Abstract
Monitoring the wear life of the tribological amorphous carbon (a-C) film through luminescent spectroscopy is proposed. The monitoring can be achieved by detecting the degree of luminescence from the layer that is located under a-C film. Hence, the structure of the coating consists of substrate/luminescent sensing layer/a-C layer. In this study, fabrication and characterisation of such coating structure are presented. Firstly, the coating structure, in which the luminescent sensing layer is ZnS:Mn thin films, was fabricated. The thin films were deposited by R.F. magnetron sputtering in argon plasma and post-annealing at 700°C. Subsequently, a-C films were deposited onto the luminescent layer by R.F. magnetron sputtering. The structures of the coatings as well as luminescent properties were analysed. However, due to the requirement of high temperature annealing to enhance the luminescent properties of ZnS:Mn thin film, silica coatings containing CdSe/ZnS quantum dot powder prepared from polysilazane precursor solution were also fabricated for another candidate for luminescent layer. The process is found to be simpler and requires significantly lower temperature annealing process.
