Loic Constantin’s paper accepted in Carbon, December 2019 “Design of tailored oxide-carbide coating on carbon fibers for a robust copper/carbon interphase”
April 22, 2020
The lack of robust interphases between carbon and most metals prevent the exploration of the full scope potential of carbon-based metal matrix composites. Here, we demonstrated a scalable and straightforward way to produce strong interphase between copper (Cu) and carbon fibers (CFs) by designing a tailored titanium oxide-carbide coating (TiOy-TiCx) on CFs in a molten salt process. The oxide-carbide composition in the graded layer strongly depends on the coating temperature (800-950 ºC). A coating with a high TiOy content obtained at a low coating temperature (800 ºC) contributes to better molten-Cu wetting and strong adhesion energy between CFs and Cu during a subsequent exposure at 1200 ºC. The Cu wetting angle for the TiOy-TiCx-CF sample obtained at 800 ºC was ~80º ± 5º with a Cu surface coverage of ~50% versus ~115º and ~10% for the TiCx-CF sample made at 950 ºC. The kinetic analysis of the coating process step by step suggests a growth rate limited by the mass-transfer through the coated layer. This method provides a novel approach to improve the thermal conductivity of Cu/C composite for thermal management applications.