Wettability and thermal contact resistance of thermal interface material composite d by gallium-base d liquid metal on copper foam

As a promising thermal interface material (TIM), gallium-based liquid metal (GBLM) could significantly reduce the thermal contact resistance (TCR) at the solid-solid interfaces, while the leakage of GBLM and the wettability between liquid metal and solid surface restrict further application. In this study, the GBLM was wrapped with a copper foam (CF) skeleton, which prevents leakage and improves the thermal con-ductivity of the GBLM. Gallium-based liquid metal-copper foam (GBLM-CF) TIM was prepared by the self -wetting of the CF surface through the galvanic corrosion of GBLM. As the concentration of HCl increases from 0 to 5 M, the interfacial tension (IFT) in the HCl solution decreases from 536.80 +/- 1.00 mN/m to 4 81.52 +/- 0.4 9 mN/m, demonstrating that the IFT of the GBLM is inversely proportional to the concentra-tion of HCl. Meanwhile, the decrease of contact angle (CA) by 8 degrees indicates that the presence of CuGa2 on the surface promotes the wettability of GBLM. With the increase of external pressure and the improve-ment of wettability, the TCR between the GBLM and the copper sheet decreased by 58.28%. The TCR of the sample using GBLM-CF as TIM is 83% lower than that of thermal grease. Moreover, the thermal conduc-tivity of GBLM-CF TIM (51.58 +/- 0.01 W/(m center dot K)) is 212.6% higher than that of GBLM (16.50 +/- 0.02 W/(mK)). The GBLM-CF TIM presented in this study can be used for the efficient thermal management of electronic equipment. (c) 2022 Elsevier Ltd. All rights reserved.