面向高速切削的钛合金Ti-6Al-4V动态本构模型:综述

Dynamic constitutive model of titanium alloy Ti-6Al-4V for high speed cutting:a review

高速切削是实现钛合金等难加工材料高效、高质量加工的有效技术方法。钛合金高速切削加工过程具有高温、高应变和高应变率的热力强耦合非线性动态特征。为了准确描述高速切削时钛合金动态力学行为,对钛合金动态本构模型的研究进行综述。以钛合金Ti-6Al-4V为研究对象,从唯象模型和物理学模型的角度,分析了Johnson-Cook模型、Zerilli-Armstrong模型、Bammann模型的适用条件及优缺点。经综合比较,选取Johnson-Cook模型开展进一步探究,并且基于温度影响和竞争机制影响对Johnson-Cook修正模型进行分类,Johnson-Cook修正模型的预测精度与经典模型的预测精度相比均有所提高;同时提出可将构建唯象-物理学复合本构模型作为探究钛合金动态本构模型的重点方向,采取实验与计算机同步方法得到本构模型参数的最优解,从而提高动态本构模型的预测精度。

High speed cutting is an effective technique to achieve high efficiency and high quality machining of titanium alloy and other difficult materials.The high speed cutting process of titanium alloy has the nonlinear dynamic characteristics of high temperature,high strain and high strain rate.In order to accurately describe the dynamic mechanical behavior of titanium alloy in high speed cutting,the research on dynamic constitutive model of titanium alloy is reviewed.The application conditions,advantages and disadvantages of Johnson-Cook model,Zerilli-Armstrong model and Bammann model are analyzed from the perspective of phenomenological model and physical model with Ti-6Al-4V as the research object.After comprehensive comparison,the Johnson-Cook model is selected for further exploration,and the Johnson-Cook modified model is classified based on the influence of temperature and competition mechanism.The prediction accuracy of the Johnson-Cook modified model is improved compared with that of the classical model.At the same time,it is proposed that the construction of phenomenology-physics composite constitutive model can be taken as the key direction to explore the dynamic constitutive model of titanium alloy,and the method of experiment and computer synchronization can be used to obtain the optimal solution of constitutive model parameters,so as to improve the prediction accuracy of dynamic constitutive model.