Fatigue durability and corrosion resistance of TiO2 films on CoCrMo alloy under cyclic deformation
Fatigue durability and corrosion resistance of TiO2 films on CoCrMo alloy under cyclic deformation
复制标题
DOI：
10.1016/j.surfcoat.2015.05.010
复制
发表时间：
2015-08
影响因子：
5.4
通讯作者：
D. Xie;Haihua Wang;R. Ganesan;Y. Leng;Hong Sun;N. Huang
中科院分区：
文献类型：
--
作者：
D. Xie;Haihua Wang;R. Ganesan;Y. Leng;Hong Sun;N. Huang
采用高功率脉冲磁控溅射法（HiPIMS）在CoCrMo基片上制备了厚度分别为45 nm和300 nm的光滑和致密的TiO2薄膜。采用悬臂梁共振法对TiO2薄膜进行循环应力加载，研究了TiO2薄膜的疲劳寿命。同时研究了在TiO2薄膜中有意引入的预裂纹的演化过程。通过动电位极化曲线研究了TiO2涂层CoCrMo合金在循环变形后的耐蚀性能。结果表明，在1.08 × 107次载荷循环和最大应力为200 MPa时，两种膜均未出现剥离、开裂或分层现象。对于较厚的TiO2膜（300 nm）中的预裂纹的演化，在膜中的预裂纹附近出现新的裂纹，而对于较薄的TiO2膜（45 nm）中的预裂纹，没有观察到任何新的裂纹。较薄的膜似乎比较厚的膜显示出更好的疲劳耐久性。动电位极化测试表明，在最大应力为20 MPa、1.08 × 107次循环后，较薄的TiO2薄膜（45 nm）的耐蚀性没有下降。
Smooth and dense TiO2films with different thickness (45 nm and 300 nm respectively) were deposited on a flat CoCrMo substrate by high power impulse magnetron sputtering (HiPIMS). A cantilever resonance method was developed to load cyclic stress on the sheet samples to investigate the fatigue durability of the TiO2films. The evolution of pre-cracks, which were introduced intentionally in the TiO2films, was studied at the same time. After cyclic deformation, the corrosion resistance of the TiO2film coated CoCrMo alloy was investigated by potentiodynamic polarization tests. The results showed that there were no peelings, cracks or delamination of both film types after 1.08 × 107loading cycles with the maximum stress of 200 MPa. For the evolution of the pre-cracks in the thicker TiO2films (300 nm), new cracks emerged near the pre-cracks in the films, while for the pre-cracks in the thinner TiO2films (45 nm) not any new cracks were observed. The thinner films seemed to show better fatigue durability than thicker films. The potentiodynamic polarization tests revealed that the corrosion resistance of the thinner TiO2films (45 nm) was not degraded even after 1.08 × 107loading cycles with the maximum stress of 20 MPa.