Surface modification of high-strength aluminium alloy 7075-T6 by plasma electrolytic oxidation (PEO) and type II hard anodization (HA) is presented in the current work. PEO-based ceramic oxide coatings were fabricated by employing an alternating current (AC) power source with a current density of 300 mA/cm². The concentration effect of electrolytes on the alumina coatings was investigated and optimized comprehensively. Three separate aqueous electrolytes with 1:3, 1:1 and 3:1 proportions of sodium silicate (Na₂SiO₃) and potassium hydroxide (KOH) were utilized to evaluate optimum electrolyte concentration for obtaining desired AC-PEO coatings. X-ray diffraction (XRD) was utilized to investigate the phase composition of the coatings. Field emission scanning electron microscopy (FESEM) was employed to investigate the surface and cross-sectional characteristics of oxide coatings. Scratch testing was used to assess the oxide coatings' adhesion ability, and potentiodynamic polarization (PDP) was utilized to assess the coatings' corrosion behaviour in a 3.5 wt% aqueous NaCl solution. Among the AC-PEO and HA coatings, the AC-PEO specimen fabricated with equal ratios of sodium silicate and KOH concentration (Na₂SiO₃:KOH 1:1) showed excellent adhesion strength (critical load, L_c = 41.5 N) along with the remarkable corrosion resistance (corrosion current density, i_corr = 5.63 × 10^–6 mA/cm²).

目前的工作介绍了通过等离子体电解氧化 (PEO) 和 II 型硬质阳极氧化 (HA) 对高强度铝合金 7075-T6 进行表面改性。PEO 基陶瓷氧化物涂层是通过使用电流密度为 300 mA/cm ^{2 的}交流 (AC) 电源制造的。综合研究和优化电解液对氧化铝涂层的浓度影响。三种单独的水性电解质，具有 1:3、1:1 和 3:1 比例的硅酸钠 (Na ₂ SiO ₃) 和氢氧化钾 (KOH) 用于评估获得所需 AC-PEO 涂层的最佳电解质浓度。利用 X 射线衍射 (XRD) 来研究涂层的相组成。场发射扫描电子显微镜（FESEM）被用来研究氧化物涂层的表面和横截面特性。划痕测试用于评估氧化物涂层的附着能力，动电位极化 (PDP) 用于评估涂层在 3.5 wt% NaCl 水溶液中的腐蚀行为。在 AC-PEO 和 HA 涂层中，用等比例的硅酸钠和 KOH 浓度（Na ₂ SiO ₃ :KOH 1:1）制备的 AC-PEO 样品显示出优异的粘附强度（临界载荷，L _c = 41.5 N) 以及显着的耐腐蚀性（腐蚀电流密度，i _corr  = 5.63 × 10 ^–6  mA/cm ²）。