The tribological characteristics and turning, drillingperformance of Cr-N and Cr-O coatings deposited by unbalanced magnetron sputtering

• Main Authors: Chung-Whei Lin, 林琮暉
• Other Authors: Y. L. Su
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/60642889934819904447

碩士 === 國立成功大學 === 機械工程學系碩博士班 === 94 === In this study, Cr-N and Cr-O coatings were deposited on the SKH51 disks, silicon wafers, micro-drills and indexable inserts by closed field unbalanced magnetron system. The main purpose of this study is to research mechanical, tribological properties and cutting performance of the Cr-N and Cr-O coatings. The experiment is divided into two stages. In the first stage, the effects of gas flow rate and substrate bias voltage on the mechanical properties of Cr-N and Cr-O coatings were investigated. In the second stage, the effect of high temperature oxidation treatment on the mechanical properties of Cr2N coatings was investigated. Finally, the actual cutting performances of the optimal coatings from the first two stages were understood in the turning and micro-drilling tests. The results reveal that the highest hardness HK10g 2176 and the best wear resistance were performed by Cr2N coatings at the nitrogen gas flow rate 10 sccm and substrate bias voltage -40 V. The hardness of Cr-O coatings was increased by increasing oxygen contents. High hardness value HK10g 2036 was performed by Cr-O coatings when oxygen contentis 20 at. %. The best wear performance was achieved by Cr-O coatings when oxygen content is 5 to 15 at. %. The lowest friction coefficient was performed by Cr-O coatings when oxygen content is 3 at. %. After high temperature oxidation treatment, the hardness and wear resistance of Cr2N coatings were apparently increasing. Wear from cutting tools can be reduced by high temperature oxidation treatment Cr2N thin films coated on inserts and drills during actually turning and micro-drilling tests. About three times insert wear and ten times drill wear can be reduction.