高速切削难加工材料刀—屑界面接触特性研究

Research on Contact Characteristics of Tool-Chip Interface of High Speed Cutting Difficult to Cut Materials

刀—屑接触长度和摩擦系数是表征刀—屑界面接触特性的主要物理量,直接影响切屑第二变形区切削热产量及刀具磨损。使用PCBN刀具正交车削GH3030高温合金和TC4钛合金,研究了两种材料的切削加工过程中刀—屑接触长度和刀—屑界面平均摩擦系数随切削速度和进给量的变化规律,分析了两种材料车削时摩擦系数和接触长度存在差异的原因。在高速切削下,建立了两种材料的刀—屑接触长度的直线和二次模型,发现TC4的二次模型能更好地预测接触长度,GH3030的直线模型和二次模型的相关系数相差不超过0.06。

Tool chip contact length and friction coefficient are important parameters that indicate the contact characteristics of tool-chip interface, as it directly affects the cutting heat production of the secondary deformation zone and tool wear. Using PCBN tools, superalloy GH3030 and titanium alloys TC4 were orthogonal cut. The tool-chip contact length and tool-chip interface average friction coefficient variation with cutting speed were investigated. Also, the reason why there was a gap between the contact lengths of two materials was analyzed. In high-speed cutting, the quadratic model and linear model of the contact length of the two materials were established. The result shows that the quadratic model of the TCA is better for prediction of contact length ,which can provide theoretical reference for finite element analysis and processing practices.