Development of VN(vanadium nitride)-containing coating film having high-temperature lubricity and its application to machining difficult-to-machine materials

2020 Fiscal Year Final Research Report

• Project/Area Number: 18H01349
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 18020:Manufacturing and production engineering-related
• Research Institution: Kanazawa University
• Principal Investigator: Hosokawa Akira 金沢大学, 設計製造技術研究所, 教授 (40199493)
• Co-Investigator(Kenkyū-buntansha): 小谷野 智広 金沢大学, 機械工学系, 准教授 (20707591) ; 古本 達明 金沢大学, 設計製造技術研究所, 教授 (60432134) ; 橋本 洋平 金沢大学, 機械工学系, 助教 (30456686)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: PVDコーティング / 窒化バナジウム / 多層膜 / マグネリ相 / 潤滑性 / 切削工具 / エンドミル / 工具摩耗

Outline of Final Research Achievements

The multilayer coatings with lubricious VN and heat resistant AlCrN are developed. According to the nanoindentation hardness, critical scratch load, and friction coefficient, the multilayer VN/AlCrN-coated films have mechanical and tribological properties to comparable to those of the TiN, AlCrN, and VN films. Owing to the formation of Magneli-phase oxides, the friction coefficient decreased as the temperature increased above approximately 500deg.
The cutting forces of the VN-rich VN/AlCrN-coated tools were lower than those of TiN and AlCrN-rich tools, which were mainly caused by the tribological effect of the lubricious VN film. Meanwhile, the flank wear width of the multilayer VN/AlCrN-coated tools were relatively small due to the higher harness of the VN film. In addition, the cutting temperature of the VN/AlCrN-coated tools were considerably lower than that of the VN-coated tool, indicating a synergetic effect for wear resistant AlCrN and self-lubricating VN coating materials.

Free Research Field

工学 機械工学 生産工学・加工学

Academic Significance and Societal Importance of the Research Achievements

本研究ではAIP法によってVN/AlCrN-多層膜を創成した．VNコーティング膜は500℃以上の高温において表面に摩擦係数の低い酸化バナジウム層を形成する．他方，AlCrNコーティング膜は高温下において表面に耐熱性の高い酸化アルミニウム層が形成される．したがって，VN膜とAlCrN膜を多層化することで耐熱性と潤滑性を兼ね備えたコーティング膜となり，難削材(Ti合金，Ni基耐熱合金など)の切削加工の高速・高能率化が実現できる．
また，本研究は膜種自体の特性と膜種に起因した反応生成物の複合作用で潤滑性，耐熱性，母材との密着性等に優れたコーティング膜を創成したものであり，学問的にも意義がある．