Nanoscale precipitate in PBF-LB manufactured CoCrMoW alloy and its effect on passive behaviour

A CoCrMoW alloy with little carbon was manufactured through laser beam powder bed fusion technique. Nanoscale intermetallic Co-3(Mo,W)(2)Si precipitates uniformly dispersed on the gamma-Co phase matrix, and caused less segregation of Cr and Mo elements than the microscale carbides in the wrought CoCrMo alloy. Nanoindentation test results showed that the nano hardness of Co-3(Mo,W)(2)Si precipitate was 16.4 GPa, about 1.6 times of that of the matrix. The Volta potential of nanoscale Co-3(Mo,W)(2)Si precipitate was 14 mV more positive than the matrix. The corrosion resistance of the PBF-LB alloy in 0.9% NaCl solution was larger than that of the wrought alloy.

Automated summary

A low carbon CoCrMoW alloy was manufactured through laser beam powder bed fusion technique, with nanoscale intermetallic Co-3(Mo,W)(2)Si precipitates dispersed uniformly and showing improved corrosion resistance compared to the wrought alloy.