Statistical modelling and ANOVA analysis of thermal contact resistance in solid-solid interfaces

Thermal contact resistance (TCR) limits interfacial heat transfer in solid-solid junctions and depends on several parameters, including surface condition and the thermophysical properties of the contacting materials. This study quantitatively evaluates the influence of material pairing (steel/steel, steel/copper, steel/nickel) and contact surface area (five levels: 0.05-0.8 mm²) on TCR and heat flux using a two-way analysis of variance (ANOVA) with interaction (n = 45). The results indicate that the contact surface area is the dominant factor affecting TCR (p < 0.001; 89.2% of the total variance), whereas the material type constitutes the primary factor governing heat flux (p < 0.001). A robust linear regression model (R² = 0.96) further confirms these trends. These findings provide a statistically sound framework for the optimization of thermal interfaces in power electronics applications, highlighting the superior performance of the steel/copper material pair.