In-situ fabrication of TiC-Al2O3 and TiB2-TiC-Al2O3 composite coatings on 304 stainless steel surface using GTAW process

Abstract

The purpose of this study was to improve the performance of 304 stainless steel by applying a wear-resistant coating. For this purpose, in-situ composite coatings of TiC-Al2O3, as well as TiB2-TiC-Al2O3, were applied on the surface of 304 stainless steel by using combining, welding and self-combustion synthesis with different current welding. The microstructural investigations of the coated layers showed that due to the high incoming welding temperature in all the samples, by performing the combustion synthesis reaction, significant reinforcing particles were formed on the 304 stainless steel surface. Also, in all heat inputs, cubic titanium carbide particles formed inhomogeneously on Al2O3 particles or spontaneously in the austenitic matrix of 304 stainless steel. The reinforcing of TiC and TiB2 particles formation in both 3TiO2-4Al-3C and 3TiO2-4Al-B4C layers led to an increase in surface hardness and wear resistance up to 2.5 versus the substrate.