We are working on a new aluminum fixture. It is basically an aluminum
spine with many 6061-T6 pins sticking out. Currently we drill the
holes inside the spine and hammer the 5/32" 6061-T6 pins inside. Is
there anyway to cast aluminum with many 6061-T6 pins embedded (they
will stick out after the casting)?

Thanks........... Ken

Opportunities are never lost. The other fellow takes those you miss.

| Torrey Hills Technologies, LLC |
| www.threerollmill.com |
| www.torreyhillstech.com |

It may be possible to cast the 6061-T6 pins in the aluminum (depends on size
and configuration) but they will of course no longer be T6 and the entire
assembly would need to be heat treated.

The question I would have is why not cast the pins as part of the spine
casting (i.e. pins and spine all one casting)?

Also what if the pins were made in stainless steel and the aluminum cast
around them.

I would need to know more about the object you are casting but to take full
advantage of the casting process you should consider a way to eliminate the
extra operation of making the pins.

Mark


"Ink Maker" wrote in message
oups.com...
We are working on a new aluminum fixture. It is basically an aluminum
spine with many 6061-T6 pins sticking out. Currently we drill the
holes inside the spine and hammer the 5/32" 6061-T6 pins inside. Is
there anyway to cast aluminum with many 6061-T6 pins embedded (they
will stick out after the casting)?

Thanks........... Ken

Opportunities are never lost. The other fellow takes those you miss.

| Torrey Hills Technologies, LLC |
| www.threerollmill.com |
| www.torreyhillstech.com |

"Ink Maker" wrote in message
oups.com...
We are working on a new aluminum fixture. It is basically an aluminum
spine with many 6061-T6 pins sticking out. Currently we drill the
holes inside the spine and hammer the 5/32" 6061-T6 pins inside. Is
there anyway to cast aluminum with many 6061-T6 pins embedded (they
will stick out after the casting)?

Thanks........... Ken

Opportunities are never lost. The other fellow takes those you miss.

| Torrey Hills Technologies, LLC |
| www.threerollmill.com |
| www.torreyhillstech.com |


T6 is a heat treatment and aging process. If you cast them in, the part in,
and near the casting will no longer be T6!


Steve R.


--
Return address munged to bugger up spammers

On Tue, 14 Aug 2007 21:49:49 -0000, Ink Maker
wrote:

We are working on a new aluminum fixture. It is basically an aluminum
spine with many 6061-T6 pins sticking out. Currently we drill the
holes inside the spine and hammer the 5/32" 6061-T6 pins inside. Is
there anyway to cast aluminum with many 6061-T6 pins embedded (they
will stick out after the casting)?


absolutely no practical way possible of doing what you ask.

....which was 'can I cast aluminium with aluminium chaplets'.

absolutely not. aluminium has such a heat transfer that molten
aluminium coming into contact with aluminium pins would soon have them
molten and fluid.

Stealth Pilot

"Stealth Pilot" wrote in message
...
On Tue, 14 Aug 2007 21:49:49 -0000, Ink Maker
wrote:

We are working on a new aluminum fixture. It is basically an aluminum
spine with many 6061-T6 pins sticking out. Currently we drill the
holes inside the spine and hammer the 5/32" 6061-T6 pins inside. Is
there anyway to cast aluminum with many 6061-T6 pins embedded (they
will stick out after the casting)?


absolutely no practical way possible of doing what you ask.

...which was 'can I cast aluminium with aluminium chaplets'.

absolutely not. aluminium has such a heat transfer that molten
aluminium coming into contact with aluminium pins would soon have them
molten and fluid.

Stealth Pilot

One thing to keep in mind is that you can cast 6061. It's not usually listed
as a casting alloy but, among the wrought alloys, it's least likely to crack
upon cooling. Lots of castings are made with 6061.

So it would be possible to cast the whole thing as one piece. Then you'd
have to figure out how to machine the protruding "pins." g Of course, to
get the hardness back, you'd have to heat treat the whole deal.

That doesn't sound like a practical way to go, but it might lead to some
other solution.

--
Ed Huntress

On Aug 14, 10:49 pm, Ink Maker wrote:
We are working on a new aluminum fixture. It is basically an aluminum
spine with many 6061-T6 pins sticking out. Currently we drill the
holes inside the spine and hammer the 5/32" 6061-T6 pins inside. Is
there anyway to cast aluminum with many 6061-T6 pins embedded (they
will stick out after the casting)?

Thanks........... Ken

First let me say that I have no experience in aluminum casting. But I
took a look at your web site and found the anodizing racks. I suspect
you are now making the racks using a machined spline, not a cast one.
It looks as if the casting the pins would be difficult because they
are fairly long compared to the diameter and it would be hard to get
the aluminum to flow to the end away from the spline. Injection
molding might work. But it also might be possible to use aluminum
pins and cast the spline. The pins would melt where they go thru the
spline and would not be in the T6 condition where they got really
hot. You might be able to compensate for this by having the pins
( after casting ) be thicker near the spline.

But I would really think about using stainless pins and casting the
aluminum around them. You could probably go with slightly thinner
stainless as it is stiffer than aluminum.

Again I have no experience.

Dan

"Stealth Pilot" wrote in message
...

absolutely not. aluminium has such a heat transfer that molten
aluminium coming into contact with aluminium pins would soon have them
molten and fluid.

Stealth Pilot

I disagree. Daily we cast aluminum against aluminum, without two parts
knitting together, sucessfully. Also we know how to cast aluminum inserts
into aluminum. The problem has to consider the relative mass of the
aluminum pins vs. the amount, shape and pouring temperature of the aluminum
that is cast around the aluminum pins.

However, I would allow it is a difficult situation but not necessarily
impossible.

Mark

"Mark Fields" wrote in message
...

"Stealth Pilot" wrote in message
...

absolutely not. aluminium has such a heat transfer that molten
aluminium coming into contact with aluminium pins would soon have them
molten and fluid.

Stealth Pilot

I disagree. Daily we cast aluminum against aluminum, without two parts
knitting together, sucessfully. Also we know how to cast aluminum inserts
into aluminum. The problem has to consider the relative mass of the
aluminum pins vs. the amount, shape and pouring temperature of the
aluminum that is cast around the aluminum pins.

However, I would allow it is a difficult situation but not necessarily
impossible.

I agree. After casting, the 6061 would require a solution anneal before it
could be re-hardened. Heating the casting to 950 degrees F will provide
the solution anneal. Then it's just a matter of soaking the castings for
the prescribed period of time at the proper temperature to achieve the
desired T condition. Aging can not be accomplished without going through
the solution anneal process.

As Ed alluded, 6061 can be cast, too, although it doesn't cast as well as
other alloys. Years ago I machined a large number of cast 6061 pieces,
parts for a defense contract.

Harold