|
|
Thread Tools | Search this Thread | Display Modes |
#1
|
|||
|
|||
GM prepping industry-first steel-to-aluminum welding process
Here is some recent news about a new GM spot welding process:
http://articles.sae.org/14838/ General Motors is poised to pull the trigger on a potentially game-changing manufacturing process to spot weld steel to aluminum. In the first production application for the patented process at GM’s Hamtramck, MI, assembly plant, the advanced spot welding eliminates rivets that join an aluminum bracket to a steel framework to form part of the seatback for the Cadillac CT6. Engineers claim GM’s steel-to-aluminum welding will be an industry first when it launches later this year. If all goes according to plan with the seatback frame, GM intends to expand the process to the hood of the CT6, a new flagship sedan that currently represents the company’s most aggressive use of multi-material construction. A specially-designed ridged electrode for the welding-gun tip is a key component of the system, said Blair Carlson, lightweight material processing lab group manager at GM Research & Development. In all, there are 19 patents covering hardware and controls for the process. The advanced electrode helps to alleviate the physical-properties issues that to now have stymied steel-to-aluminum welding, including the 900º C delta in melting points between the two materials, formation of oxides on the aluminum component that compromise weld integrity and the tendency for a “glassy” layer to form between the two disparate materials, causing brittleness of the weld. Carlson said cycle time before the welding-gun tip requires dressing currently is about 20 welds. The goal is to move the cycle into the hundreds—this as part of the GM research unit’s mandate for the new welding process to minimize added cost, enhance assembly-plant tooling flexibility for mixed-material vehicles and eventually eliminate altogether the need to rivet steel and aluminum. Once the mixed-material welding of the CT6 seatback is up to speed, engineers are eying the car’s hood with the intention of welding the pedestrian-impact steel reinforcement to the hood's aluminum “inner.” This will eliminate scores of rivets currently used to join the two pieces, Carlson said. Advanced joining techniques for the CT6, which employs 11 different materials in the body structure, already have eliminated more than 1400 rivets, which in aggregate add incremental weight and cost. GM estimates the new welding process could eliminate up to 10 lb (4.5 kg) of rivets on some vehicles. I recall we had some discussion in the past about welding steel and aluminum. I couldn't find that thread, but this will add to that topic.
__________________
Tom |
#2
|
||||
|
||||
It will be interesting to see the details on this process. Will probably be done with the stir welding process on a plated surface or with something between the two different metals. Won't be the standard type of spot welding.
__________________
Joe Hartson There is more than one way to go to town and they are all correct. |
#3
|
||||
|
||||
interesting i thought they glued a lot of joins these days it claimed to be stronger than a weld
__________________
David Geelong victoria Australia |
#4
|
|||
|
|||
Wow , I agree it’s an interesting idea but it’s sounding like another technology that body repair shops will not be able to duplicate out in the field. My gut feeling is if they do come up with a welder that can do it in body shops it’s going to be so expensive very few shops will be able to afford it but I hope I’m wrong. ~ John Buchtenkirch
__________________
John |
#5
|
||||
|
||||
as joe mentioned it probably will be the stir welding process - http://world.honda.com/news/2012/412...teel-Aluminum/ or something similar,
i also believe from what i read a couple of years ago that vw have done something (or have done testing) with something similar interesting none the less...
__________________
Neil |
#6
|
|||
|
|||
I'm having trouble understanding how this might work.
The Honda process is a continuous stir process, what I think of as friction stir welding, and the GM a "spot" process. One could certainly stir weld in one spot, but with a "ridged" electrode?
__________________
Neil Hochstedler |
#7
|
|||
|
|||
GM has filed for 19 new patents, so it could be a totally new process.
__________________
Tom |
#8
|
|||
|
|||
welding steel to aluminum
I agree, the GM process with be out of reach for most of us. However, transition metals have been used for years to weld dissimilar metals.
The transition metals are available but usually not in small quantities. http://spurind.com/products/dissimil...als-interface/ One possibility for DIY is to use a Stainless steel clad to aluminum fry pan. These are not cheap new, but an astute garage sale shopper may score one at a reasonable price.
__________________
Bill Funk |
#9
|
||||
|
||||
do a search on cold arc Welding...
Been around for years.
__________________
Nico |
#10
|
|||
|
|||
Presumably it's the spot welding thing that is new because the Brits have been welding steel to aluminium since WWII. The Germans used a lot of aluminium in their ship construction so they could claim lower tonnages and it was soon noticed that shell splinters would weld themselves on and wouldn't come off.
Strips of aluminium explosively-welded to steel have been used for many years to, for example, attach an aluminium superstructure to a steel hull by welding above and below the join and there's no electrolysis in the join. Will
__________________
Here to learn. William Pointer |
Thread Tools | Search this Thread |
Display Modes | |
|
|