RECENT DEVELOPMENTS IN HARD COATINGS

Films consisting of CNx, TixAlyN, and crystalline-TiN/amorphous-Si3N4 were grown using IBAD with Ar or N. The substrate material was polishe d (100) Si. The Films were analysed using RES, HRTEM, SNMS, and nanoin dentation techniques. In the first study a nitrogen content as high as 55% in CNx films was achieved by using a novel encapsulation techniqu e. In a second study it has been shown that the hardness of TixAlyN in creases from 1600 kgfmm(-2) to 3460 kgfmm(-2) when using IBAD. Further more, thr maximum hardness is achieved by a composition approaching Ti 0.5Al0.5N. Finally, a preliminary study involving the growth of nanocr ystals of TiN imbedded within an amorphous Si3N4 matrix shows that the hardness approaches a maximum value of 2450 kgfmm(-2) when the silico n content is about 8%. However, the hardness is not as great as previo usly reported films grown by plasma enhanced CVD. The grain size of th e TiN is approximately 10 nm which is greater than the predicted optim um values of 3-5 nm.