文献类型：期刊文献

英文题名：Successfully prepared 316L parts with excellent performance and layer thickness exceeding 300 μm using laser powder bed technology with the assistance of thermal energy field coupling

作者：Chen, Bin[1];Zhang, Jianrui[1,2];Li, Bo[1,2]

机构：[1]East China Univ Sci & Technol, Sch Mech & Power Engn, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Addit Mfg & Intelligent Equipment Res Inst, Shanghai 200237, Peoples R China

年份：2025

卷号：156

起止页码：161

外文期刊名：JOURNAL OF MANUFACTURING PROCESSES

收录：;EI(收录号：20254719550266);WOS:【SCI-EXPANDED(收录号:WOS:001627057100002)】；

基金：The authors gratefully acknowledge that this research was funded by the Shanghai Explorer Program (Grant No. 24TS1411800), National Natural Science Foundation of China (Grant No. 52205155).

语种：英文

外文关键词：Laser powder bed fusion (LPBF); Thermal energy field assistance; Large layer thickness; Texture; Anisotropy

摘要：Large-layer-thickness Laser Powder Bed Fusion (LPBF) technology holds considerable promise for industrial applications due to its significant improvements in production efficiency. However, the increased layer thickness introduces challenges related to microdefects and the control of material organization, which must be addressed to fully harness its potential. This study aims to explore the impact of layer thicknesses exceeding 300 mu m on the microstructure and mechanical properties of 316 L stainless steel melt pools. By combining experimental investigations with Crystal Plasticity Finite Element Method (CPFEM) simulations, optimized LPBF process parameters were developed for layer thicknesses of 300 mu m, 400 mu m, and 500 mu m. The morphology, crystallographic texture, and grain boundary structure of the melt pool were characterized using optical microscopy (OM), scanning electron microscopy (SEM), and electron backscatter diffraction (EBSD), and their respective effects on mechanical properties were analyzed. The results demonstrate that increasing the layer thickness leads to grain coarsening and the strengthening of texture. At 300 mu m, a high relative density of 98.3 % and exceptional mechanical properties (ultimate tensile strength (UTS) = 777 MPa, elongation (EL) = 43.8 %) were achieved, surpassing the performance of thicker layer conditions. The tensile properties exhibited significant anisotropy, particularly in the transverse direction, where the dislocation density within the grains reached 1.9 x 1015 m-2, indicating both high strength and toughness. This study further elucidates the relationship between grain size, texture, and grain boundary distribution, as well as the temperature gradient (G) and cooling rate (C) under large-layer-thickness conditions. Moreover, the use of an external heating field for preheating the substrate and powder effectively reduced the initial thermal gradient between the melt pool and substrate. To address fusion defects typically observed in thicker layers, a lap rate control mechanism based on the width of the molten pool root is proposed. This mechanism prevents overheating and stress concentration caused by excessively high lap rates, thereby overcoming the technical bottleneck of density improvement under thick-layer conditions. Consequently, this approach enhances the industrial viability of additive manufacturing technologies.