Effect of scan strategy on density and metallurgical properties of 17-4PH parts printed by Selective Laser Melting (SLM)
Effect of scan strategy on density and metallurgical properties of 17-4PH parts printed by Selective Laser Melting (SLM)
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DOI：
10.1016/j.jmatprotec.2017.06.023
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发表时间：
2017-11-01
影响因子：
6.3
通讯作者：
Brandt, M.
中科院分区：
文献类型：
--
作者：
Rashid, R.;Masood, S. H.;Brandt, M.
选择性激光熔化(SLM)是一种金属添加剂制造工艺，利用激光束逐层熔化和熔化金属粉末以制造零件。该技术涉及各种工艺参数的交互作用，如激光功率、扫描速度、粉层厚度和扫描策略。在本研究中，研究了两种不同的扫描策略对17-4PH不锈钢的影响，并对采用这两种扫描策略制备的17-4PH不锈钢样品的相对密度、显微组织相组成和显微硬度进行了表征。结果表明，采用双扫描策略打印的样品相对密度比采用单扫描策略打印的样品具有更高的密度。此外，还观察到采用双扫描策略制备的样品比采用单扫描策略打印的样品具有更高的硬度，这是由于这些样品中的马氏体相分布比残余奥氏体高。此外，预制样品的热处理产生了均匀分布的回火马氏体为主的相，残余奥氏体量很小，从而提高了硬度，与热处理的变形样品相当。
Selective Laser Melting (SLM) is a metal additive manufacturing process wherein a laser beam is used to melt and fuse metal powder layer by layer to create a part. This technique involves the interaction of various process parameters such as laser power, scanning speed, powder layer thickness and scan strategy. In this study, the effects of two different scan strategies were investigated and the 17-4PH stainless steel samples fabricated using these strategies, both in as-fabricated and heat-treated conditions, were characterized in terms of relative density, microstructural phase composition and micro-hardness. It was found that the samples printed with double scan strategy showed improvement in the relative density as compared to that printed with single scan strategy. Moreover, it was observed that the samples fabricated using the double scan strategy showed higher hardness than the samples printed using single scan strategy which was attributed to the high phase distribution of martensite than the retained austenite in these samples. In addition, the heat treatment of the as-fabricated samples produced uniform distribution of tempered martensite-dominant phase with negligible retained austenite, resulting in improved hardness as comparable to the heat-treated wrought sample.