타이타늄 합금에 다양한 두께로 코팅된 TiN피막의 기계적 성질

Abstract

Titanium nitride(TiN) coatings are the most general and popular coating method and used to improve the properties of metallic surface for industrial purposes. When TiN coating applied to the abutment screw, frictional resistance would be reduced, as a results, the greater preload and prevention of the screw loosening could be expected. The purpose of this study was to investigate mechanical properties of TiN coated film of various coating thickness on the titanium alloy surface and to evaluate proper coating thickness. Titanium alloy(Ti-6Al-4V) discs of 15 mm in diameter and 3 mm in thickness were prepared for TiN coating and divided into 7 groups in this study. Accoding to coating deposition time(CDT), experimental groups is divided into 6 groups : group A(CDT 30min), group B(CDT 60min), group C(CDT 90min), group D(CDT 120min), group E(CDT 150min), group F(CDT 180min). TiN was coated for the specimens of 6 groups respectively, and those of 1 group as a control group were not coated. TiN coating surface was observed with scratch tester, wear tester, Atomic Force Microscope(AFM), field emission scanning electron microscopy(FE-SEM),. The results were as follows : 1) Adhesion strength for each coated group was increased in proportion to deposition time as shown in table 2. 2) Wear resistance for each coated group are shown in table 3. 3) Surface roughness of each group are shown in Table 4. 4) TiN coated groups show a homogeneous and smooth surface as compared with that of none coated group, however the defects with pore was observed. Conclusively, it is considered that the layer more than 2.1㎛ thickness of TiN coating for abutment screw is necessary.