Oxygen effects on glass formation of plasma arc sprayed Cu47Ti33Zr11Ni8Si1 surface coatings

A series of thermal spray experiments were performed to produce Cu47Ti33Zr11Ni8Si1 coatings from gas atomized powders synthesized with oxygen contents ranging from 0.125 to 0.79 wt.%. The amount of oxygen increased with decreasing particle size, which suggests the oxide is present as a surface film. Surface coatings were deposited using plasma arc spraying (PAS) in air and in an argon environment within an environmental chamber. The amount of amorphous phase was estimated for the gas atomized powders and plasma arc sprayed coatings. Despite the rapid solidification occurring during these two processing methods, substantial devitrification occurs in the high oxygen content powders and their associated coatings. Coatings deposited in air exhibit significantly more devitrification than their counterparts produced in the controlled environment chamber.