Wear resistivity of super-precision microgear made of Ni-based metallic glass

A microgeared motor with a diameter of 2.4 mm was constructed using a Ni-based (Ni53Nb20Ti10Zr8Co6Cu3, numbers indicate at.%) metallic glass (MG). The durability of the geared motor was improved due to superior wear resistivity of the MG. In order to clarify the superior wear resistivity of the Ni-based MG, simplified sliding-wear and rolling-wear tests were performed. The wear loss of the Ni-based MG under sliding-wear condition was larger than that of SK-steel, while the Ni-based MG exhibits superior wear resistance under rolling-wear condition. It is therefore concluded that better wear resistivity can be obtained under rolling condition which changes contact surface continuously. Wear mechanisms of MG and steel are compared and discussed.