DEVELOPMENT OF COPPER COATING ON AUSTENITIC STAINLESS STEEL THROUGH MICROWAVE HYBRID HEATING

In the present work, copper coatings have been developed by a novel route, where microwave radiation of 2.45GHz has been used as the heating source. The developed coatings were analyzed through field emission scanning electron microscope (FE-SEM), x-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), Vicker's microhardness analysis and four-probe method for electrical resistivity measurement. The copper coatings with average thickness of similar to 230 microns were successfully deposited through exposure of microwave radiation using 900W power on austenitic stainless steel substrates by hybrid heating process. The copper powder particles were partially fused during interaction with microwave radiations. The deposited coatings exhibit dense and homogeneous microstructure. The microstructure of transverse section shows 3-D chain like network of partially fused copper particles. The developed coating gets oxidized during processing as revealed in XRD spectrum. It was found that the coatings so developed had a mean hardness of 272 +/- 30 (Hv). The copper coatings show sudden transition in electrical resistivity at similar to 18 degrees C.