摘要
采用分子动力学方法建立了含有微缺陷的Ti2AlNb自扩散连接层的纳米板模型,研究了微裂纹和微孔洞等缺陷对Ti2AlNb扩散连接层力学性能及塑性变形特征的影响。结果表明:Ti2AlNb在纳米尺度下会出现两次屈服,第1次屈服应变约为0.04,第2次屈服应变约为0.11。微缺陷对屈服应力和第1次屈服时的屈服应变有明显的影响,屈服应变和屈服应力随着缺陷数量的增加而降低。含有微裂纹的Ti2AlNb的塑性变形机理为裂纹尖端钝化并转化为微孔洞,最终以孔洞长大的方式变形和失效。然而,在含有孔洞和微裂纹的Ti2AlNb中,孔洞由于受到[100]方向压应力的作用而聚合,裂纹在竖直方向的拉应力和水平方向的压应力的作用下,逐渐钝化成圆形微孔洞失效。
The nano-plate model of Ti2 Al Nb self-diffusion bonded layer with micro-defects was established by molecular dynamics method,the effects of micro-cracks and micro-voids on the mechanical properties and plasticity deformation characteristics of Ti2 Al Nb diffusion bonded layers. The results show that Ti2 Al Nb undergoes two yields at nanoscale,the first and the second yield strain are about 0. 04 and0. 11,respectively. The micro-defect has great influence on the yield stress as well as the yield strain at the first yield,and the yield strain and the yield stress decrease as the number of defects increases. The plastic deformation mechanism of Ti2 Al Nb with micro-cracks is that the crack tip is passivated and converted into micro-voids,which eventually deform and fail in the way of void growth. Voids in Ti2 Al Nb containing voids and micro-cracks are polymerized due to the compressive stress in [100]direction,and the cracks are gradually passivated into circular micro-voids failure due to the combined effect of the tensile stress in vertical direction and the compressive stress in horizontal direction.
作者
王斌
韩雅环
朱冬妹
刘太盈
王瑞
马向宇
WANG Bin;HAN Ya-huan;ZHU Dong-mei;LIU Tai-ying;WANG Rui;MA Xiang-yu(Beijing Xinghang Electro-Mechnical Equipment Co.,Ltd.,Beijing 100074,China;The Third Military Representative Office of the Navy in Beijing,Beijing 100074,China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2020年第11期202-209,共8页
Journal of Plasticity Engineering
关键词
微缺陷
TI2ALNB
扩散连接
力学性能
微观机理
micro-defect
Ti2AlNb
diffusion bonding
mechanical properties
microscopic mechanism
