Microgrinding characteristics of Zr-based bulk metallic glasses

Abstract

The microgrinding experiments of Zr-based bulk metallic glasses (Zr-based BMGs) were conducted by using a JX-1A ultraprecision grinding lathe. The grinding force ratio, surface roughness, and material removal mechanism in microgrinding for Zr-based BMGs were investigated. The experimental results indicated that the grinding force ratio was 1.74~4.12. The microgrinding force and surface roughness value decreased with the increase of the spindle speed. The microgrinding force increased with the increase of the grinding depth, and the surface roughness value decreased first with the grinding depth increasing from 2 to 6 μm and then increased with the grinding depth increasing from 6 to 10 μm. The microgrinding force and surface roughness value increased with the increase of workpiece feed rate. On the basis of simple single-factor tests, the modified empirical mathematical model of the microgrinding surface roughness for Zr-based BMG was established, and the theoretical model of microgrinding force for Zr-based BMGs was verified. The best surface quality can be obtained when the grinding depth was 6 μm, the spindle speed was 6 × 104 r/min, and the workpiece feed rate was 20 μm. The microcracks and microholes were observed on the grinding surface generated by using diamond abrasive grinding tool. CBN abrasive 500# grinding tool with 0.9-mm diameter was considered to have better grinding performance. Compared with traditional crystal materials, Zr-based BMGs had good grindability. No light emission was observed in these experiments by daylight.