Song Si Hoon, Min Bong Ki, Hong Min-Ho, Kwon Tae-Yub
Department of Medical & Biological Engineering, Graduate School, Kyungpook National University, Daegu 41940, Korea.
Center for Research Facilities, Yeungnam University, Gyeongsan 38541, Korea.
Materials (Basel). 2020 Mar 5;13(5):1145. doi: 10.3390/ma13051145.
Titanium nitride (TiN) was deposited on the surface of a cobalt-chromium (Co-Cr) alloy by a hot-wall type chemical vapor deposition (CVD) reactor at 850 °C, and the coating characteristics were compared with those of a physical vapor deposition (PVD) TiN coating deposited on the same alloy at 450 °C. Neither coating showed any reactions at the interface. The face-centered cubic (fcc) structure of the alloy was changed into a hexagonal close-packed (hcp) phase, and recrystallization occurred over at 10 μm of depth from the surface after CVD coating. Characteristic precipitates were also generated incrementally depending on the depth, unlike the precipitates in the matrix of the as-cast alloy. On the other hand, the microstructure and phase of the PVD-coated alloy did not change. Depth-dependent nano-hardness measurements showed a greater increase in hardness in the recrystallization zone of the CVD-coated alloy than in the bulk center of the alloy. The CVD coating showed superior adhesion to the PVD coating in the progressive scratch test. The as-cast, PVD-coated, and CVD-coated alloys all showed negative cytotoxicity. Within the limitations of this study, CVD TiN coating to biomedical Co-Cr alloy may be considered a promising alternative to PVD technique.
通过热壁式化学气相沉积（CVD）反应器在850℃下将氮化钛（TiN）沉积在钴铬（Co-Cr）合金表面，并将涂层特性与在450℃下沉积在同一合金上的物理气相沉积（PVD）TiN涂层的特性进行比较。两种涂层在界面处均未显示任何反应。合金的面心立方（fcc）结构转变为六方密排（hcp）相，并且在CVD涂层后，在距表面10μm深度处发生再结晶。与铸态合金基体中的析出物不同，特征析出物也根据深度逐渐生成。另一方面，PVD涂层合金的微观结构和相没有变化。深度相关的纳米硬度测量表明，CVD涂层合金再结晶区的硬度增加比合金体心处更大。在渐进式划痕试验中，CVD涂层对PVD涂层表现出更好的附着力。铸态、PVD涂层和CVD涂层合金均显示出负细胞毒性。在本研究的范围内，生物医学Co-Cr合金的CVD TiN涂层可被视为PVD技术的一种有前途的替代方案。
