Characterisation of sputter deposited niobium and boron interlayer in the copper-diamond system

► The interface in the Cu-C system was modified by boron and niobium interlayers. ► Thermal treatment of the samples simulated the production process of Cu-diamond MMCs. ► The TCR of the interface was investigated by modulated infrared radiometry. ► Chemical- and diffusion processes were investigated by TEM of interlayer cross sections. ► Very thin interlayers improve the mechanical and thermal interfaces.