Optimization of wire-cut electric discharge machining process parameters for hybrid MMC(AA7475/ZrO2/gr) using Taguchi method: an experimental study

Abstract

Metal-matrix composites (MMCs) and hybrid metal-matrix composites (HMMCs) are novel materials that possess distinctive mechanical characteristics, making them well-suited for industrial applications. This research implements an experimental study of the mechanical properties of HMMCs, where weight percentages (2, 3, and 4 wt. %) of zirconium dioxide (ZrO2) and graphite powder (Gr) are used as reinforcements and the aluminum alloy 7475 (AA7475) is used as a matrix. In this investigation, the stir casting method was used to prepare the composite by using AA7475 alloy with pre-heated reinforced particles of ZrO2 and graphite with various reinforcement weight percentages. Among these combinations, AA with 4 wt. % ZrO2 and 2 wt.% Gr showed enhanced mechanical properties. The mechanical properties of the ultimate tensile strength, yield strength, and hardness were evaluated. A Scanning Electron Microscope analysis was conducted to study the reinforcement distribution in the matrix. The input parameters for wire-cut electrical discharge machining (WCEDM) are pulse-on time (TON), pulse peak current (IP), and flushing pressure (PF). The material removal rate and surface roughness are the output responses. Determining the ideal set of process parameters in WCEDM for HMMC also involved the use of the Taguchi design technique known as the L9 orthogonal array. The peak current for the MRR and flushing pressure for the SR are the most prominent parameters.

Keywords

• Hybrid metal matrix composites
• wire-cut electrical discharge machining
• aluminium alloy
• graphite powder
• zirconium dioxide
• stir casting