Deformation Behavior of Zr-Based Metallic Glass and Microforming of Microgears

The deformation behavior of the Zr41.2Ti13.8Cu12.5Ni10Be22.5 bulk metallic glass (Vit1) in the supercooled liquid region was investigated. The stress-strain relations for Vit1 at the different specimen sizes were established in a uniaxial compression test using the microforming system. Furthermore, the effects of forming time, temperature and punch velocity on the flow stress of the specimen with a typical size of Φ1×1.5 mm were analyzed. The results indicate that Vit1 has excellent superplastic microformability at minimum forming time, higher temperature and lower punch velocity. Based on the research, Vit1 microgears with reference diameter of Φ1 mm and modulus of 0.1 mm were manufactured using the closed die forging. Optimum processing parameters were obtained. In order to evaluate the quality of Vit1 microgears, scanning electron microscope, atomic force microscope and nanoindentation tests were applied. It is found that the parts with good qualities can be formed successfully in the supercooled liquid region.