Interface characterisation and wettability properties of carbon particle reinforced copper alloy

The effect of carbide alloying elements such as chromium and tin upon the b onding state and the interfacial carbon/copper zone in a copper melt have b een investigated. The reactivity behaviour, contact angle and the kinetics of wettability have been investigated for each system studied (C/Cu, C/Cu-S n, C/Cu-Cr and C/Cu-Sn-Cr) using Auger electron spectroscopy and line profi le/sessile drop experiments performed under ultra high vacuum conditions. N on-wetting systems such as C/Cu and C/Cu-Sn are characterised by (i) an adh esive solid-solid bond strength and van der Waals interactions and (ii) mon otonous behaviour during experiments where the kinetics are controlled by t he viscous flow of the liquid drop over the solid substrate. Wetting system s such as C/Cu-Cr and C/Cu-Sn-Cr show a completely different behaviour. For these two systems, chromium tends to segregate at the reinforcement/metal interface, forming a stable carbide compound. Chromium segregation and carb ide formation processes lead to different kinetics of wettability which can be summarised in a three step process.