【作者】 刘君；

【导师】 刘郁丽；

【作者基本信息】 西北工业大学 ， 材料加工工程， 2004， 硕士

【摘要】 叶片是航空工业中一类量大面广的重要零件之一。叶片精锻过程是一个受诸多因素影响的复杂变形过程，在叶片精锻过程中变形、传热和微观组织演变之间存在着复杂的交互作用。微观组织在很大程度上决定了叶片的质量和宏观机械性能，预测和控制叶片的微观组织，对提高叶片的综合机械性能具有重要的现实意义。为此本文采用能反映微观组织演变对材料流动应力影响的本构关系和Yada形式的微观组织预测模型，实现TC4钛合金叶片精锻过程的有限元变形—传热—微观组织演变耦合分析，为合理确定叶片精锻工艺和控制叶片质量提供依据。本文的主要研究内容和结果如下： 对TC4钛合金叶片精锻过程的有限元变形—传热—微观组织演变耦合分析的关键技术问题处理方法进行了研究，在此基础上，以本实验室开发的3D-CTM系统为平台，发展了叶片精锻过程的三维刚粘塑性有限元变形—传热—微观组织演变耦合分析系统3D-CDHTM(3-Dimensional Coupled Analysis of Deformation-Heat Transfer-Microstructure Evolution)。 利用3D-CDHTM系统对TC4钛合金单榫头叶片精锻过程进行了三维有限元模拟分析，获得了不同变形阶段下典型截面的网格图和等效应力、等效应变、等效应变速率、温度场的等值线分布图，从而揭示了单榫头叶片精锻成形规律。 对TC4钛合金叶片在不同变形温度、变形速度、模具温度和摩擦条件下精锻成形时的微观组织(晶粒尺寸和体积分数)进行了预测，全面系统地分析了不同变形工艺参数对微观组织的影响。并分析了不同变形工艺参数对载荷—行程曲线的影响。更多还原

【Abstract】 A blade is one of the most important mechanical components in aviation industry. Precision forging process of blade is a complex process with multi-factor effects. There’s complicated relationship between deformation, heat transfer and microstructure evolution in blade forging process. Quality and macro-mechanical properties of parts largely depends on microstructure. It is important to predict and control the microstructure of the blade for improving over-all mechanical properties. Therefore, in this paper, coupling analysis of deformation-heat transfer-microstructure evolution based on finite element method in TC4 blade precision forging process is carried out, using constitutive equation reflecting microstructure evolution influence on flow stress and Yada prediction model of microstructure evolution, and serve on the determination of process parameters and control of blade quality. A brief introduction to the project and its main results are as follows:The key technical problems of coupled FEM deformation-heat transfer -microstructure evolution in TC4 blade precision forging process are studied. Based on the developed 3D-CTM system, 3D-CDHTM (3-Dimensional Coupled Analysis of 3-Deformation-Heat Transfer-microstructure evolution) is developed.By using the 3D-CDHTM system, FEM analysis of precision forging process of TC4 blade with tenon was carried out. And the results have been obtained for deformed mesh, equivalent stress field, equivalent strain field, equivalent strain rate, temperature field at various deformation degrees of typical sections and the laws of the blade precision forging is revealed.Microstructure (grain size and volume fraction) of TC4 blade are predicted under various deformation temperature, velocity, die temperature and friction factor and the influence of deformation parameters on microstructure is studied and analyzed thoroughly and systematical. Meanwhile, the influence of various deformation parameters on load-stroke curve is analyzed.更多还原