Fine finishing of tungsten alloy is required to improve the surface quality of molds and precision instruments. Nevertheless, it is difficult to obtain high-quality surfaces as a result of grain boundary steps attributed to differences in properties of two-phase microstructures. This paper presents a theoretical and experimental investigation on chemical mechanical polishing of W–Ni–Fe alloy. The mechanism of the boundary step generation is illustrated and a model of grain boundary step formation is proposed. The mechanism reveals the effects of mechanical and chemical actions in both surface roughness and material removal. The model was verified by the experiments and the results show that appropriately balancing the mechanical and chemical effects restrains the generation of boundary steps and leads to a fine surface quality with a high removal rate by citric acid-based slurry.

需要对钨合金进行精加工，以提高模具和精密仪器的表面质量。然而，由于两相显微组织性能差异导致的晶界台阶，很难获得高质量的表面。本文介绍了 W-Ni-Fe 合金化学机械抛光的理论和实验研究。说明了边界台阶的产生机制，并提出了晶界台阶形成的模型。该机制揭示了机械和化学作用对表面粗糙度和材料去除的影响。