等离子电解氧化脉冲电压对铝合金陶瓷层结构的影响

Effect of Pulse Voltage in Plasma Electrolytic Oxidation on Structure of Ceramic Coatings on 2024 Aluminium Alloy

在富含超细SiC粉末的电解液中,采用等离子电解氧化技术在铝合金表面生成耐蚀陶瓷膜,系统分析了脉冲电压对陶瓷膜厚度、生长动力学、组织结构和耐蚀性的影响。结果表明,在脉冲电压低于400 V时,随着脉冲电压的升高,陶瓷膜的厚度呈现缓慢增加趋势,电压低于400 V和高于400 V时出现不同的电流-时间变化曲线。随着脉冲电压的上升,陶瓷膜出现三种不同的组织结构,而且在NaCl溶液中显示出不同的耐蚀性。

Ceramic coatings on the surface of 2024 alloy were prepared by plasma electrolytic oxidation（PEO） in the electrolyte solution rich in ultra-fine SiC powder. The effects of the pulse voltages on the thickness, growth mechanism, structures and corrosion behavior of coatings were systematically discussed. The results show that the thickness of the ceramic film increased slowly with increasing the pulse voltage, when the pulse voltages were lower than 400 V. The current density-time curves were very different when the pulse voltages were lower than 400 V and higher than 400 V. With the increase of the pulse voltages, three different surface morphologies of ceramic coatings were formed, and they exhibited different corrosion potentials and current densities in 3. 5% NaC1 solution.