堆积方向对激光选区熔化TC4合金缺口件局部循环塑性行为的影响

Influence of stacking direction on the local cyclic plastic behavior of selective laser melted TC4 alloy notched parts

通过数字图像相关技术从宏观塑性变形方面研究了堆积方向对激光选区熔化(SLM)TC4合金缺口件局部循环塑性行为的影响。结果表明:缺口附近的塑性变形受堆积方向和缺口半径的影响,进而影响缺口件的疲劳寿命。缺口根部的棘轮应变及其应变率随堆积方向改变(0°至90°)而降低,同时也随缺口半径的增加而降低。与缺口半径相比,棘轮应变及应变率和疲劳寿命对堆积方向敏感性更低。研究结果为SLM构件的疲劳设计提供了一定的理论参考。

In this paper the influence of stacking direction on the local cyclic plastic behavior of selective laser melted(SLM)TC4 alloy notched parts had been investigated through digital image correlation technology.The results indicate that the plastic deformation near the root of the notched parts can be influenced by the stacking direction and notch radius,thereby affecting the fatigue life of the notched parts.The ratcheting strain and strain rate near the root of the notch decrease with the change of stacking direction(from 0°to 90°),and also decrease with the change of the notch radius.Compared with effect by notch radius,stacking direction cause less influence on the ratchet strain,strain rate and fatigue life.The research results will provide a certain theoretical reference for the fatigue design of SLM parts.