Eutectic high entropy alloys possess both excellent plasticity and high strength. To explore their potential engineering applications, the diffusion behavior of elements, the interfacial microstructure and shear strength of the diffusion bonded joint between AlCoCrFeNi_2.1 eutectic high entropy alloy and GH4169 superalloy were studied. The width of diffusion zone increased with bonding temperature increasing and the voids gradually disappeared due to the increased diffusion rate of the elements and the high-temperature creep. A new layer of face-center-cubic (FCC') phase, which was caused by the difference in diffusion rate of the elements between B2 phase and FCC phase in the eutectic high entropy alloy, generated in the diffusion zone and increased the shear strength of joints. The width of newly generated FCC' phase layer in front of the original FCC phase was wider than that in front of the B2 phase. The shear strength of the resultant joints increased and the fracture mode transformed from brittle fracture to ductile fracture with bonding temperature increasing. The maximum shear strength of 528 MPa was obtained and the dimples on fracture surfaces were found at the bonding temperature of 1050 °C.

共晶高熵合金具有出色的可塑性和高强度。为了探索其潜在的工程应用，AlCoCrFeNi _2.1之间的扩散键合元素的扩散行为，界面微观结构和剪切强度研究了共晶高熵合金和GH4169高温合金。扩散区的宽度随着键合温度的升高而增加，并且由于元素的扩散速率增加和高温蠕变，空隙逐渐消失。由共晶高熵合金中B2相和FCC相之间元素扩散速率的差异引起的新的面心立方（FCC'）相层在扩散区产生并提高了剪切强度关节。在原始FCC相前面的新生成的FCC'相层的宽度比B2相前面的宽度要宽。随着结合温度的升高，所得接头的剪切强度增加，断裂模式从脆性断裂转变为韧性断裂。