Experimental investigation and empirical modeling of EDM performance and mechanical properties of in-situ synthesized A356-TiB ₂ composite using Box–Behnken based RSM

This research work experimentally studied the mechanical characteristics and Electrical Discharge machining (EDM) machinability of in-situ synthesized A356-TiB2 composites using Box–Behnken based RSM. The composite exhibited an average tensile strength (TS) of 251 MPa (248–254 MPa), impact strength of 6.93 J (6.8–7.1 J), and microhardness of 120 HV (118–122 HV), confirming enhanced strength and hardness due to uniform distribution of TiB2 particles. EDM of A356-TiB2 composite was conducted by varying discharge current (Dc):4–12 A, pulse-on time (Pon): 40–80 µs, and pulse-off time (Poff):10–30 µs, The maximum material removal rate (MRR) of 60.18 mg/min was attained at 12 A, 60 µs, and 10 µs, while surface roughness (Ra) ranged from 3.73 µm to 6.93 µm, with the lowest Ra at 4 A and 40 µs. The developed quadratic models demonstrated high statistical significance with R2 values of 99.46% for MRR and 99.55% for Ra. ANOVA identified Dc as the most dominant factor, contributing F-values of 711.39 for MRR and 823.76 for Ra (p < 0.001). SEM examination revealed enlarged crater, microcracks, resolidified globules, and TiB2 at higher discharge settings. The study established empirical relationship for predicting EDM performance and identified optimal parametric level.