Investigation of surface damage and roughness for nickel-based superalloy GH4169 under hard turning processing

Machined surface condition of nickel-based superalloys has an important influence on the functional performance of the components. Proper selection of cutting parameters could improve surface finish and increase service life of parts and components. This research work bases on an experimental and statistical study of turning GH4169 nickel-based superalloy with cemented carbide tool. Surface damages like feed marks, tips, and surface tearing were discussed. The second-order polynomial model was used to describe the surface roughness response. Variance analysis was selected to eliminate the insignificant variables in the roughness model. The response surface methodology was used to investigate the combined effect of cutting parameters on two different dimensions surface roughness parameters. The optimization of cutting parameters for minimum surface roughness was obtained using desirability function method. The results demonstrate that feed rate has the most significant effect on surface roughness. High cutting speed and low feed rate result in better surface quality, but too low feed rate exacerbates built-up edge phenomenon and deteriorates surface condition. Optimal cutting parameters leading to the minimum surface roughness were highlighted.