Evaluation of cutting speed and surface roughness in WEDM of functionally graded A356-10 wt% Si3N4 composite
摘要
Functionally graded composites (FGCs) have planned spatial changes in the distribution of the reinforcement and thus radial gradients in hardness, thermal conductivity, and microstructure. In this research, Al (Aluminium) A356 alloy reinforced with Silicon Nitride (Si₃N4) FGC was fabricated through a vertical centrifugal casting technique. The optical microscope, X-ray Diffraction (XRD), and Vicker’s microhardness evaluator examined the gradient distribution of ceramic particles. Such gradients pose great problems in the Wire Electrical Discharge Machining (WEDM), where the distribution of spark energies and the capability to remove materials become a zone-dependent process. The main aim of the research work is to investigate the effect of various machining control variables on the Cutting Speed (CS) and surface roughness during the machining in WEDM. An L27 experimental design was employed to systematically evaluate the influence of pulse on duration, wire tension, wire drum speed, and different zones of the FGC. Analysis of Variance (ANOVA) revealed that pulse on duration had the dominant effect on CS (80.30%), while wire tension was the primary contributor to surface roughness (33.11%). The increase in CS is attributed to higher spark energy concentration and improved plasma stability, which enhance the rate of localized melting and material expulsion, whereas the uniform wire movement stabilized the spark discharge, thereby reducing surface roughness. These findings help optimize WEDM parameters for FGCs, improving engineering applications’ machining efficiency and surface quality.