Analyzing the dimensional errors in wire electric discharge machining of squeeze casted Al2024/Al2O3/W composite using cryogenic treated electrodes

Abstract

Distinctive attributes of hybrid aluminum matrix composites enhance their industrial applications; however, reinforcement particulates complicate their machining, specifically when intricate profiles with high precision are involved due to their intended applications. This study investigates the dimensional accuracy of squeeze casted Al2024/Al2O3/W hybrid composite during wire electric discharge machining. A cone-shaped convoluted profile has been opted for machining to address the industrial needs, therefore, dimensional deviation in length, vertex angle and curvature radius of specimens have been assessed. The influence of cryogenic treatment of wire electrodes has been analyzed to control dimensional deviation in machining. Besides this, the influence of four machining variables including pulse duration, wire feed rate, wire runoff speed and wire tension on the dimensions deviations has also been investigated. The findings indicate that the pulse duration and wire tension notably influence the length error and curvature radius error. Additionally, the pulse duration and wire feed rate have been found to significantly impact the vertex angle error. The non-treated wire creates more significant craters and macro voids on the machined surface due to uneven sparking. In contrast, due to its enhanced electrical properties, the cryogenic-treated wire exhibits a comparatively refined microstructure on the machined surface, displaying fewer micro-voids and shallow craters. Comparative analysis shows that cryogenically treated wire offers 65.5 %, 35.3 % and 33.4 % reduction in length error, vertex angle error and curvature radius error than non-treated wire. The findings of this study can be helpful for the manufacturing industry for precision machining of intricate geometries.