本立项涉及航空用GH4169镍基合金材料高温动态机械性能和材料切削过程实验研究以及相关的关键技术的研究，也涉及到相关基本理论框架和数值仿真技术的研究。基于改进的Hopkinson拉、压、扭杆材料动态加载实验技术及一级轻气炮材料动态性能高速加载技术，进行材料高温高应变率动态性能的实验研究和材料高速切削模拟实验研究。实验温度范围为20-1000℃，应变率为10^3-10^4 /s，切削速度范围是1-1000 m/s。在高速准微切削模拟实验过程中，将切削厚度的精度控制在微米量级。为描述材料正交切削过程，建立了描述材料二维切削过程的物理模型和相应的基本理论框架。该理论框架由无量纲主控参数、基本控制方程、多物理量渐进场以及判断材料塑性流动稳定性的普遍准则构成。数值模拟方面发展了基于耦合欧拉-拉格朗日表述的有限元模型。实现了振动切削、薄壁切削和实际车削过程的数值仿真计算。

This project involves experimental researches on the mechanical properties under the condition of high temperature and high strain rate and the machinability of nickel base super-alloy GH4169. The installations used in the experiments are the various Hopkinson Bar systems and one-lever light gas gun system. The ranges of experimental temperature and strain are 20-1000 oC and 103-104 1/s. The cutting speed is from 1 m/s to 1000 m/s. For analyzing the two-dimensional effects of chip flow, a basic theoretical framework under the plane strain loading condition is established for metal cutting. It includes a dimensionless governing equation system, a main dimensionless controlling parameter determined by experimental and numerical simulation, an asymptotic flow field obtained by approximate analysis of chip flow, and an instability criterion established by linear perturbation analysis. For the numerical analysis of metal cutting, an improved numerical model based on the coupled Eulerian-Lagrangian (CEL) formulation is proposed. In particular, the CEL model facilitates the simulations of some special cutting processes, such as the machining of a vibrating workpiece and a thin wall component.