<p>Taguchi S/N technique is employed to optimize the drilling parameters in order to minimize the thrust force (TF), surface roughness (Ra), and burr height (BH) of LM5 alloy-based hybrid composite. AMCs was manufactured using the stir casting method, adding 6% ZrO₂ and 2%, 3%, and 4% graphite (Gr) particles as reinforcement with LM5 as matrix. TF, Ra, and BH were taken into consideration as the output response, whilst the other process parameters Spindle Speed (SS), Feed rate (FR), Drill Materials (DM) and Reinforcement Percentage (R%), were selected as the input characteristics. Drilling was done based on the Taguchi L₂₇ orthogonal design according to the parameters that were chosen. The best variable setting and its effect on Tf, Ra, and Bh for the drilled composite were determined by applying the S/N (signal-to-noise) ratio and ANOVA (analysis of variance). The S/N ratio findings showed that the first level of FR (A₁), level three of SS (B₃), level three of DM(C₃), and level one of R% (D₁) all reached the lowest value of T_f. The largest contributor to TF (51.32%) is FR, followed by SS (37.37%) and DM (3.96%). Thrust force increased significantly with increasing feed rate due to higher undeformed chip thickness and greater resistance offered by the hard ZrO₂ particulates, whereas higher spindle speed reduced Tf by thermal softening of the matrix and smoother chip shearing. First level of FR (A₁), the third level of SS (B₃), level three of DM (C₃), and level two of R% (D₂), the lowest value of Ra was attained. The largest contribution to SR is made by DM (44.83%), followed by SS (30.51%) and the FR-SS Interaction (15.93%). The superior performance of the coated carbide drill was attributed to its higher hardness, lower friction coefficient, and better wear resistance, which suppressed edge chipping and built-up edge formation. Higher spindle speed enhanced surface finish through stable cutting action, while excessive feed worsened Ra due to feed marks and particle pull-out. The best process variables for reaching the minimal BH are input variables at level A₃ (150&#xa0;mm/min feed), B₃ (3000&#xa0;rpm speed), C₃ (Coated Carbide drill bit), and D₂ with 6% reinforcement. BH is most exaggerated by SS, which is followed by DM, R%, and FR. Elevated spindle speed promoted cleaner fracture of the exit edge and reduced plastic deformation, while the coated carbide drill generated lower burrs because of sharper cutting edges and reduced adhesion. Moderate reinforcement content improved edge rigidity; however, excessive graphite reduced matrix support and promoted burr formation. A regression model showcases the impact of drilling parameters on TF, Ra, and BH has been developed. The study establishes scientifically optimized drilling conditions for LM5/ZrO₂/Gr hybrid composites and provides practical guidelines for producing high-quality holes with reduced machining damage in lightweight structural applications.</p>