磷酸铝铬封孔处理对热喷涂WC-12Co涂层耐蚀性的影响

发布时间：2018-03-20 23:21

  本文选题：磷酸铝铬　切入点：封孔剂　出处：《中国表面工程》2017年04期 　论文类型：期刊论文

【摘要】：以磷酸铝铬溶液和Cr_2O_3粉末为原料制备了一种封孔剂,并对WC-12Co热喷涂涂层进行封孔处理。利用XRD、SEM、EDS以及TG-DSC分别对磷酸铝铬的物相、封孔前后涂层表面形貌、固化特性和耐热性能进行检测分析。利用动电位极化电化学测试和热震试验分别对封孔前后涂层的抗腐蚀性和固化后的磷酸铝铬层的抗热震性能进行研究。结果表明:磷酸铝铬的固化温度在250℃左右,在700℃内体系无任何热效应发生,材料具有良好的耐热性能。固化后涂层表面致密,磷酸铝铬对涂层孔隙具有良好的填充作用,明显降低了涂层的孔隙率。封孔后的涂层具有较高的自腐蚀电位和较小的腐蚀电流密度,涂层耐蚀性显著提高。在450℃下进行热震试验,当热震次数一定时(热循环100次),添加填料的磷酸铝铬层的剥落面积低于未添加填料的磷酸铝铬层,表现出较高的抗热震性能。
[Abstract]:A kind of sealing agent was prepared by using aluminum chromium phosphate solution and Cr_2O_3 powder as raw materials, and WC-12Co thermal sprayed coating was treated by pore sealing. The phase of aluminum chromium phosphate and the surface morphology of the coating before and after sealing were determined by XRDX SEMEDS and TG-DSC, respectively. The corrosion resistance of the coating before and after sealing and the thermal shock resistance of the solidified aluminum chromium phosphate coating were studied by potentiodynamic polarization electrochemical test and thermal shock test respectively. The results show that the curing temperature of chromium aluminophosphate is about 250 鈩，

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