October 2017: Prof. Paul Munroe, "The microstructure and mechanical properties of thin film Ni(Ti)"
Thin film coatings applied to, for example, tool steel substrates are commonly used to protect the steel during high wear machining operations. In this study, a series of coatings were prepared where small amount of titanium, oxygen and nitrogen were added to nickel-rich coatings prepared by magnetron sputtering. As the nitrogen content of the coatings increased, the volume fraction of titanium nitride, a phase well known for its high hardness, increased but conversely the hardness of the coatings decreased (but coating toughness increased). This was attributed to a smaller concentration of titanium dissolved in solution in the nickel, which reduced the extent of any solid solution strengthening effects.
Fuyang Cao, Paul Munroe, Zhifeng Zhou and Zonghan Xie
Read the full article, as published in Surface and Coatings Technology, Vol. 304, 25 Oct 2016, pp 375-383.