×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Pitting when resistance welding aluminum

Pitting when resistance welding aluminum

Pitting when resistance welding aluminum

(OP)
We have a application where we are resistance projection welding aluminum.  We are having problems at the ground electrode with pitting.  Our electrodes are RWMA class #3 copper.  Is there a different material that is better suited for this type of welding?  What other issues may be causing this?

RE: Pitting when resistance welding aluminum

Aluminum and aluminum alloys are not recommended for projection welding. Regular spot welding should be preferred where applicable.

http://www.welding-advisers.com/

RE: Pitting when resistance welding aluminum

(OP)
I have heard that, but do not know any details why it is not recommended. Projection welding was chosen because the process and the machine must be interchangeable with either steel or aluminum parts with minimal changeover.

Plus, we aren't having any problems with the weld.  The problem is in the ground electrode.  Aluminum is transferring to the ground electrode after only a dozen or so cycles.  These deposits are then causing damage to the surface.

RE: Pitting when resistance welding aluminum

The ASM Handbook Vol. 6 reports as follows:
..."Aluminum and aluminum alloys are very difficult to projection weld. The aluminum oxide is so tenacious that solid projection welding, in particular, is nearly impossible. In addition, it is very difficult to localize heat, because aluminum alloys soften at such low temperatures."
For resistance welding of aluminum the recommended material is RWMA Group A class 1 material. Effective electrode cooling is always needed.

http://www.welding-advisers.com/

RE: Pitting when resistance welding aluminum

Al has a great affinity for other elements such as Fe and Cu, and therefore sticking is problem.  The other reason for difficulty in localizing heat is due to the high thermal conductivity of Al.

RE: Pitting when resistance welding aluminum

Could you try a different current setting?

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources