航空材料学报2026，Vol.46Issue(1)：60-69,10.DOI:10.11868/j.issn.1005-5053.2025.000068
扫描策略对激光选区熔化GH5188合金组织及力学性能的影响
Effect of scanning strategy on microstructure and mechanical properties of GH5188 alloy fabricated by laser powder bed fusion
摘要
Abstract
This study systematically investigates the effects of long-line and short-line scanning strategies on the microstructure and mechanical properties of GH5188 superalloy fabricated by laser powder bed fusion(LPBF).Metallography and SEM results reveal that both strategies produce mixed microstructures composed of columnar and equiaxed grains.Due to the shallower melt pool and insufficient remelting,the short-line strategy retains finer grains at the melt-pool center,leading to further grain refinement(17.17 μm).In contrast,the long-line strategy provides a more stable heat-flow direction,resulting in stronger<001>texture development along the build direction and a slightly larger average grain size(20.86 μm).Mechanical testing shows that the two strategies lead to similar tensile strength and ductility at room temperature.At 980℃,the tensile strengths are comparable,while the elongation of the long-line specimens is 28.6%higher than that of the short-line specimens.Under the 927℃/90 MPa stress rupture condition,the long-line specimens exhibit a significantly longer rupture life(50.2 h±1.8 h)and higher ductility(10.1%±0.5%)than the short-line specimens(45.3 h±2.1 h;7.6%±0.4%).Cross-sectional analysis shows that the short-line specimens contain more densely distributed cracks,along with pronounced carbide precipitation and coarsening at grain boundaries,indicating higher grain-boundary damage sensitivity.Fractographic analysis further confirms that cracks preferentially propagate along grain boundaries.These findings clarify the microstructural origins of high-temperature performance differences and provide guidance for optimizing LPBF scanning strategies for GH5188 alloy.关键词
激光选区熔化/钴基合金/扫描策略/力学性能/持久性能Key words
laser powder bed fusion(LPBF)/cobalt-based superalloy/scanning strategy/mechanical property/stress rupture property分类
航空航天引用本文复制引用
孙达,吴浩,宋长虹,朱玉平,谢君,梁静静,李金国..扫描策略对激光选区熔化GH5188合金组织及力学性能的影响[J].航空材料学报,2026,46(1):60-69,10.基金项目
辽宁省科技重大专项(2024JH1/11700038) （2024JH1/11700038）
国家重点研发计划(2023YFB3712003) （2023YFB3712003）
中国科学院青年创新促进会项目(2020198) （2020198）
