[15a-A408-1~10] 6.2 Carbon-based thin films

▲ [15a-A408-2] Influence of negative bias voltages on mechanical and structural properties of nanodiamond composite films on Ti substrates

〇(D)Lama Osman Mohamed^1,2, Abdelrahman Zkria^1,2, Ali M Ali^1,3, Hiroshi Naragino¹, Tsuyoshi Yoshitake¹ (1.Department of Applied Science for Electronics and Materials, Kyushu University, Fukuoka 816-8580, Japan, 2.Department of Physics, Faculty of Science, Aswan University, Aswan 81528, Egypt, 3.Department of Physics, Faculty of Science, Al-Azhar University, Cairo 11884, Egypt)

Keywords:Nanodiamond composite films, Ti substrates, Negative bias

Pure titanium (Ti) has been widely utilized biomaterial that requires a highly protective coating to enhance its longevity as an implant or artifical joint within a human body. Owing to a tribocorrosion endurement, the lifespan of such Ti biomaterials is limited and patients are subject to painful revison surgeries. In the same regard, nanodiamond composite coatings (NDC) offer the perfect match for boosting Ti implant’s lifetime as they provide extremmely smooth surfaces, high hardness, wear and corrosion resistance. However, NDC coating’s adhesion to Ti is a dilmmea due to a native oxide layer (TiO2). Commonly, NDC films has ever been deposited on Ti by chemical vapor deposition (CVD) that includes high substrate temperatures 1000°C which are sufficient to eliminate this surficial (TiO2) layer. Nevertheless, due to a large mismatch in thermal expansion coefficients of NDC films and Ti, a major internal stress is formed and peeling off can occur. In our previous work, we reported a novel adhesion (16N) of hard NDC films (54GPa) on Ti substrates at room temperature via hybrid ion etching gun (IG) and coaxial arc plasma deposition (CAPD). These impressive results motived us in this work to improve,study and optimize the mechanical and structural properties of the obtatined NDC films on Ti by varying substrate negative bias voltages via IG/CAPD.