制备工艺参数对AZ31镁合金表面溅射TiAlN薄膜耐腐蚀性能的影响

Deposition and Corrosion Resistance of TiNAl Coating on AZ31 Mg Alloy Substrate

采用射频反应磁控溅射法在AZ31镁合金表面沉积了TiAlN薄膜。用场发射扫描电镜、电化学工作站研究分析了薄膜的表面形貌以及电化学性能,研究了铝靶溅射功率、钛靶溅射功率、氮气流量、沉积时间对TiAlN薄膜耐腐蚀性能的影响。结果表明实验所制备的TiAlN薄膜表面光滑、致密。当Al靶功率为50 W,Ti靶功率为125 W,N2流量为30 mL/min(标准状态),沉积时间为8 h时薄膜耐腐蚀性能最佳。薄膜腐蚀电流密度(4.321×10-7 A/cm2)比镁合金基体(1.066×10-5 A/cm2)降低了1个数量级以上,镁合金耐腐蚀性能得到较大提高。

The TiNAl coatings were deposited by RF rnagnetron sputtering of multi-target on substrate of AZ31 Mg alloy. The impacts of the deposition conditions, including the sputtering power, deposition rate and time, N2 flow rate, on the microstmctores and mechanical properties of the coatings were evaluated. The TiNM coatings were characterized with field emission scanning electron microscopy（FE-SEM）, and electrochemical probe. The results show that the compact, smooth and uniform TiNAl coatings display much higher corrosion resistance, synthesized under the optimized conditions： the Al and Ti targets sputtered at 50 W,and 125 W, respectively; a N2 flow rate of 30 mL/min, and a deposition time for 8 h.The corrosion current density of the TiNM-coated AZ31 Mg alloy decreased from 1.066 × 10^-5 A/cm^2 of the control sample to 4.321 × 10^-7 A/cm^2,a reduction of more than one order of magnitude.