An innovative laser welding strategy for B2-structured high-entropy intermetallic compound alloys

• Developed an innovative laser welding technique that achieves crack-free welding of high-entropy intermetallic compounds. • The Ni-Ti interlayer significantly enhances joint performance, demonstrating a 15.8 % improvement in tensile strength and 22.2 % improvement in elongation. • Multiscale computational modeling synergistically validated the Ni-Ti interlayer’s efficacy in mitigating thermally induced fracture propensity. • This work provides both a practical welding solution and basic insights into the microstructure and stress mechanisms in welding of high-entropy intermetallic compounds. High-entropy intermetallic compound alloy (HEIC) incorporates the advantages of high-entropy alloy (HEA) and intermetallic compound (IMC), rendering it promising structural materials for high-temperature applications. However, similar to traditional IMC, the welded joints of HEIC are prone to severe hot cracking tendencies and insufficient toughness. Therefore, there is an urgent need to optimize the welding process. Nevertheless, the evaluation of the weldability and joint properties of HEIC has remained a relatively under-researched area, lacking comprehensive investigation. This study primarily focuses on the welded joints of B2-structured TiZrHfFe 0.75 Co 0.75 Ni 0.75 Cu 0.75 HEIC. To achieve the goal of optimizing the comprehensive performance of the welded joints, a blue fiber delivered direct diode laser combined with fiber laser composite welding technology was employed, along with the addition of a Ni-Ti interlayer to refine the microstructure in weld zone. Experimental results demonstrate that this novel welding process significantly reduces cracking in the welded joints while improving joint tensile strength and elongation by 15.8 % and 22.2 %, respectively. Furthermore, computational simulations were conducted to investigate the influence of the interlayer on the microstructure and mechanical properties of the welded joints. The findings of this study provide valuable insights into the application of laser welding in HEICs.