惯性导航关键件：加工工艺-力热载荷-表面微观结构及残余应力的演变及其预测模型研究

The project takes the part machining surface residual stress control as the demand, and the function and evolution of the microstructure of the machining surface incorporating thermal-machanical loadings effects is the key point. The relationship models between the machining process and thermo-mechanical loading, thermo-mechanical loading and microstructure characteristic parameters of machined surface are constructed. Through the relations iteration, the prediction from machining process and parameters to the surface microstructure is realized. A prediction model between the microstructure based on the dynamic behavior of the material and surface residual stress is constructed. Based on the existing theory and empirical models, study the effect of the microstructure properties on the flow stress, strain and strain rate effects; Based on the calculation of microstructural characteristics and macro-structural properties characteristic parameters, such as flow stress, strain and strain rate, under different conditions, obtain the corresponding data and establish its mapping relationship by using computational intelligence methods. The effect of thermo-mechanical loading on the microstructure and its evolution and the transformation of the microstructure characteristics and the properties of the material anisotropy are the science problem. These are the scientific basis for the precise control of the residual stress in the process of high performance flexible joints.

本项目以高性能零件加工表面残余应力控制的关键需求为导向，以研究力热载荷对加工表面微观结构的作用及演化为切入点，构建加工工艺及参数对力热载荷、力热载荷对加工表面微观结构特征参量的关系模型，通过关系的迭代，实现加工工艺及参数对表面微观结构的预测。构建基于材料动态行为特性的微观结构和加工表面残余应力预测模型。基于现有理论及经验模型，通过不同工艺条件下微观结构特性与宏观结构特性特征参量的计算，获取对应的数据。采用计算智能方法，建立微观特性与宏观特性的转换关系。尝试在以上关系模型基础上，基于力热载荷与加工表面微观结构的相互作用机理，通过正反向循环迭代、平衡与整合，并结合实验，对加工工艺及参数对残余应力的预测模型进行修正。重点解决力热载荷对加工表面微观结构的作用及演变规律、材料各向异性的微观结构特性与宏观均一特性的转换等科学问题，为高性能挠性接头加工工艺及参数对残余应力的精确控制奠定科学基础。

以恒弹性合金钢整体式双平衡挠性接头的制造瓶颈为对象，基于本项目既定的研究目标、主要研究内容个关键突破等，开展了相关基础理论、研究方法等的研究，注重理论研究、仿真研究以及工程试验研究，重视三者之间的紧密结合和相互论证。全面完成了项目任务规定的内容，解决了微小零件、微细加工特征的精密加工难题，主要成果包括，研究并提出了考虑相变的微米级加工特征磨削力热模型及其计算方法；研究并揭示了工艺参数-力热载荷对磨削表面完整性指标的作用机理；特别是通过理论研究和工艺试验，揭示了细颈双侧磨削的残余应力叠加效应，提出了控制壁厚小于45μm细颈精密加工残余应力的非对称磨削工艺参数及其组合条件，提高了该类产品的加工质量、合格率，以及产品质量的长期稳定性；解决了恒弹性合金钢的整体式双平衡挠性接头精密制造瓶颈和自动化修磨难题。