Study on collective friction and wear behavior of W-Ni-Fe alloy balls

Abstract Tungsten alloy balls are considered as one of the important candidate spallation targets for China initiative Accelerator Driven Subcritical System. The wear of these balls in the spallation target loop greatly affects their service life. In this work, the collective friction and wear of the balls at 250 °C were studied by using our self-developed equipment. The results reveal that the mass loss ratio of balls first rises and then falls, experiencing different stages, and its maximum is about 0.32 wt%. For each stage balls have their own unique wear characteristics. In the end a new layer with a structure of amorphous surrounding nanocrystallines is formed on the ball surface. The role of wear debris in the all process is discussed.