Solidification microstructure and residual stress correlations in direct energy deposited type 316L stainless steel
Solidification microstructure and residual stress correlations in direct energy deposited type 316L stainless steel
复制标题
直接能量沉积型 316L 不锈钢凝固组织与残余应力的关系
DOI：
10.1016/j.matdes.2021.109782
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发表时间：
2021
影响因子：
8.4
通讯作者：
Guo D
中科院分区：
文献类型：
--
作者：
Guo D
利用高能同步辐射X射线衍射技术，研究了316L不锈钢薄板直接能量沉积后残余应力分布的局部波动。宏观残余应力水平根据特征冷却速率在制品上稳定地变化，如所测量的枝晶臂长度所暗示的。在500和600 μm之间的长度尺度上的残余应力的局部波动与直接能量沉积期间形成的凝固微观结构的形态变化很好地吻合。计算表明，相关的介观热梯度波动沿着移动的熔池的凝固前沿的更大的倾向。通过考虑实验结果，分析了跨多个长度尺度的残余应力及其与金属增材制造中凝固微观结构形成的相关性的新观点。
Localised fluctuation in residual stress distribution for direct energy deposited 316L stainless steel thin plate was revealed through high-energy synchrotron X-ray diffraction. The macroscopic residual stress levels are changed steadily across the article according to the characteristic cooling rates, as implied by the measured dendrite arm lengths. Localised fluctuations of residual stress in the length scale, between 500 and 600 µm, coincides well with the morphological variations of the solidification microstructure that formed during direct energy deposition. Computations indicate a greater propensity for related mesoscopic thermal gradient fluctuations along the solidification front of the moving melt pool. Novel perspectives on residual stress across multiple length-scales and its relevance to the formation of solidification microstructure in metal additive manufacturing is analysed by considering the experimental results.