Shape controlling and property optimization of TA32 titanium alloy thin-walled part prepared by hot forming  

热成形TA32钛合金薄壁件的形状控制与性能优化

作　　者：Yong WU Rong-lei FAN Zhong-huan QIN Ming-he CHEN 武永;范荣磊;秦中环;陈明和(南京航空航天大学机电学院,南京210016;北京航星机器制造有限公司,北京100013)

机构地区：[1]College of Mechanical and Electrical Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China [2]Beijing Hangxing Machinery Manufacturing Co.,Ltd.,Beijing 100013,China

出　　处：《Transactions of Nonferrous Metals Society of China》2021年第8期2336-2357,共22页中国有色金属学报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(No.51805256)。

摘　　要：The hot flow behaviors,microstructure evolution and fractographs were studied to optimize the hot forming process of the TA32 titanium alloy thin-walled part.A set of microstructure-based constitutive equations were developed based on the experimental data,which described the relationships among the hot flow stresses and the evolution of phase volume fraction,dislocation density,grain size and damage.The constitutive model was imported into ABAQUS 6.14 to simulate the hot forming process for a typical thin-walled part.The effective strain,dislocation density and damage distribution as well as forming defects of formed parts under different process parameters were predicted.A qualified part without wrinkling and fracture defects was produced at a loading speed of 5 mm/s at 800℃ by the modified blank shape,where the maximum damage value was only 18.3%.The accuracy of constitutive model and finite element(FE)simulation was verified by the microhardness tests,which indicates that the FE model based on physical internal-state variables can well optimize the hot forming process of TA32 titanium alloy complex parts.为了优化TA32钛合金薄壁件的热成形工艺,对其热流动行为、显微组织演变和断口形貌进行研究。根据实验数据建立一套基于合金显微组织的本构方程,描述高温流动应力与相体积分数、位错密度、晶粒尺寸和损伤演化之间的关系。将本构模型嵌入ABAQUS6.14中模拟典型薄壁件的热成形过程,预测不同工艺参数下成形件的等效应变、位错密度、损伤分布以及成形缺陷。在变形温度为800℃、加载速度为5mm/s的条件下,采用改进形状尺寸后的毛坯成功模拟出无起皱和破裂缺陷的合格零件,且其最大损伤值仅为18.3%。通过显微硬度实验验证本构模型和有限元模拟的准确性,表明基于物理内变量的有限元模型能够有效地优化TA32钛合金复杂零件的热成形过程。

关 键 词：TA32 titanium alloy constitutive equation hot deformation microstructure evolution finite element method 

分 类 号：TG146.23[一般工业技术—材料科学与工程]