Study On The Cutting Performance of High-Speed Machining Zr-Based Bulk Metallic Glass

Abstract

The cutting performance of high-speed machining (100-350 m/min) Zr57Cu20Al10Ni8Ti5 (at.%) bulk metallic glass (Zr57 BMG) was studied, as compared with industrial pure zirconium (Zr702). The effect of cutting speed on cutting force, surface roughness, surface morphology and chip morphology was analyzed. Although the strength of Zr57 BMG is much higher than that of Zr702, the difference in main cutting force is small, which can be attributed to the thermal softening of Zr57 BMG material during machining. The machined surface characteristics and the formation of chips were investigated. Different from low-speed machining, the groove marks and adhensions on machined surface evolve into wave patterns and molten droplets with the cutting speed increasing from 100 m/min to 350 m/min. The appearance of wave patterns tends to destroy the machined surfaces, and the worst quality was obtained at the speed of 250 m/min. The free surface morphology of the chips, with cutting speed smaller than 150 m/min, show obvious serration and molten droplets between shear bands. With the increase of cutting speed, oxidation on the chip surfaces occurred, and the chip surface was gradually covered by powder particles due to the melting of Zr57 BMG workpiece materials. The machined surfaces of Zr57 BMG maintain amorphous structures after high-speed machining, which shows excellent application potential for the processing of Zr57 BMG.