Hard PVD coatings nc-(Ti_(1-x)Al_x)N/a-Si_3N_4 not only for dry machining

摘要

Nanocomposite coatings nc-(Ti_(1-x)Al_x)N/a-Si_3N_4 prepared by PVD technology based on low voltage arc and using two cylindrical central cathodes, which were made from Ti and AlSi, respectively, were studied for various combinations of evaporating cathode current on the both cathodes. All the depositions were done on the coating unit of a production size and the results were used in the industrial production. XRD, SEM-EDS, TEM resp. HRTEM methodes were used for structural analyses. GD OES method was used for composition analysis. The hardness measurements; were done by means of the load-depth sensing technique using Vickers diamond indentor at a maximum load of 70 mN. The effect of the substrata bias on the stochiometry, crystallite size and mechanical properties of the deoosited films was investigated. The crystallite size increases from 3 rm to more than 100 nm when the bias voltage decreases from - 200 to - 50 V and the titanium content increases from 35 to 90 at. %. The surface roughness decreases with increasing bias. The plastic Vickers hardness was n the range between 30 GPa to 47 GPa. The mechanical properties were also studied after the annealing at 800℃.