为研究喷砂酸蚀表面改性方法中酸蚀时间对喷砂后TC4钛合金表面形貌和抗腐蚀性的影响,采用220目的Al_2O_3颗粒对钛合金表面进行喷砂处理,然后对喷砂后的样品在HCl/H_2SO_4混合酸液中分别酸蚀不同的时间(0.5、1、2、3 h),并以抛光组为对照。通过扫描电子显微镜(scanning electron microscopy,SEM)和3D共聚焦显微镜对各组钛片的表面形貌进行表征和表面粗糙度测量。然后运用电化学工作站对各组样品进行耐腐蚀性试验,以评价各组样品的腐蚀行为。试验结果表明,随酸蚀时间的延长,钛合金表面形貌由杂乱趋于均匀化,粗糙度呈现先升后降趋势。2 h时粗糙度达到峰值,表面微孔比例最高,界面扩展面积比达222%。在抗腐蚀性能方面,所有喷砂酸蚀组抗腐蚀性均优于抛光组,表明喷砂酸蚀处理有助于生成腐蚀保护作用更强的氧化膜,且随时间延长,腐蚀倾向减小,3 h时最优。
TCA Titanium plates were etched by HCl/H2SO4 mixture after being blasted by Al2O3 particles of size 220 to investigate the effect of different etching time (0. 5,1, 2 and 3 h) on the surface morphology and corrosion resistance, while the polishing treatment was set as the control group. The surface morphology of the titanium alloy samples was characterized by scanning electron microscopy (SEM) and 3D laser confocal microscopy followed by the surface rough- ness measurement. Then the corrosion resistance measurement was carried out by the electrochemical workstation to evaluate the corrosion behavior of all samples. The results showed that with the prolongation of etching time, the sur- face morphology of titanium alloy tended to be homogenized from clutter, and the roughness first rose and then de- creased. Group 2 h had the maximum roughness and the highest proportion of surface micropores, and the interface ex- pansion area ratio was 222%. In terms of corrosion resistance, all of the sandblasting and acid-etching (SLA) groups performed better than the polishing group, indicating that the SLA treatment can be beneficial for generating oxide film which possesses better corrosion resistance. Besides, with the extending of etching time, the corrosion tendency was smaller, and the group 3 h performed the best of all groups.