Diamond-like carbon/Cu composite films on stainless steel: synthesis and investigation of heat transfer properties

This study details the creation of composite films consisting of amorphous hydrogenated diamond-like carbon (DLC) and copper on stainless steel, exploring their impact on heat transfer properties. Analysis of growth morphologies indicates the development of diamond crystals in a nanocrystalline ballas-like form on stainless steel substrates, suggesting radial growth of the crystals. Raman spectroscopy of the films reveals the presence of the T2g vibration mode of diamond crystals alongside D and G bands. The downward shift of the T2g peak to 1157 cm−1 suggests the formation of nanocrystalline diamond. Additionally, Cu–O vibration peaks are detected, attributed to atmospheric copper oxidation at the surface. Raman mapping, based on intensities corresponding to Cu–O at 450 cm−1 and the E2g phonon mode of sp2 bonded carbon at 1580 cm−1, indicates a uniform distribution of copper and DLC films. The application of a diamond-like carbon/Cu composite film significantly enhances the heat flux on the surface of stainless steel. While the uncoated surface exhibits a heat flux of 100 W/m2, the presence of DLC/Cu composite coating elevates it to 450 W/m2.