Experimental investigation and predictive model for Al–SiC metal matrix composite heat sink thermal contact conductance

Metal Matrix Composites (MMCs), like aluminum with silicon carbide reinforcement, allow customization of thermal properties thereby improving thermal cycling performance in electronic equipment heat sinks. This study addresses the estimation of thermal contact conductance (TCC) of Al–SiC MMCs used in heat sinks by considering variations in SiC percentage and surface roughness under different applied pressures. Response Surface Methodology is used for the design of experiments, and measurement of actual contact area is performed to analyze the changes based on the considered parameters. For an exceptionally smooth surface ( R q = 0 . 2 μ m), the real contact area constitutes only 38.09% of the nominal area at 2 M P a , increasing significantly to 80.54% at 16 M P a . This highlights that TCC is more sensitive to variations in applied pressure than to surface roughness, with TCC showing a 463.17% increase for a fixed roughness ( R q = 2 . 5 μ m, 12.09% SiC) as pressure rises from 2 MPa to 16 MPa, while only a 23.84% decrease is observed when surface roughness increases from R q = 0 . 2 μ m to R q = 5 μ m at constant pressure (9 MPa). Furthermore, prediction models for TCC are also presented, utilizing regression analysis. The chosen model accurately predicts TCC within ±10.45% error margin, highlighting its reliability in estimating TCC in MMCs. • Experimental investigation to estimate TCC of Al–SiC MMC under uni-axial loading. • Proposed predictive model for TCC using SiC %, roughness, and contact pressure. • Analyzed SiC interfacial/bulk effects on TCC via contact area, thermal conductivity. • Skewness and kurtosis reveal deviation from Gaussian surface assumption in MMCs.