铀上激光辅助化学气相沉积镍薄膜研究

Study on Nickel Film on Uranium by Laser Assisted Chemical Vapor Deposition

为防止金属铀的腐蚀,本文采用激光辅助化学气相沉积(LACVD)方法在铀上制备了镍薄膜。采用SEM、XRD分析了薄膜的形貌、物相以及界面特性,采用黏胶拉伸测试表征了膜-基结合性能,采用电化学极化法分析了薄膜的抗腐蚀性能。结果表明:压力和温度对化学气相沉积(CVD)方法制备镍薄膜的质量有较大的影响。随着基底温度和沉积气压的降低,薄膜变得致密、平整,质量提高。在优化的工艺条件165℃、3Pa下,CVD方法所得镍薄膜非常致密。采用LACVD方法时,激光能量为200mJ时所制得的薄膜致密,300mJ时膜变得粗糙。无激光辅助时,CVD方法所制得的薄膜较易剥落,激光辅助下所得薄膜的膜-基结合力较好。LACVD方法大幅提高了薄膜的抗腐蚀性能,抗腐蚀性能的提高主要源于激光辅助使薄膜致密化,提高了薄膜与基底的结合力。

In order to prevent the corrosion of metallic uranium, nickel films were pre- pared on uranium by laser assisted chemical vapor deposition （LACVD） and character- ized by SEM, XRD, gluing pull experiment, and electrochemical polarization. The results show that the pressure of Ni（CO）4 and temperature of substrates have much influence on the quality of nickel films. When the temperature and pressure descend, the films by chemical vapor deposition （CVD） become compact and planar, the quality of the films gets better, and at 165 ℃ and 3 Pa the films show small grain size and high density. By LACVD with 200 mJ pulse energy, films show compact microstructures,and with 300 mJ pulse energy, films become rough. Without laser assistance （CVD） films are easily peeled off from substrate, while the LACVD nickel films show good adhesion. The electrochemical experiments show that uranium with laser CVD nickel films has excellent corrosion resistance. The microscopic analysis shows that corrosion resistance improvement stems from the film density increase and good adhesion of the nickel films and uranium substrate.