Material Behavior in Micro Milling of Zirconium Based Bulk Metallic Glass

Bulk metallic glasses (BMGs) are a group of metallic materials with amorphous microstructure. BMGs have been increasingly used in various applications such as optical molds, sport equipment and biomedical components. The machining mechanism for the BMGs is distinct from that of the crystalline metal alloys due to the differences in their microstructures and mechanical properties. This paper presents experimental investigations on the material behavior in micro milling of zirconium based bulk metallic glass (Zr-based BMG). Micro milling of the BMG with high spindle speed up to 105,000 rpm was conducted. Surface morphology, microstructural evolution and crystallization of the machined surface were characterized by optical and scanning electron microscopy, X-Ray diffraction and energy dispersive X-Ray spectroscopy. The results detailed the responses of the Zr-BMG to the milling conditions which enables the machining conditions to be optimized to achieve an improved surface quality and machining efficiency.