基于离散元法的涂层硬质合金刀具建模及其加工损伤预测

Modeling and damage prediction of coated carbide tool in cutting process based on discrete element method

首先建立了TiCN涂层硬质合金刀具基体材料(WC)的离散元模型,根据单轴压缩、三点弯曲以及断裂韧性等数值试验方法校准了基体材料离散元模型的微观参数,然后采用划痕法校准了基体与涂层的界面结合强度。根据Merchant切削模型,建立了涂层刀具切削过程中的刀-屑接触模型,通过对切屑施加周期性边界条件来模拟实际的切削加工过程;模拟了涂层刀具加工过程中的裂纹扩展和破坏情况,并预测了切削加工用量对涂层裂纹扩展及破坏的影响。

In this paper,a discrete element model of WC matrix material which is the part of TiCN coated carbide tool was established.Base on numerical tests,such as uniaxial compression test,three point bending test and fracture toughness test,the microscopic parameters of matrix material in DEM model were calibrated.Then,starching test was used to calibrate the strength of interfacial bond between TiCN coating and WC matrix.According to the Merchant’s cutting model,a tool-chip contact model was estab-lished.By applying a periodic boundary to tool-chip contact model,several different conditions of cutting processes were carried out to investigate the crack’s propagation and damage of coated carbide tool,and the influence of cutting parameters to the coated carbide tool’s crack propagation and damage were also predicted.