【作者】 刘钢； 武永；

【Author】 Liu Gang;Wu Yong;Harbin Institute of Technology;

【机构】 哈尔滨工业大学；

【摘要】 Ti₂AlNb基合金具有优良的高温抗蠕变等性能,是650～750℃区间航空航天轻质结构材料之一。为了解决Ti₂AlNb基合金薄壁复杂曲面件尺寸精度及组织性能控制问题,建立了基于物理内变量的统一粘塑性本构方程,描述了板材在910～1000℃范围内的高温组织演变与高温流动应力的关系。基于该本构方程开发了ABAQUS平台的VUMAT材料模型,对Ti₂AlNb基合金杯形件成形进行有限元分析,并与实验结果对比。结果表明,基于物理内变量的统一粘塑性本构模型可以较好的预测相对位错密度和损伤演变,为Ti₂AlNb基合金曲面薄壁件热态气压成形工艺优化提供理论依据。更多还原

【Abstract】 Ti₂AlNb-based alloys are potential materials for long-time service at 650～750℃ for aerospace flights, resulting from its advantages of good creep resistance. To control the dimensional accuracy and mechanical properties of the complex shape Ti₂AlNb part, the uniform viscoplastic constitutive model of Ti₂AlNb alloy was set up to describe the relationship of microstructure evolution and flow stress in 910～1000℃. Meanwhile, the VUMAT model for ABAQUS was developed to simulate the hot gas forming of Ti₂AlNb cup-shaped part. The simulation and experimental results show that based on the uniform viscoplastic constitutive model, relative dislocation density and damage can be predicted, which provides the reference for the design of forming process for Ti₂AlNb complex-shape thin-walled parts.更多还原