The wettability and interface thermal resistance of copper/graphite system with an addition of chromium

In the present work, the wettability and interface thermal resistance (ITR) of copper/graphite (Cu/Gr) system with an addition of chromium (Cr) was studied. First, alloy element of Cr (1.0 wt.%) was introduced in copper to improve the wettability of Cu/Gr system. The wetting procedure of liquid Cu–Cr alloy on graphite substrate was studied by sessile drop method. It was found that the contact angle decreased to 43° with addition of Cr. Then, an experimental method was employed to determine the ITR of Cu/Gr system. Results reveal that the ITR decreased significantly with the introducing of Cr. It suggested that the reduction of ITR related to the formation of a continuous carbide layer at the interface zone which consisted of Cr7C3 and Cr3C2.

► This work offers a comprehensive evaluation on the influence of Cr in Cu/Gr system. ► The final contact angle decreases to 43° with the introducing of Cr at 1573 K. ► The ITR of Cu–Cr/Gr system decreases obviously at 1573 K for 60 min. ► ITR is sensitive to the continuity and thickness of carbide layer at the interface.