Diffusion bonding between TZM alloy and WRe alloy by spark plasma sintering

Solid-state diffusion bonding of TZM alloy to WRe alloy was performed using spark plasma sintering (SPS). The microstructure, mechanical properties and thermal fatigue of the TZM/WRe joint were investigated in detail. The results showed that successful solid-state diffusion bonding was achieved between TZM alloy and WRe alloy using SPS at temperature of 1 500 °C for 30 min. The TZM/WRe interface is free from discontinuities or microcracks. Recrystallization occurs in both the TZM alloy and WRe alloy during diffusion bonding. comparison with W and Re, the diffuse depth of Mo is greater than that of W and Re in the TZM alloy, due to its lower self-diffusion activation energy. The TZM/WRe joint shows excellent resistant ability to thermal shock and part of Mo grains grow through the TZM/WRe interface after enduring 100-cycles thermal shock. The bending strength and shearing strength of the TZM/WRe joint are 910 MPa±65 MPa, 497 MPa±50 MPa, respectively. Fracture occurs in the TZM alloy, and the fracture mode is dominated by transgranular cleavage fracture.