IBAD processing of surface coatings and nanocrystalline multi-layers

Multi-functional ion beam assisted deposition (IBAD) equipment with 8 targets and 4 ion sources has been developed to synthesize coatings and multi-layers of many combinations. DLC, TiN, TiC coatings have been investigated with special attention paid to DLC. It is found that a narrow energy window exists at about 200 eV in order to serve more prominent diamond bondings and diamond-like properties. The surface is hard and smooth with a friction coefficient of less than 0.05. The improvement of the interfacial structure enables DLC coatings on 52100 steel to sustain uniform wear at high wear loads (up to 120 N). Applications of DLC and other coatings in material surface modification are being explored. By alternate sputtering, TiC/Metal multi-layers have been prepared. The individual Layers vary in thickness from 1 to 10 nm and the periods vary from 3 to 18 nm. The ceramic phase has been maintained as TiC, whilst Fe, Cr, Nb, Zr, Ni, Cu and Al have been used as the metal phase. The hardness and toughness of these laminated nanocrystalline films have teen investigated, the results showing the dependence of the properties on the modulation of the multi-layers as well as on the characteristics of the metal phase.