Evaluation of mechanical and metallurgical properties of SS 304-CP copper dissimilar metal joint by innovative pulsed-GTAW process

The dissimilar joining of stainless steel (AISI 304SS) and commercially pure copper was carried out with an innovative pulsed gas tungsten arc welding (P-GTAW) process without using any type of filler material. The use of no filler metal technique leads to a greener and sustainable manufacturing practice. A Taguchi orthogonal array-based design matrix (L16:34) was developed for the whole experimentation. An acceptable top surface integrity was measured as 120-230 µm by the surface profilometer. The utmost tensile stress of the weld was achieved as 276 MPa. The ductile fracture refers to numerous dimples found on the fracture surface and concludes that failure occurs at the copper side. The microhardness in the fusion zone was observed 140~200 HV and the lowest value was recorded at the heat affected zone (HAZ) of copper compared to other zones. The microstructure analysis shows the proper mixing of Fe and Cu in the fusion zone.