Optimization of resistance spot welding on the assembly of refractory alloy 50Mo–50Re thin sheet

Phase Change Effects on Transport Processes in Resistance Spot Welding

“…The direction of the columnar grains is always along the direction of heat flow during cooling. Since the cooling rate is the highest in the direction of electrode, it is common that the directions of columnar grains growing in these samples are roughly perpendicular to the welded sheet metal [5]. Similar microsturctures affected by thermal field in micro-resistance spot welding were presented by Zhou et al [6], Ely and Zhou [7], and Xu and Zhai [8].…”

“…Some pores were observed to occur on the edges of weld nugget, and large pores were in the center of weld zone in refractory alloy 50Mo-50Re (w t ) sheets, as presented by Xu et al [5]. The weld joints in alloys produced by powder metallurgy often contain voids produced by residual volatile materials.…”

“…The weld joints in alloys produced by powder metallurgy often contain voids produced by residual volatile materials. Aside from nucleation and growth of the bubble entrapped by solidification front [11], the large pores in the center of nugget might be also produced by metal expulsion upon welding [5]. Further work needs to be done to understand the mechanism for the formation of these large pores in the nugget.…”

Welding time effect on mechanical properties of automotive sheets in electrical resistance spot welding

“…Sun et al [10] has studied the microstructures and mechanical properties of resistance spot welded magnesium alloy joints. Xu et al [11] has made optimization of resistance spot welding on the assembly of thin sheets.…”

The small-scale resistance spot welding of refractory alloy 50Mo-50Re thin sheet

“…1 Because of their high melting points, however, the fusion welding of refractory alloys is diffi cult. To the knowledge of the authors, there are few reports on fusion welding of Mo-Re alloys in the open literature.…”