钛合金振动辅助热摆动辗压成形机理及摆辗性能研究

The replacement of the traditional tenon/mortise structural disk of compressor by the integral disk can effectively reduce the weight and consumption and improve the aerodynamic and reliability of the aero-engine. However, the great deformation resistance, poor fluidity and sensitive forming property to temperature and strain rate of titanium alloy result in the manufacture of the integral disk difficult. The vibration assisted hot rotary forging can reduce the forming force, improve the formability of the material and the capability of die filling. It is an effective technology for forming difficult-to-deform metal parts. In this project, the titanium alloy will be formed by the technology of vibration assisted hot rotary forging. The project mainly focuses on material behavior and rotary forging property of the titanium, as well as functional mechanism of vibration during vibration assisted hot rotary forging. Research on the rheology mechanism of titanium alloy during high temperature vibration compression and vibration assisted hot rotary forging to illustrate the rheological instability mechanism and the law of microstructure evolution. And reveal the activation mechanism of vibration on dislocation, phase transition and recrystallization as well as the evolution processing. Research on the response between rheological instability and rotary forging defects in vibration assisted hot rotary forging of titanium alloy to reveal the formation mechanism of rotary forging defects and its property. And obtain the matching and control method of process parameters of vibration assisted hot forging of titanium alloy. It can provide the theoretical basis and technical reserve for vibration assisted hot rotary forging forming technology of the integral disk in the both high-level technique field of aerospace engine and traditional industrial field of automobile.

压气机整体盘类件替代原有榫槽结构盘类件可使航空发动机有效减重降耗、提高气动性和可靠性。但钛合金变形抗力大、流动性差、成形性能对温度及应变速率敏感，制备困难。振动辅助热摆动辗压可降低成形力、提高材料成形性和模具填充性，是成形难变形金属件的有效方法。项目以钛合金为材料、以摆动辗压技术为基础，引入振动与热，重点研究钛合金在振动及高温下的材料行为和摆辗性能及振动作用机制。通过研究钛合金高温振动压缩及振动辅助摆辗过程中材料流变机理，阐明钛合金流变失稳机制及微观组织演变规律，探明振动对位错、相变及再结晶的激活机制以及演化过程的作用机制，研究钛合金振动辅助热摆辗过程中流变失稳与摆辗缺陷之间的响应，揭示摆辗缺陷形成机理及摆辗性能，获得钛合金振动辅助热摆辗工艺参数匹配与控制方法，为航空航天发动机等高端技术领域及汽车等传统技术领域整体盘类件的振动辅助热摆动辗压成形技术提供理论基础及技术储备。

本项目以扩大摆辗工艺对材料的适应范围及提高钛合金摆辗性能为目的，瞄准能提高航空航天飞行器用发动机性能的整体叶盘件、整体盘轴件的绿色、低成本、高性能制备，综合振动对塑性成形的作用机制、热加工优点及具有连续局部塑性成形特点的摆辗成形工艺，形成可有效成形难变形金属的振动辅助热塑性成形新工艺，项目以摆辗成形的应变分析、成形原理分析为基础，对摆辗工艺中摆头与工件的接触面积、材料的应变速率模型、材料的流动模型等理论进行了研究；通过有限元模拟，分析了成形过程中的应力应变分布对工艺参数及热力参数的响应，获得了振动辅助热成形的共性成形机理；以TC11钛合金为研究对象，研究了其在热处理、振动辅助热压缩及振动辅助热摆辗过程中的组织演变，揭示了振动对组织演变的作用机制；研究了在振动及热共同作用下钛合金的材料行为，揭示了在具有多场耦合及连续不均匀塑性成形特点的摆辗成形过程中，振动对材料流动、摩擦分布及成形件形状的作用机制，探查了钛合金振动辅助热摆辗成形过程中的损伤机制及塑性失稳机理，揭示了钛合金振动辅助热摆辗成形机理及摆辗性能，为采用振动辅助热摆辗制备具有难变形特点的钛合金零部件提供理论基础与技术支撑。