Strategy of Residual Stress Determination on Selective Laser Melted Al Alloy Using XRD
Strategy of Residual Stress Determination on Selective Laser Melted Al Alloy Using XRD
复制标题
利用 XRD 测定选区激光熔化铝合金残余应力的策略
DOI：
10.3390/ma13020451
复制
发表时间：
2020-01-02
期刊：
影响因子：
3.4
通讯作者：
Wang, Haowei
中科院分区：
文献类型：
--
作者：
Chen, Yujiong;Sun, Hua;Wang, Haowei
已知选择性激光熔化（SLM）会在样品中产生较大的各向异性残余应力。精确测量SLM产生的样品上的残余应力对于理解SLM过程中残余应力积累机制至关重要，而在文献中报道的残余应力值中可以观察到剧烈的波动。在研究表面粗糙度对x射线衍射（XRD）测量残余应力影响的基础上，提出了一种由机械抛光和化学蚀刻组成的前处理耦合x射线衍射技术。结果表明，在高表面粗糙度的slm试样上，XRD测量的残余应力明显低于成品试样，这是由于试样尖刺表面的应力松弛造成的。系统地研究了slm法制备AlSi10Mg样品的表面残余应力分布和扫描策略的影响。在样品与建筑平台的界面处观察到微观结构形态，并与残余应力的表面分布有关。该方法可以帮助我们准确测量SLM生产样品中的残余应力，从而更好地了解其在SLM过程中的积累机制。
Selective laser melting (SLM) is known to generate large and anisotropic residual stresses in the samples. Accurate measurement of residual stresses on SLM-produced samples is essential for understanding the residual stress build-up mechanism during SLM, while a dramatic fluctuation can be observed in the residual stress values reported in the literature. On the basis of studying the influence of surface roughness on residual stress measured using X-ray diffraction (XRD), we propose a procedure coupling XRD technique with pretreatment consisting of mechanical polishing and chemical etching. The results highlight that residual stresses measured using XRD on as-built SLM-produced samples with high surface roughness are significantly lower than those measured on samples with finished surface, which is due to the stress relaxation on the spiked surface of as-built samples. Surface distribution of residual stresses and the effect of scanning strategy were systematically investigated for SLM-produced AlSi10Mg samples. Microstructural morphology was observed at the interface between sample and building platform and was linked to the surface distribution of residual stresses. This procedure can help us accurately measure the residual stresses in SLM-produced samples and thus better understand its build-up mechanism during the SLM process.