用等通道转角挤压法制备的超细晶铜的腐蚀性能

Corrosion Resistance of Ultra-Fine Grained Copper Prepared by Equal Channel Angle Pressing

超细晶铜具有较高的使用价值,过去对其腐蚀性能研究不多。将工业纯铜退火后,通过等通道转角挤压(ECAP)法挤压成超细晶材料,采用浸泡和电化学方法,结合扫描电镜表面分析技术研究了退火态纯铜和ECAP制备的块体超细晶铜在HCl水溶液中的腐蚀性能。结果表明:用ECAP法制备的超细晶铜结构致密,具有比退火态铜更高的自腐蚀电位和更低的腐蚀电流密度,耐腐蚀性能更强;在不同浓度HCl溶液体系中,超细晶纯铜的失重速率比退火态纯铜小;随着溶液浓度的降低和浸泡时间的延长,超细晶铜和退火态铜的失重速率均减小并趋于稳定;浸泡腐蚀2周后,与退火态铜易发生局部晶间腐蚀相比,超细晶纯铜的均匀腐蚀占主要优势。

The corrosion behaviorof industrially pure annealed copper and ultra-fine grained copper prepared by equal channel angle pressing (ECAP) in the aqueous solution of HI1 was evaluated based on immersion test, electrochemi-cal test, and scanning electron microscopic analysis. Results show that ultra-fine grained copper prepared by ECAP has dense struc-ture. It had a higher corrosion potential, lower current density, and belter corrosion resistance than annealed pure copper. At the same time, the ultra-fine grained copper had a smaller weight loss ratethan annealed copper in HC1 solution with different concentrations. The weight loss rate of both ultra-fine grained copper and annealed copper reduced and stabilized with reducing concentration of HC1 so-lution and extending immersion time. Moreover, after being im-mersed in HC1 solution for two weeks, the annealed copper was dom-inated by local intergranular corrosion, while the ultra-fine grained copper was dominated by uniform corrosion.