Forming quality control of Laser Powder Bed Fusion GH3536 alloy: Surface quality, defects, and microstructure

作者：Zhenyu Niu, Junfeng Zhang, F. Liu, Fencheng Liu, Fencheng Liu, Lixin Liu, Qifan You, Lixin Liu, Xuehao Gao, Jingyu Xu, Shuitao Zhou, Hao Qiu, Shuitao Zhou · 发表于：Materials Science in Additive Manufacturing · 年份：2025 · DOI：10.36922/msam025220042 · 被引用次数：8 · 研究领域：Additive Manufacturing Materials and Processes、High Entropy Alloys Studies、Surface Treatment and Coatings

This study investigates the influence of volume energy density (VED) on surface quality, density, defects, and microstructure of laser powder bed fusion (L-PBF) GH3536 alloy. Specimens fabricated below 80 J/mm3 exhibit lack-of-fusion pores on surfaces and internally, with pore density decreasing but crack initiation occurring as VED increases. Density consistently exceeds 99.5%, peaking at 99.85% (VED = 167 J/mm3). Excessive VED (208 J/mm3) induces surface warping, reduces cracking, but increases pore size/quantity, causing marginal density reduction. Lack-of-fusion defects nucleate microcracks distributed in layer bands; cracks propagate along high-angle grain boundaries following grain growth directions with significant localized stress. Higher VED increases melt pool overlap rate (70.49% at 208 J/mm3) and aspect ratio (width/depth = 6.9), while reducing cooling rates to 1.2 × 105 K/s.