Crack initiation and mechanical properties of TC21 titanium alloy with equiaxed microstructure
Crack initiation and mechanical properties of TC21 titanium alloy with equiaxed microstructure
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DOI：
10.1016/j.msea.2013.08.012
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发表时间：
2013-12-01
期刊：
影响因子：
6.4
通讯作者：
Zeng, Weidong
中科院分区：
文献类型：
--
作者：
Shao, Hui;Zhao, Yongqing;Zeng, Weidong
利用扫描电镜（SEM）对等轴组织的变形和裂纹萌生进行了原位观察。当α（s）尺寸为0 μ m和0.1 μ m时，裂纹分别沿沿着α（p）/β和α/β（tr）边界（α（p），初生α相; β（tr），转变微观结构）开始。当粗化α（s）（α（s），二次α相）的尺寸为约0.5 μ m时，裂纹沿沿着α（p）/β和α（s）/（β）边界开始。结果表明，裂纹扩展是由于裂纹沿α（s）相的连续滑移而推迟的。α（s）的粗化导致合金塑性的增加，而对强度的影响很小。基于原位观察，通过热处理程序进一步优化粗化α（s）的形态。根据所进行的机械测试，可以看出，可以通过调整α（p）和α（s）相的尺寸和形态来获得最佳性能组合。(C)2013爱思唯尔有限公司版权所有。
Deformation and crack initiation of equiaxed microstructure were investigated using in-situ scanning electron microscopy (SEM). With alpha(s) sizes of 0 mu m and 0.1 pm, the cracks initiated along alpha(p)/beta and alpha/beta(tr) boundaries (alpha(p), primary alpha phase; beta(tr), transformation microstructure), respectively. When the size of coarsened alpha(s) (alpha(s), secondary alpha phase) was about 0.5 mu m, the crack initiated along alpha(p)/beta and alpha(s)/(beta) boundaries. The results show that the crack growth was put off by continuous slip across the coarsened alpha(s) phase. The coarsening of alpha(s) leads to increase in ductility of the alloy, while it has a slight effect on the strength. Based on the in-situ observations, the morphology of coarsened alpha(s) was further optimized by heat treatment procedure. According to mechanical tests performed, it was seen that the best property combination could be obtained by adjusting the sizes and morphologies of alpha(p) and alpha(s) phases. (C) 2013 Elsevier B.V. All rights reserved.