Influence of chemical bonding on thermal contact resistance at silica interface: A molecular dynamics simulation.

The chemical bonding is usually not avoidable at a welding or fusion interface and sometimes is desirable to enhance the mechanical strength, while it might strongly affect the thermal contact resistance which plays a critical role in hindering heat dissipation of electronic devices. In this paper, we employ a non-equilibrium molecular dynamics method to study the effect of chemical bonding on the thermal contact resistance. Results show that the chemical bonding can greatly affect the thermal contact resistance. With the increase of the chemical bonding ratios, the thermal contact resistance firstly drops dramatically until arrives at a bonding ratio of about 20% where the thermal contact resistance is only about 15% that with a bonding ratio of 0%, and then gradually decreases to 0. Analyzing the spectral energy density of phonons at the interface, we conclude that the increase of the phonon velocity should be responsible for the decrease of the thermal contact resistance. By simulating the thermal contact resistance of silica with different morphologies (crystalline or amorphous silica), we found that different morphologies could lead to different thermal contact resistances, although this difference is less than 6%. This study is expected to provide references for managing thermal transport at a welding or fusion interface. [ABSTRACT FROM AUTHOR]