×
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

ultrasonic welding of contaminated parts

ultrasonic welding of contaminated parts

ultrasonic welding of contaminated parts

(OP)
Hello all,

In one of our applications, we attach the "metal-graphite brushes" to the "brass terminals" by ultrasonically welding the brush shunts (or pig tail - made of copper braided strands) to the terminals.

This is being a bottle neck operation, because we are having repeated instances... where we couldn't weld the brush braids to the terminals consistently.

After a careful analysis of this problem, we found out that, there are a considerable amount of brushes whose pigtails are contaminated with brush dust.

As with the ultrasonic welding machine… the parameters (energy level, power & amplitude of vibration) were customized for the copper braids /pigtail. So, while using the contaminated pigtails, the machine couldn’t weld it because the energy level required welding it changes due to the inclusion of brush dust.

FYI. We nuggatize the end of the pigtails using resistance-welding to bundleup the braids to ease the assembly process. The speculation at this point is that the brush dust gets deposited in the pigtails and is embedded into it during the resistance welding. So during the actual ultrasonic welding process, the energy it takes to complete the weld increases because of the contamination. Then, when we increased the weld energy, though it gave us a good weld on the contaminated pigtails... but when the brushes with good pigtails were used, it over-welds it... resulting in a fracture at the transition.

(1) How to set the parameters, so that it would work for both (good and contaminated pigtails).
(2) Have anyone experienced a failure in the ultrasonic metal weld process do to the contamination? If so, how did you overcome it?
Also, kindly shed me some light on the different parameters and how they are related during the welding operation.

Thanks in advance for being generous with your time and expertise.

bernie

RE: ultrasonic welding of contaminated parts

I am not familiar with ultrasonic welding at all, but I am a little bit familiar with ultrasonic cleaning.  Therefore I would recommend ultrasonic cleaning before ultrasonic welding.  

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