Understanding the friction and wear mechanisms of bulk metallic glass under contact sliding

This paper investigates the friction and wear properties of bulk metallic glass Ti40Zr25Ni3Cu12Be20 (at%) sliding against EN26 steel in a dry environment. It was found that frictional heating plays a central role in the variation of the tribological properties of the material. When the temperature rise does not cause phase transformation but introduces plasticity, the friction coefficient decreases and the wear rate increases. A further temperature rise brings about a wear mode transition from brittle to ductile wear. When the temperature is above the glass transition temperature of the material, crystal particles emerge in the deformed subsurface, and turns the wear to a brittle mode again, even though superplastic deformation of the material also takes place in conjunction with such phase transformation. As a result, friction coefficient increases and wear rate decreases.