Initial driving force for PVD thin film coating development
The initial driving force for PVD thin film coating development was the desire to increase the wear performance of tools, especially in the automotive industry. Surface modification was required to enable high-speed machining of light, durable aluminium and titanium alloys with minimal lubricant. Therefore most research and development was focussed on hard (>1,000 HV) thin film coatings.
Hard materials for thin film coatings
Hard materials suitable for thin film coatings are predominantly but not entirely carbides, nitrides, borides and silicides of the IVth, Vth and VIth groups of the periodic table. Such materials are formed by introducing nitrogen, hydrocarbon, or silicide during the sputtering process. It is thought that the compound is formed at the surface of the substrate. An example being titanium aluminium carbo-nitride, TiAlCN.
TiAlCN, (a=lattice parameter)
Attention recently has focussed on the development of hard, wear resistant, low friction thin film coatings such as Graphit-iC™ and MoST™, with the automotive industry again the driving force. If you want to know more about low friction thin film coatings or PVD clicks the links or contact me.