I am attempting to projection weld powder metal (iron + graphite) spacers (height of approx. 12 mm, with 3,3mm dia. projections)to 3 mm cold rolled steel stamping. I am having difficulties obtaining fusion. I am limited to how much force I can use because the projections will flatten prior to applying current. Seems 1200 lb works the best. I am limited to how much current I can apply because I cannot have any expulsion. I have tried a schedule of 14 cycles at 13,000 amps.... fusion was minimal. I then went to a weld schedule of 7 cycles at 16,000 amps and ran into expulsion issues with still minimal fusion. Has anyone had any success in projection welding such materials?

-- Chuck Woods (cwoods@wicometal.com), February 01, 2004