An investigation on the parameter optimization and abrasive wear behaviour of nanostructured WC-10Co-4Cr TIG weld cladding

Abstract

In the present research work, a highly wear resistant nanostructured WC-10Co-4Cr cladding has been deposited on AISI-304 stainless steel substrate by using TIG welding process. The WC-10Co-4Cr feedstock powder and claddings developed at different processing conditions were characterized by using FE-SEM, EDS, and XRD analysis. Microhardness and fracture toughness values of the deposited claddings have been evaluated by using Vickers hardness tester. Abrasive wear testing has been conducted by utilizing pin-on-disc tribometer against the SiC abrasive counter surface. TIG cladding process parameters were optimized by employing the central composite design based upon response surface methodology. The results revealed that the welding current has the maximum influence on the hardness and wear resistance of claddings followed by welding speed and standoff distance, whereas, argon gas flow rate has the minimum impact. The developed mathematical models for hardness and wear have been validated. The error between the experimental and predicted values lies within the acceptable range. Microstructural examination revealed that material removal has occured due to the pull-out of WC grains and eruption of soft CoCr matrix caused by the SiC abrasive particles during the sliding motion.