Nickel Superalloy Components Surface Integrity Control through Numerical Optimization

Abstract

Different parameters are used to evaluate the machined surface quality; roughness, residual stress and white layer are the most common factors that affect the surface integrity. Residual stress, in addition, are one of the main factors that influence the component fatigue life. Superficial residual stresses depend on different factors, such as cutting parameters and tool geometry. This article describes the development of an automated optimization procedure that allows the matching of a residual stress Target Profile by varying process parameters and tool geometry for a typical aeronautic superalloy, such as Waspaloy, for which a reliable numerical model has been developed for comparison to experimental data. The objective of this procedure is to maximize the Material Removal Rate under physical constraints represented by appropriate limits assigned to: Cutting Force, Thrust Force, Tool Rake Temperature and residual stress Target Profile. The developed optimization procedure has shown its effectiveness to match a given residual stress profile in accordance to process responses numerically evaluated.