Friction stir spot welding has been shown to be a viable method of joining ultra high strength steel (UHSS), both in terms of joint strength and process cycle time. However, the cost of tooling must be reasonable in order for this method to be adopted as an industrial process. Recently a new tool alloy has been developed, using a blend of PCBN and tungsten rhenium (W-Re) in order to improve the toughness of the tool. Wear testing results are presented for two of these alloys: one with a composition of 60% PCBN and 40% W-Re, and one with 70% PCBN and 30% W-Re. The sheet material used for all wear testing was 1.4 mm DP 980. Lap shear testing was used to show the relationship between tool wear and joint strength. The Q70 tool provided the best combination of wear resistance and joint strength.
Revised: October 4, 2011 |
Published: September 14, 2011
Citation
Miles M., C. Ridges, Y. Hovanski, J. Peterson, M.L. Santella, and R. Steel. 2011.Impact of tool wear on joint strength in friction stir spot welding of DP 980 steel.Science and Technology of Welding and Joining 16, no. 7:642-647.PNNL-SA-79756.doi:10.1179/1362171811Y.0000000047