硬质合金刀具材料化学机械抛光机理研究

Chemical and Mechanical Polishing Mechanism of Cemented Carbide Tool Material

目的研究硬质合金刀具材料化学机械抛光(CMP)机理,为改善硬质合金刀具表面质量提供理论支持。方法分析硬质合金刀具材料在酸性抛光液中的化学反应,研究硬质合金刀具材料CMP的化学反应机理。基于接触力学理论计算抛光垫与工件的实际接触面积和单个磨粒的实际切削面积,在运动学分析的基础上,建立硬质合金刀具材料CMP的材料去除率模型,通过实验验证材料去除率模型的有效性。结果在酸性抛光液中,硬质合金被氧化成Co_3O_4。当工件、抛光垫、磨粒类型、工件安装位置确定时,材料去除率与抛光载荷、磨粒浓度和抛光盘转速有关。常用硬质合金抛光条件下,抛光YG8刀具的修正系数Kcm为8.53,抛光后刀具的最低表面粗糙度能达到48nm,材料去除率为62.381nm/min,材料去除率的理论值和实验值的最大相对误差为13.25%,消除了表面缺陷,获得了较好的镜面效果。结论建立的材料去除率模型具有一定的有效性,对硬质合金刀具材料进行化学机械抛光能消除刀具的表面缺陷,改善表面质量。

The work aims to study the chemical and mechanical polishing(CMP)mechanism of cemented carbide tool material,so as to provide theoretical support for improving the surface quality of cemented carbide tool.The chemical reaction of cemented carbide tool material in acid polishing solution was analyzed and the chemical reaction mechanism of cemented carbide tool material CMP was studied.The actual contact area between polishing pad and workpiece and the actual cutting area of a single abrasive particle were calculated based on contact mechanics theory,the material removal rate model of cemented carbide tool material CMP was established on the basis of kinematics analysis,and the effectiveness of the material removal rate model was verified by experiments.In acid polishing solution,cemented carbide tool was oxidized to Co3O4.When the workpiece,polishing pad,abrasive particle type and installation position were determined,the material removal rate was related to polishing load,abrasive particle concentration and polishing disc speed.The correction coefficient Kcmwas 8.53 for the YG8 tools CMP under common cemented carbide polishing conditions,and the lowest surface roughness of the polished tools could reach 48 nm.At this time,the material removal rate was 62.381 nm/min and the maximum relative error between the theoretical value and the experimental value of material removal rate was 13.25%.Thus,surface defects were eliminated and good mirror effect was obtained.The material removal rate model is effective certainly,and CMP of cemented carbide tool material can eliminate the surface defects of the tool and improve surface quality.