title: A graded nano-TiN coating on biomedical Ti alloy: Low friction coefficient, good bonding and biocompatibility.
abstract: In order to solve wear resistance of Ti alloy biomaterials, the concept of a graded nano-TiN coating has been proposed. The coating was prepared on Ti-6Al-4V bio-alloy by DC reactive magnetron sputtering. The wear performance of the coated specimens was measured in Hank's solution under the load of 10N, and the biocompatibility was evaluated according to ISO-10993-4 standard. The results show that the gradient coating exhibits a gradual change in compositions and microstructures along the direction of film growth. Nano-TiN with the size of several to dozens nanometers and Ti4N3-xtransitional phase with variable composition form a graded composite structure, which significantly improves adhesion strength (Lc1=80N, Lc2=120N), hardness (21GPa) and anti-wear performance (6.2×10-7mm3/Nm). The excellent bonding and wear resistance result from a good match of mechanical properties at substrate/coating interface and the strengthening and toughening effects of the nanocrystalline composite. The nano-TiN coating has also been proved to have good biocompatibility through in-vitro cytotoxicity, hemocompatibility and general toxicity tests. And thus, the proposed graded nano-TiN coating is a good candidate improving wear resistance of many implant medical devices.
authors.affiliation: Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Material Science and Engineering, Northeastern University, Shenyang 110819, China.
authors.forename: Wenfang
authors.initials: W
authors.lastname: Cui
authors.affiliation: Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Material Science and Engineering, Northeastern University, Shenyang 110819, China. Electronic address: qingw@smm.neu.edu.cn.
authors.forename: Gaowu
authors.initials: G
authors.lastname: Qin
authors.affiliation: Spinal surgery, Shengjing Hospital, China Medical University, Shenyang 110004, China.
authors.forename: Jingzhu
authors.initials: J
authors.lastname: Duan
authors.affiliation: Spinal surgery, Shengjing Hospital, China Medical University, Shenyang 110004, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Wang
mesh_terms: D000497:Alloys; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D017276:Friction; D014025:Titanium / Q000737:chemistry*
chemical_list: D000497:Alloys; D020099:Coated Materials, Biocompatible; C031462:titanium alloy (TiAl6V4); C041500:titanium nitride; D014025:Titanium
keywords: Biocompatibility; Biomedical Ti alloy; Mechanical properties; Nano-TiN coating; Wear