刀-屑局部摩擦因数建模及实验研究

Modeling and Experimental Investigation on Local Friction Coefficient of Tool-Chip Contact Interface

基于黏着摩擦理论建立局部摩擦因数与接触面正应力和相对滑移速率之间的经验模型.采用试验方法来分析直角切削过程刀-屑接触面间的局部摩擦现象.设计的实验能够提供与实际切削相同的相对滑移速率和正应力条件.基于实验数据拟合并建立了基于正压力、相对滑移速率的摩擦因数经验模型.实验表明,在一定范围正应力和滑移速率下,摩擦因数随着接触面间的正应力、相对滑移速率的增加而降低.

Friction characteristics at the tool-chip contact interface is one of the two main factors affected predictions.The value of friction coefficient which represent contact interface frictional characteristic is difficult to determine due to contact interface in metal cutting involves several complex physical phenomena and it＇s not a constant parameter for the contact behavior is locally different.This paper aims to identify a friction model to describe the friction coefficient at this interface during the dry cutting based on the stick-slip friction theory.The experiment approach used could reach relevant values of pressures and sliding velocities.Investigations were conducted for quenched and tempered AISI1045 steel in combination with uncoated high speed steel tools.A new friction model has been identified based on normal stress and sliding velocities.The experimental analysis shows change in different degrees caused by the varying of normal stress and sliding velocities.