming here"
After some silence he says, " Oh, come on, I know you have ideas."
Finally some competent but naive fellow will meekly speak up and say, "well,
we COULD do X, but of course that would mean Y." The fellow just assumed
anyone in his right mind would never want Y to happen.
The executive who does not really understand the technical implications of Y
gets all excited, "Really! We can do that? That makes me very happy, lets do
it!"
As others around the table try to gently tell him the problem with that
decision, he is not even listening as he mentally tallies his year end
bonus.

On Wed, 24 Apr 2013 12:00:39 -0700, "anorton"
wrote:


"Ed Huntress" wrote in message
.. .
On Wed, 24 Apr 2013 19:09:50 +0100, David Billington
wrote:

On 24/04/13 18:16, Ed Huntress wrote:
On Wed, 24 Apr 2013 17:48:52 +0100, David Billington
wrote:

What you're describing is by far the most common way it's done.

PM can be fascinating. By mixing powders and sintering at full
diffusion temperatures, you can produce alloys that are not possible
any other way.

For example, the most exotic of the high-speed-steels: Crucible CPM
REX 121. You can't make it by melting. That stuff is HIPped, BTW.

Regarding memory, I can empathize with that. d8-)

I have a book called "The Component Contribution Engine Progress
Through
the Specialist Manufacturers" by Alan Baker ISBN 0 09 136290 3 and it
mentions the use of what they call powder forging being used by GKN to
produce conrods for the Porsche 928. The book dates from 1979 and the
928 1978 so looks like some high performance applications have been
around for a while.
Yes, I remember that. The 928 engine used a lot of advanced
technologies. Porsche was trying all their new tricks, including
running the pistons in aluminum cylinders. Unlike the Chevy Vega, they
got it right.

I mentioned the Vega engine to a mate that works in engine development
and he found it hard to believe they went all that trouble developing
the block process then put an iron head on it to save money but then
maybe that was GMs way. I do remember back in the 70s the engine had a
bad reputation.

There were several basic engineering screw-ups, some so obvious that
it was hard to believe.

You may remember the Cosworth version of the Vega, which had an
aluminum, dual-cam Cosworth head on the same engine block. Some car
enthusiast wrote a letter to one of the two big US sports-car
magazines -- Sports Car Graphic or Road & Track -- and asked how you
could tell a regular Vega from a Cosworth Vega. There was no obvious
Cosworth insignia on the car; just one little badge somewhere.

"Look under the car," said the magazine editor. "If there's a puddle
of oil under it, it's a regular Vega." d8-)


I do not know the Vega engine, but it sounds like the result of a process I
have seen too many times.
A senior executive gathers the engineering group and says, "We need to
reduce the cost of goods by $100 and pull in the schedule by 2 months. Give
me any ideas you have. Don't be bashful, we are just brainstorming here"
After some silence he says, " Oh, come on, I know you have ideas."
Finally some competent but naive fellow will meekly speak up and say, "well,
we COULD do X, but of course that would mean Y." The fellow just assumed
anyone in his right mind would never want Y to happen.
The executive who does not really understand the technical implications of Y
gets all excited, "Really! We can do that? That makes me very happy, lets do
it!"
As others around the table try to gently tell him the problem with that
decision, he is not even listening as he mentally tallies his year end
bonus.

I don't know what happened with the Vega design. It had so much going
for it when the first design ideas were made public; then they built
it and the problems started cropping up; then the engineering details
came out, and even us amateur car buffs said, "Whaaa?"

It's not like they didn't know about the differential expansion
problems.

--
Ed Huntress