【作者】 张李骊；

【导师】 李付国；

【作者基本信息】 西北工业大学 ， 材料加工工程， 2004， 硕士

【摘要】 航空发动机上的涡轮盘、承力盘和涡轮叶片等重要零部件都采用钛合金或高温合金等航空难变形材料锻造而成，由于设计方法和生产方式的不足，材料锻后组织和性能不稳定、成品率低，因而造成人力和物力的极大浪费。 本文针对航空难变形材料的成形特点，以TC4钛合金为研究对象，以盘形件等温模锻后的组织和性能为控制目标，采用有限元数值模拟和虚拟试验相结合的办法，分析研究了航空难变形材料的等温成形过程，并在此基础上确立了以组织稳定性为目标的锻造热力参数控制模式与人工智能控制技术。主要成果和新见解如下： 1．在一种基于并联关系模型的TC4合金新型本构关系模型的基础上，采用数理统计学的原理，科学地分析并回归出了该合金盘形件等温模锻时的再结晶微观组织分布与变形工艺参数间的关系模型，从而为TC4合金等温模锻过程的优化提供了基础； 2．采用结合正交试验与有限元数值模拟技术的虚拟正交试验，以终锻件组织均匀性为目标，分析研究了TC4合金盘形件等温成形过程，获得了不同于传统锻造规范的优选工艺参数，为锻造工艺参数的制订与终锻件质量的改善提供了参考； 3．在虚拟正交优化试验结果的基础上，结合建立的回归模型，采用优化算法——单纯形法，对TC4合金盘形件等温成形锻造工艺参数进行进一步的优化处理，模拟结果表明优化效果显著，为TC4合金盘形件等温成形锻造工艺参数的优化过程提供了一条从虚拟正交试验—回归模型—优化设计的新的思路。 4．采用热力学模拟—微观模拟—计算机数值模拟综合集成技术，运用线性规划理论中的灵敏度分析方法，以终锻件组织稳定性为目标，对TC4合金盘形件等温成形锻造工艺的控制进行了分析与研究，采用三层控制策略的思路，总结出了一套在PID控制与灵敏度分析理论基础上的设计与控制一体化模式，从而为实现锻压过程的现代化适时控制提供了参考，在实际生产中具有非常明显的理论意义和工程应用前景。更多还原

【Abstract】 Some important parts of aero-engine, such as turbine disk, force bearing disk, turbine blades and so on, are made of aerial materials difficult to deformation, like titanium alloy or high-temperature alloy. However, due to the shortage of design methods and methods of production, as-forged microstructure and property of forgings are instability but also the rate of finished products is low, so that it is very waste of human forces and materials.Based on the system study of deformation characters of Ti-6Al-4V alloy and virtual orthogonal experiments, taking the as-forged microstructure and property of isothermal disk-forging as objective function, the die isothermal forming process and the integrated technology of design and control of Ti-6Al-4V alloy in isothermal forming process have been analyzed with thermodynamic coupled FEM numerical simulation. The main research findings and new outlooks are as follows:(1) Based on a new constitutive equation of parallel model and mathematic theory of statistics, the relationship of as-forged recrystal microstructure distribution and technological parameters of forging was developed, providing a scientific basis for the optimum design of isothermal forming process of Ti-6A1-4V alloy.(2) Taking the as-forged microstructure uniformity as optimum objective function, the die isothermal forming process of Ti-6Al-4V alloy has been analyzed with the virtual orthogonal experiment that combined with FEM numerical simulation and orthogonal experiment, then its technological parameters was optimizing that is different with traditional ones, therefore, it provided a sound basis for the implemention of technological parameters and improvement of as-forged quality in forming process.(3) Based on the virtual orthogonal experiment results, technological parameters of Ti-6Al-4V alloy was further optimizing with regressive model and simplex method, a kind of optimizing algorithm, optimizing results have indicated that optimizing effect was obvious, then a new optimizing viewpoint that including virtual experiments, regression model and optimum design for technological parameters of Ti-6Al-4V alloy in isothermal forming process.(4) Based on an integrated method combined with thermodynamic simulation, microstructure simulation and computer numerical simulation and sensitivity analysis of linear program, taking the as-forged microstructure stability as control objective, the control of isothermal forming process of Ti-6Al-4V alloy was studied and with a three-layer control strategy, an new integrated technology of design and control based on PID control mode or sensitivity theory was proposed, thus,modernization updating control of forming process was realized, which has very obvious theoretical meaning and engineering application value in actual production.更多还原