Effect of Friction Pair Materials on Friction and Wear Properties of TC4 Alloy

The friction and wear properties of TC4 alloy surface were investigated by ball/ plane contact form of TRB3 friction testing machine. TC4 ball, GCr15 steel ball and Si3N4 ceramic ball were used as the upper samples to study the friction scratches and wear characteristics of TC4 alloy under different normal forces. The friction scratch morphology was measured by 3D laser confocal microscope, and the energy wear models which could effectively predict the wear process were established to explore the change mechanism of contact state. The results indicate that the contact state of ball/plane changes to micro-plane/plane contact state with the decrease in the hardness of the upper sample. The length and width of friction scratches of TC4 alloy increase linearly with the increase in the load and the depth fluctuates like a "sawtooth" due to the effect of the dislocation wall of indenter front and the adhesion particles of indenter offside. The cutting to plasticity ratio (f(cp)) is distributed around both sides of f(cp)=0.5, indicating micro- ploughing and micro-cutting interact on the damage of TC4 alloy by indenter and the protective effect of process hardening phenomenon on the surface is verified. The linear relationship between scratch hardness and surface roughness could predict the damage during material deformation.