Densification and microstructural investigation of Inconel 718 parts fabricated by selective laser melting
Densification and microstructural investigation of Inconel 718 parts fabricated by selective laser melting
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DOI：
10.1016/j.powtec.2017.01.030
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发表时间：
2017-04-01
影响因子：
5.2
通讯作者：
Yu, Ji-Hun
中科院分区：
文献类型：
--
作者：
Choi, Joon-Phil;Shin, Gi-Hun;Yu, Ji-Hun
研究了选择性激光熔凝(SLM)Inconel718零件在不同激光扫描速度下的致密化行为和组织演变。采用气体雾化法制备了Inconel718粉末的原料，粒度分布均匀，流动性好。在SLM过程中，扫描速度对致密化起决定性作用，当激光扫描速度为800 mm/S时，可获得最高的密度(~gt；99%)和硬度(320 Hv(0.5))。这些颗粒，特别是在XZ和YZ平面上，被观察到与建筑方向(Z轴)平行，尺寸从几微米到数百微米不等。研究还发现，在0.5-1微米的指定范围内，细小的胞状亚结构嵌入到每个具有小角度边界的大颗粒内(
In this study, the densification behavior and microstructural development of Inconel 718 parts fabricated by selective laser melting (SLM) were investigated with variation of the applied laser scanning speed. The starting materials of Inconel 718 powder particles were prepared using a gas atomization process showing uniform size distribution with high flowability. During the SLM process, the applied scan speed played a decisive role in densification during the SLM process, and that the highest density (>99%) and hardness (320 Hv(0.5)) could be achieved at the laser scanning speed of 800 mm/s. Upon fabrication, the microstructure of Inconel 718 parts was characterized by the presence of columnar grains, due to the rapid rate of cooling of the molten pool. These grains, in particular, in XZ and YZ planes, were observed to be parallel to the building direction (Z-axis), with size ranging from several to hundreds of micrometers. It was also found that the fine cellular substructures, within the specified range between 0.5 and 1 mu m, were embedded inside each large grain with low angle boundaries (