Development and Characterization of HVOF Sprayed Coatings in Improving Resistance to Erosion and Wear

Abstract

Structural components fail in high-temperature situations because of the atmosphere contact with newlinethe material, resulting in erosion, wear as well as successive enhanced degradation. The present newlineresearch work explores the possibility of using HVOF coatings on the materials used in high newlinetemperature applications such as boilers, turbines and automobile parts. The coatings are newlineinvestigated for their resistance to erosion and wear, under laboratory conditions. newlineThe six feedstock powders CrC-NiCrFeSiBCoC (35%-65%), CrC-NiCrFeSiBCoC (80%-20%), newlineWC.Co-NiCrAlYSi (35%-65%), WC.Co-NiCrAlYSi (80%-20%), WC-NiMoCrFeCo (35%-65%) newlineand WC-NiMoCrFeCo (80%-20%) used in the study are coated on the substrate material namely newlineFe-based Super alloy designated as SS316 (Midhani Grade). The microstructure and several newlineproperties have been characterized to evaluate their potential as high temperature erosion and wear newlineresistant coatings for high temperature applications. newlineThe solid particle erosion experiments were carried out using air jet erosion test rig at 30°, 60° and newline90° impact angles under alumina sand as an erodent. The wear test experiments were carried out newlineusing pin on disc sliding wear equipment at varying loads of 30 N, 40 N and 50 N, constant speed newlineof 600 rpm and at varying speeds of 500 rpm, 600 rpm and 700 rpm, constant load of 50 N to newlinedetermine the coefficient of friction and specific wear rate. The samples subjected to erosion and newlinewear were analyzed using optical microscopy, Scanning electron microscopy/Energy dispersive newlineX-ray analysis (SEM/EDAX). newlineThe HVOF sprayed CrC-NiCrFeSiBCoC (35%-65%) and CrC-NiCrFeSiBCoC (80%-20%) newlinecoatings shows superior performance among the coatings used in the present study. It performs newlinewell under erosion and wear testing conditions. The WC/Co-NiCrAlYSi (35%-65%), WC/Co- newlineNiCrAlYSi (80%-20%) coating exhibits good resistance to erosion and wear. The WCNiMoCrFeCo newline(35%-65%) and WC-NiMoCrFeCo (80%-20%) coatings have less resistance to newlineerosion and wear. newlineKeywords: Erosion, Wear, Coatings, HVOF, Coating thickne