Texture formation is frequently observed in parts produced by Laser Powder Bed Fusion(L-PBF),which can induce anisotropy and may potentially degrade plasticity.In this study,we introduce a laser remelt-ing strategy to...Texture formation is frequently observed in parts produced by Laser Powder Bed Fusion(L-PBF),which can induce anisotropy and may potentially degrade plasticity.In this study,we introduce a laser remelt-ing strategy to mitigate these adverse effects.By employing experimental observations and numerical simulations,we established the relationship between melt pool thermal history,variant selection,and mechanical properties.Our results indicate that the strengthening of texture can be prevented by dis-rupting the variant selection memory effect when there is a difference in scanning speeds between the printing and remelting lasers.The achieved random variant orientation is attributed to the altered cool-ing rates and temperature gradient directions during solidification across different layers.The optimized Ti-6Al-4V alloy demonstrates high strength(1211.5±13.3 MPa)and significant elongation(12.3%±0.8%),exhibiting a superior strength-ductility synergy compared to samples produced by direct printing or laser remelting with consistent parameters,as well as most reported L-PBF processed Ti-6Al-4V alloys.Our findings provide new insights into phase transformation kinetics in L-PBF of Ti-6Al-4V alloys and facilitate the Optimization of this process for manufacturing high-performance components.展开更多
基金the Key Basic and Applied Research Program of Guangdong Province(No.2022B1515120082)the National Natural Science Foundation of China(No.52371027)+2 种基金the Guangdong Science and Technology Innovation Project(No.2021TX06C111)the Guangdong Basic and Applied Basic Research Foundation(No.2022A1515012627)the Guangzhou Science and Plan Project(No.2024A04JB668).
文摘Texture formation is frequently observed in parts produced by Laser Powder Bed Fusion(L-PBF),which can induce anisotropy and may potentially degrade plasticity.In this study,we introduce a laser remelt-ing strategy to mitigate these adverse effects.By employing experimental observations and numerical simulations,we established the relationship between melt pool thermal history,variant selection,and mechanical properties.Our results indicate that the strengthening of texture can be prevented by dis-rupting the variant selection memory effect when there is a difference in scanning speeds between the printing and remelting lasers.The achieved random variant orientation is attributed to the altered cool-ing rates and temperature gradient directions during solidification across different layers.The optimized Ti-6Al-4V alloy demonstrates high strength(1211.5±13.3 MPa)and significant elongation(12.3%±0.8%),exhibiting a superior strength-ductility synergy compared to samples produced by direct printing or laser remelting with consistent parameters,as well as most reported L-PBF processed Ti-6Al-4V alloys.Our findings provide new insights into phase transformation kinetics in L-PBF of Ti-6Al-4V alloys and facilitate the Optimization of this process for manufacturing high-performance components.
