The Entropy Method Integrated RSM Model to Evaluate Hole Geometries in Electrochemical Blind Hole Drilling

Abstract

The electrochemical drilling (ECD) process enables the machining of conductive materials with a wide range of hardness, yield strength, and brittleness. In this study, the ECD experiments have been conducted on blind hole drilling in high-speed steel material using a tailor-made ECD machine. The hole geometries (cross-sectional profiles) at different machining parameters have been examined for the hole depth consistency (HDC), hole cross-sectional area (HCAC) and the hole profile length (HPLC) evaluation (response; output) metrics introduced. The relationships between the hole geometry evaluation metrics and machining parameters are obtained using the response surface method (RSM). Using the Entropy method, an optimisation model is also proposed to combine multiple responses into a single objective function. The effectiveness of the Entropy method is compared with the Analytical Hierarchical Process (AHP). The comparison showed that the Entropy model provides more robust and convenient results than the AHP approach. © 2025 Elsevier B.V., All rights reserved.