The International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), under India's Department of Science and Technology, has successfully used laser powder bed fusion additive manufacturing (PBF-LB/M) to directly deposit stainless steel (SS316L) onto Inconel 718 substrates, producing crack-free, pore-free bimetallic interfaces. Microhardness testing revealed a peak of approximately 310 HV at the interface, with an ultimate tensile strength of 550 ± 30 MPa. Fracture occurred on the softer stainless steel side rather than at the joint, demonstrating excellent interfacial bonding. This technique overcomes issues such as solidification cracking and brittle phase formation caused by mismatches in chemical composition, melting point, and thermal expansion coefficient during conventional welding. It enables expensive superalloys to be used only in areas subjected to the highest thermal loads, reducing material costs and import dependency. Applications span aerospace, nuclear energy, ultra-supercritical thermal power plant boiler tubes, and heat exchangers.
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印度ARCI利用PBF-LB/M开发无裂纹双金属超合金结构,解决异种材料焊接难题
印度科学技术部下属国际粉末冶金与新材料高级研究中心(ARCI),利用激光粉末床熔融增材制造技术,成功将不锈钢(SS316L)直接沉积在Inconel 718基板上,制备出无裂纹、无孔隙的双金属界面。显微硬度测试界面处峰值约310 HV,极限抗拉强度550±30 MPa,断裂发生在较软的不锈钢一侧而非结合处,证明界面结合质量良好。该技术解决了传统焊接中因化学成分、熔点和热膨胀系数不匹配导致的凝固裂纹和脆性相问题。可将昂贵超合金仅用于承受最高热负荷的区域,降低材料成本与进口依赖,应用覆盖航空航天、核能、超超临界火电锅炉管和热交换器等领域。