Investigation of Electrical Discharge Machining Properties of Reinforced Cryogenic Treated AA7075 Composites

Abstract

The demand for materials arises to improve the effi ciency of the structural, aerospace and automotive components. It induces to identifi cation and production of composite materials. Amongst the varieties, Aluminium Metal Matrix Composite is widely used in automotive and aerospace industries because if inheriting wide range of acceptable mechanical and tribological properties besides being constructive by holding high strength to weight ratio. Herein, ED machining properties of cryogenic treated AA7075-B4C composites were analysed. B4C particles reinforced Aluminium metal matrix composites were prepared by using one of the liquid metrological method viz. stir casting. The samples were cryogenically treated at various soaking time periods (12, 24 & 36 hours). In ED Machining, material removal (MR) rate, tool wear (TW) rate and surface roughness (Ra) parameters were analysed depending upon the inputs viz. soaking time (SoT), electrode gap (Gap), current, Pon (pulse ON time), Poff (pulse OFF time). Experimentation remarks that current be one of the mostly infl uencing parameter towards ED machining than any other considerations in this part of research.

A Hybrid Design of Experiment Approach in Analyzing the Electrical Discharge Machining Influence on Stir Cast Al7075/B4C Metal Matrix Composites

“…In the EDM process, random discharge between the electrode and the workpiece is connected by many tinny craters. The size of the craters formed on the machined surface is defined by the magnitude of discharge energy [5]. The small irregularity on a machined surface is termed surface roughness.…”

“…Due to high thermal energy, wider and deeper dimensions of the crater were developed on the work piece surface, and crater development increased the surface roughness. The size of the craters also depends upon the Ton; smaller craters are developed by short sparks with minimum heat, while larger craters are produced by the longer Ton due to the longer sparks with high heat [5]. The longer Ton results in higher MRR due to the high energy sparks discharged to each spark discharge.…”

“…For the scope, the optimization of a process involves identifying the ideal settings for controllable factors, aiming to maximize the desired process outcome. This pursuit of optimal settings enhances overall performance, leading to improved quality and efficiency [5].…”

“…Between other procedures, the Taguchi method stands as one of the most widely accepted and popular design of experiment (DoE) approaches [5]. Developed by Genichi Taguchi, this statistical methodology aims to enhance the quality and performance of products or processes.…”

“…Electrical discharge machining (EDM) is a non-traditional machining process used to shape metal parts by employing electrical discharges or sparks [4]. This method is highly effective for machining intricate shapes and hard materials that are otherwise challenging to process using conventional machining techniques [5]. During the EDM process, material removal occurs due to the electrical discharges between the tool and the workpiece.…”