Numerical and experimental studies on dissimilar joining of Hastelloy C-276 and SS-316L using microwave hybrid heating at 2.45 GHz

Dissimilar joints of SS-316L and C-276 (Hastelloy) were developed using C-276 powder with microwave exposure 600 s in microwave applicator (2.45 GHz, 900 W). A multi-physics model was validated with experimental studies and simulation were carried out to analyse the microwave-joint interaction characteristics. The simulation results showed that a concentrated electric field (5.86 × 10 4 V/m) and higher resistive losses (3.07 × 10 7 W/m 3 ) at the joint region facilitated rapid heat generation locally. Microstructural characterization of the joint revealed the formation of cellular grains such as Fe-Ni intermetallic phases with Mo, Cr and W-carbides along the grain boundaries. Joints exhibited average microhardness of 290 HV, and tensile strength of 425 ± 10 MPa and 14% elongation with failure due to both ductile and brittle fracture modes.