Optimization and prediction of hardness, wear and surface roughness on age hardened stellite 6 alloys

Abstract

Growing demand for Stellite 6 alloys due to its attractive properties such as superior strength, toughness, wear resistance, fracture resistant characteristics, and their exceptional resistance to corrosion has made them applicable in industrial as well as commercial applications, such as aerospace industries, nuclear waste storage, automobile industries and surgical implantation. However, in spite of these applications, automotive part manufacturers mainly (Bearing Materials) are looking for a comprehensive study, such as mechanics of friction and the relationship between friction and wear. Hence in this paper, an attempt has been made to study the tribological behavior such as wear characterization and surface roughness of age hardened Stellite 6 alloys. The main objective of the research is to determine the favorable tribological conditions for improving wear resistant properties and surface roughness on age hardened Stellite 6 alloys. Hence two body wear study and surface roughness study during Wire Electric Discharge Machining (WEDM) of age hardened Stellite 6 alloys based on Analysis of Variance (ANOVA), Taguchi's Design of Experiment (TDOE), Response Surface Methodology(RSM) and Desirability Functional Analysis (DFA) have been used to achieve this goal. From the study it is observed that optimum values for improving hardness, wear and surface roughness values can be easily achieved with less time and cost by adopting the said techniques. •From microstructural observation, as the peak current increases there is larger amount of dendritic carbides and cracking of carbides due to high plastic deformation resulting in thermal softening of Stellite 6 alloy during wire electric discharge machining resulting in better surface roughness values. The second-order model for hardness, wear and surface roughness using response surface methodology can be adopted for predicting for hardness, wear and surface roughness in any experimental domain.