A Study Of Microstructures And Mechanical Properties Of Cathodic Arc Deposited CrCN/ZrCN Multilayer Coatings

• Main Authors: Tung, Cheng-Yi, 童正億
• Other Authors: Kuo, Chil-Chyuan
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/00319428033694817647

碩士 === 明志科技大學 === 機電工程研究所 === 100 === Chromium nitride coating is characterized for its adequate mechanical properties, corrosion and oxidation resistance. Zirconium nitride coating shows the advantage of high hardness. The addition of carbon into the chromium nitride and zirconium nitride coatings can improve the hardness and tribological properties effectively. In this study, a series of higher nitrogen contained chromium carbonitride (CrCN), zirconium carbonitride (ZrCN) and nanomultilayered CrCN/ZrCN thin films with different carbon contents were grown by the cathodic arc evaporation (CAE) deposition method using different flow ratios of N2 and C2H2 gas mixture. The crystalline structure, surface roughness, microstructures, hardness, adhesion and tribological properties were evaluated. It was observed that the surface roughness and grain size decreased with increasing C content. For the CrCN and ZrCN coatings, a nanolaminated structure was obtained when the C2H2 gas flow rate was higher than 17.5 sccm. The lattice constant of CrCN and ZrCN film increased due to the interstitial effect of carbon atoms into the lattice when the carbon content was low. On the other hand, the replacement of nitrogen by C atoms was found to reduce the lattice constant when the C content was high. The maximum hardness was obtained for CrCN coating containing 3.3 at.%, C content. Better adhesion and tribological properties were achieved when the C content was higher than 4.7 at.%. For the ZrCN coating containing 5.9 at.% C, the highest hardness、better adhesion and tribological properties were performed due to the solution hardening effect of C atoms. The hardness was maintained around 27~28 GPa for CrCN/ZrCN multilayered thin film with different carbon contents. The adhesion property increased with increasing carbon content of nanolaminated thin film. The better tribological performance was found when the carbon content was 4.1 at. %.