【摘要】 焊接热过程产生的组织及相变会改变材料的力学性能,使接头不同微区之间产生力学性能不均匀性,对接头的破坏行为有重要影响。为获得Ti₂AlNb基合金电子束焊接头不同区域的力学性能,采用纳米压痕技术,通过对压头压入材料表面过程的有限元模拟,建立了压痕响应与焊接接头材料本构关系参数之间的无量纲函数,构建了一种逆向获得材料微区弹塑性本构关系的新方法。基于该方法反演获得了Ti₂AlNb电子束焊接头不同微区的本构关系参数及其分布,分析了组织变化对接头微区性能的影响及接头的弱化区间。更多还原

【Abstract】 Microstructure transition resulted from the welding thermal process often changes the mechanical properties and induces heterogeneity of the materials of the joint,which affects the failure behavior of the joints significantly.In order to acquire mechanical properties over the region of EBW（electronic beam welding）joint of Ti₂AlNb alloy,a reverse methodology was proposed to constitute dimensionless functions to characterize the indentation responses and the constitutive relationship parameters,in which nano-indentation were conducted for Ti₂AlNb EBW joint and FEM（finite element analysis）simulation for indentation process were made.The constitutive relationship parameters and their distributions in different zones of the joints were acquired.The influence of the microstructure variation on the mechanical properties of different zones of the joint was analyzed and the weak zones of the joint were identified.更多还原