Gr/6061 Al复合材料环保型稀土耐蚀膜的研究

Study of Environment-Friendly Rare Earth Conversion Coating for Corrosion Resistance on Gr/6061 Al Composites Surface

随着铝基复合材料的应用范围不断扩大,对其腐蚀性能方面的要求也更加迫切。传统铬酸盐钝化的方法因含有毒性的六价铬离子并致癌将被废除,因此开发绿色环保耐腐蚀涂层是当今材料研究领域的热点之一。采用含稀土Ce钝化防腐蚀膜层的工艺提高Gr/6061Al复合材料的耐腐蚀性,膜层无毒、无污染,具有环境保护作用。文章对环保型稀土Ce耐蚀膜的成膜工艺进行了研究,此工艺在Gr/Al复合材料表面覆盖完整,呈现"干泥"状分布于Gr/Al复合材料表面。EDS面扫描结果认定稀土Ce含量达47.48%(质量分数),Ce、O、Si、Al是组成膜的主要元素,膜层主要由稀土氧化物或氢氧化物组成。防腐蚀性测试表明,稀土转化膜试样的E_(corr)比裸试样的E_(corr)提高84 mV,说明稀土转化膜试样的防腐蚀性能较佳。无毒无污染的Gr/Al复合材料表面环保型稀土Ce转化膜是有希望进行工业化应用的理想涂层。

Currently, the demand of corrosion resistance for aluminum matrix composites is imminence along with its application expanding. Intensive research has been undertaken aimed at finding non-contaminating alternatives for surface treatment processes based on the use of chromates. One of the alternatives proposed involves the use of rare earth Ce which is environment-friendly. In the study on the process of treatment on Gr/6061Al composites sample, the coating is non-toxic and non-pollution. These results indicate that the graphite fibers and aluminum alloys surfaces both coated on Ce conversion coatings; the micro-structure of coating is dried-mud-like. The energy dispersive spectroscopy （EDS） plane scanning analysis indicated that the major elements in the coating were Ce, O, Si, Al and the Ce content, which reached 47.48 wt%. The Ce conversion coatings increased the corrosion resisting properties of Gr/6061Al composite, with a higher free corrosion potential （Ecorr） for the coated composite than those of the bare composite, and the △Ecorr is 84 mV. The environment-friendly Ce coating on the Gr/6061Al composite surface has been necessary to develop feasible treatments for industry.