This process sounds more like brazing than welding, at least as seen by
the steel.

Joe Gwinn

----------------------------------------------------------------

The Holy Grail of Welding: Steel + Aluminum -- Auto Industry¹s Drive
for Light-Weight Parts Fuels Voestalpine¹s Hunt for New Process


...http://www.wsj.com/articles/the-holy...teel-aluminum-
1423528185


John W. Miller
Feb. 9, 2015 7:29 p.m. ET (Wall Street Journal)


LINZ, Austria‹Austrian welder Alois Leitner fuses strips of steel and
aluminum alloys in what could be part of a historic breakthrough.

³They taught us in engineering school this was impossible,² said Mr.
Leitner, who works for Linz-based Voestalpine AG , Europe¹s
third-biggest steelmaker.

Mr. Leitner¹s work in a small lab on the outskirts of this industrial
town near the Czech border seems simple enough‹but these two basic
metals are famously incompatible. Solving the riddle of how to combine
them has long been considered a Holy Grail for big metals and auto
companies.

Voestalpine¹s process is neither easy nor cheap. The company uses a
special solder and torches just hot enough to melt aluminum but not
steel. The process, called cold metal transfer, employs an argon gas to
avoid oxidation. Finally, the steel is coated with zinc to bind the
steel, solder and aluminum.

³You need to hit all the parameters in the right way to achieve the
right properties,² said Voestalpine spokesman Peter Felsbach. The
company said its technique is two to three times as expensive as the
riveting and gluing techniques now used. It hopes to shave costs by a
third to make the process suitable for high-end autos.
Welder Alois Leitner shows a weld between steel and aluminum pieces
that used a cold metal transfer technique that has piqued the interest
of auto makers now shifting to lighter weight materials for improved
fuel economy. ENLARGE
Welder Alois Leitner shows a weld between steel and aluminum pieces
that used a cold metal transfer technique that has piqued the interest
of auto makers now shifting to lighter weight materials for improved
fuel economy. Photo: John W. Miller/The Wall Street Journal

To make it commercially feasible, the company said it would need more
customers, which would help pay for the tinkering necessary to refine
the process and make it less expensive.
Advertisement

The payoff is potentially huge.

For decades, steel and aluminum makers have competed for car parts‹from
hoods to engine blocks‹touting their metal as stronger, cheaper and
lighter, and the other as inferior. Being able to readily combine the
two would increase auto makers¹ portfolio of parts, adding a palette
that benefits from steel¹s strength and aluminum¹s lightness.

Luxury-car maker Audi AG first contacted Voestalpine to help it join
³materials like steel and aluminum or fiber-reinforced plastics,²
according to the auto maker. ³Welding aluminum and steel is a very
promising technology development,² it said.

³We had always said it can¹t be done,² said Dick Evans, chairman of
Constellium NV, a major producer of aluminum sheet for the auto
industry that doesn¹t currently have a hybrid product on the market.

The interest is rising as mass-market auto makers, led by Ford Motor
Co. with its 2015 F-150 pickup truck, embrace lighter but more
expensive aluminum to meet new fuel standards. Honda Motor Co. uses
another technique to fuse steel and aluminum, but its application so
far has been limited. A handful of other top metal and auto firms have
explored how to make hybrid parts.

Steelmakers are fighting back by developing lighter, harder steels that
can lessen the weight difference with aluminum. They even can weld
together steel pieces of different weight and thickness, to piece
together a part that is only as thick as it needs to be throughout its
surface.

Under Chief Executive Wolfgang Eder, Voestalpine has developed an
automotive niche market with BMW AG , Daimler AG ¹s Mercedes-Benz and
Volkswagen AG , which owns Audi, Seat, Porsche and Bentley. ³We are not
competitive in commodity steel in a high-cost country like Austria,²
Mr. Eder said in an interview. ³We need to focus on high tech.²

The quest to weld the two metals is important enough for the U.S.
government to be involved in research. Its scientists say success could
make cars lighter and streamline car making. Zhili Feng, who researches
how cars are made at the Department of Energy¹s laboratory in Oak
Ridge, Tenn., said a compact car can have as many as 6,000 spot welds.

³Every extra weld adds cost,² he said. ³If you could have a hybrid
part, the welds have to be made with high quality and
cost-effectively.² Hybrid steel-aluminum parts ³are something everybody
is working on,² said Mr. Feng. ³Nobody has really figured out what is
the best technology to weld aluminum to steel. Right now, it is a wide
open field.²

Voestalpine¹s work is known throughout the industry, he said.

Combinations ³aren¹t new, they¹re just expanding in importance,² said
Todd Summe, director of automotive technology for Novelis Inc., the
largest global producer of automotive sheet aluminum.

Novelis said its researchers are testing new technologies for
mixed-material solutions, such as aluminum-steel hybrids. The company
has no commercial products specifically designed for hybrid
aluminum-steel structures, but Mr. Summe said its products have been
successfully paired with steel using adhesives and mechanical fasteners
for quite some time.

On a recent day, Mr. Leitner, whose services also are used by a welding
company called Fronius International GmbH, a partner in the
development, applies a special solder to two car parts‹one zinc-coated
steel and one aluminum‹and fires up his torch. Slowly running down the
joint, the 1,000 degree Fahrenheit flames melted the two pieces
together.

What resulted was a part so cohesive it can be stamped as if it were
once piece. ³We could use this for exposed, outside parts of the car,²
said Voestalpine¹s Mr. Eder. ³You could exchange today¹s laser-welded
steel parts with steel-aluminum parts.²

Audi and other customers say they are interested if costs can be
brought down, according to Voestalpine. It is working on doing that by,
for example, trying to make the welding process faster and tinkering
with the alloy of the film between the two metals.

³We were the first to figure this out, and now we¹re working on making
it more cost-effective,² said Mr. Eder. ³People used to say it was too
expensive to make a whole car out of aluminum.²


----------------------------------------------------------------

On 16-Feb-15 6:51 AM, Joe Gwinn wrote:

This process sounds more like brazing than welding, at least as seen by
the steel.

Joe Gwinn

----------------------------------------------------------------

The Holy Grail of Welding: Steel + Aluminum -- Auto Industry¹s Drive
for Light-Weight Parts Fuels Voestalpine¹s Hunt for New Process


..http://www.wsj.com/articles/the-holy...teel-aluminum-
1423528185



Seems to be behind a pay wall.

Sounds interesting.

The ignorance of the news media is astounding.

Steel welded to aluminum was achieved on a commercially successful basis
years (probably decades) ago by the high energy materials folks - ie,
explosive welding. As far as I recall they simply made long strips of
interface welded explosively, and those were welded by normal means to
put aluminum superstructures on top of steel hulls.

Here's one, there are others: http://triplate.com

--
Cats, coffee, chocolate...vices to live by
Please don't feed the trolls. Killfile and ignore them so they will go away.

On Mon, 16 Feb 2015 10:27:10 +0800, McAvity
wrote:

On 16-Feb-15 6:51 AM, Joe Gwinn wrote:

This process sounds more like brazing than welding, at least as seen by
the steel.

Joe Gwinn

----------------------------------------------------------------

The Holy Grail of Welding: Steel + Aluminum -- Auto Industry¹s Drive
for Light-Weight Parts Fuels Voestalpine¹s Hunt for New Process


..http://www.wsj.com/articles/the-holy...teel-aluminum-
1423528185



Seems to be behind a pay wall.

Sounds interesting.

Try this:

http://www.digitalweldingsolutions.com/CMT.pdf

Fronius has been doing it for a while. It's welding on the aluminum
side, and brazing on the steel side.

To get at a WSJ article, or an Economist article (both behind pay
walls) copy the exact title and paste it into Google. Then click on
the hit that links to the publication.

For the WSJ article, try:

The Holy Grail of Welding: Steel + Aluminum

It usually works.

--
Ed Huntress

On Sun, 15 Feb 2015 21:55:46 -0500, Ecnerwal
wrote:

The ignorance of the news media is astounding.

Steel welded to aluminum was achieved on a commercially successful basis
years (probably decades) ago by the high energy materials folks - ie,
explosive welding. As far as I recall they simply made long strips of
interface welded explosively, and those were welded by normal means to
put aluminum superstructures on top of steel hulls.

Here's one, there are others: http://triplate.com

Yeah, but this is different. Fronius has been doing it. It really
could be important in car manufacturing.

--
Ed Huntress

Ecnerwal wrote:
The ignorance of the news media is astounding.

Steel welded to aluminum was achieved on a commercially successful basis
years (probably decades) ago by the high energy materials folks - ie,
explosive welding. As far as I recall they simply made long strips of
interface welded explosively, and those were welded by normal means to
put aluminum superstructures on top of steel hulls.

Here's one, there are others: http://triplate.com

All-Clad pots, pans and skillets are also layers of bonded steel and
aluminum. Somewhere there was a video of how the fuse everything into a
sheet. It's fascinating that this material can then be made into deep
pots.

On Mon, 16 Feb 2015 17:49:57 +0000 (UTC), Cydrome Leader
wrote:

Ecnerwal wrote:
The ignorance of the news media is astounding.

Steel welded to aluminum was achieved on a commercially successful basis
years (probably decades) ago by the high energy materials folks - ie,
explosive welding. As far as I recall they simply made long strips of
interface welded explosively, and those were welded by normal means to
put aluminum superstructures on top of steel hulls.

Here's one, there are others: http://triplate.com

All-Clad pots, pans and skillets are also layers of bonded steel and
aluminum. Somewhere there was a video of how the fuse everything into a
sheet. It's fascinating that this material can then be made into deep
pots.

Bonding aluminum and steel (including stainless) has been around since
the '60s. In the late '70s, roll bonding became a high-volume process
used to make automobile trim, including bumpers.

They get a strong bond that way, but it's not like these weld/braze
methods that are being used to make hybrid parts. This is fairly new.

The language used to describe it is all over the map, which is not
made clearer by the people trying to market it, nor by the
general-press writers trying to write about it.

--
Ed huntress