Undeformed chip thickness models for precise vertical - spindle face grinding of tungsten heavy alloy

Abstract

Tungsten heavy alloys (WHAs) have superior usage performance in various applications and are expected to be used as key components in nuclear energy, aerospace and precision instruments. As a strain-rate sensitive material, the material properties of WHA will change greatly with different grinding parameters during processing. However, most of the existing material removal models are established based on the static properties of the material. The precision grinding of WHA still lacks theoretical guidance. In this research, the effects of strain, strain rate, and temperature on the dynamic properties of WHA under high temperature and high pressure during face grinding are considered. The maximum undeformed chip thickness model for vertical-spindle face grinding with cup wheels is established. The relationship between the undeformed chip thickness, grinding quality, and grinding parameters was investigated. Experimental results show that the maximum undeformed chip thickness under the same conditions is 3.16 times smaller than conventional grinding, and the critical strain rate for ductile-brittle transformation is about 1.46 × 107 s−1. The grinding specific energy of WHA decreases with the increase of the maximum undeformed chip thickness and decreases with the increase of the material removal rate, reaching a minimum of 121.6 J/mm3. This study not only provides a new method for predicting the grinding condition of WHAs but also enhances the understanding of the cup wheel face grinding process and provides theoretical guidance for reducing the machining damage of WHA.