Study of joining copper-mild steel using microwave energy

Abstract In the present work, joining of dissimilar metals using electromagnetic energy has been successfully achieved. A 900 W multimode microwave applicator at the fixed frequency of 2450 MHz was used to generate the required heat energy for joining. Copper (Cu) and mild steel (MS) were chosen as the base material to be joined. Copper metal powder in the form of the thick slurry was prepared and used as a joining agent between two bulk interfaces. The joining process was carried out through the controlled emission of microwaves at a particular area for a particular period of time. Due to these controlled emissions of microwaves, the slurry of metal powder got melted and produced a fine bond with the bulk interfaces on cooling. To understand the nature of the joint formation, joints were characterized by using an optical microscope, SEM, X-ray diffractometer, microhardness tester, and Universal testing machine. Analysis of SEM resulted in a well-defined, merged, and fused joint. The microhardness at the joint zone was recorded to be 73 ± 4 HV and 78 ± 6 HV on copper side and MS side respectively. Strength test results showed the UTS of 170 MPa with 13.25% elongation.