涂层与块体致密度差值对铁基非晶合金耐蚀性的影响  

Effect of relative density difference between coating and bulk on Fe-based amorphous alloys corrosion resistance

作　　者：陈庆军[1] 蒋薇[1] 高霁雯[2] 

机构地区：[1]南昌航空大学材料科学与工程学院,南昌330063 [2]南昌航空大学土木建筑学院,南昌330063

出　　处：《中国有色金属学报》2015年第9期2414-2420,共7页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(51261021);江西省科技落地计划资助项目(KJLD13056)

摘　　要：制备Fe41Co7Cr15Mo14C15B6Y2块体非晶合金与非晶合金涂层,通过化学腐蚀浸泡法分析两者腐蚀前后的相对表面功函数,从而研究两者致密度差值对耐蚀性的影响。采用动电位极化曲线结合交流阻抗测试分析涂层与块体在0.5 mol/L H2SO4溶液中的电化学腐蚀特性,进一步得到孔隙在腐蚀过程中的作用。结果表明:块体非晶的自腐蚀电位高于涂层的,其电流值比涂层的小一个数量级,其拟合电路为R(QR)型;由于孔隙及表面钝化膜等影响因素的存在,涂层的拟合电路为(R(Q(R(QR)))型。通过电子探针实验得出涂层与块体存在9.25%的孔隙率差值,导致了50 me V的功函数差值。孔隙尺寸越大、数量越多则合金耐蚀性越差。腐蚀前后块体非晶合金的功函数值都比涂层的高,且表现出更强的耐蚀性。Fe41Co7Cr15Mo14C15B6Y2 bulk amorphous alloys and amorphous coating alloys were prepared, and the effects of both density difference on the corrosion resistance were investigated by analyzing the relative surface work function of samples before and after chemical corrosion. The role of porosity in the corrosion process can be obtained by analyzing electrochemical corrosion characteristic of coating and bulk alloys in 0.5 mol/L H2SO4 solution based on the driven potential polarization curves and AC impedance measurement. The results show that the corrosion potential of coatings alloys is higher than that of bulk alloys, the current value of bulk alloys is one order magnitude smaller than that of coatings alloys, and the fitting circuit of bulk alloys is R （QR） type. Because of the influence of porosity and surface passivation film, the fitting circuit of the coating alloys is （R（Q（R（QK））） type. The electron probe experimental results show that the porosity difference of coating and bulk alloy is 9.25% which leads to the work function difference of 50 meV. The pore size is bigger and the pore number more, the corrosion resistance of alloys is worse. Both before and after corrosion, the work function of the bulk amorphous alloy is higher than that of the coating alloys, showing the bulk amorphous alloy has stronger corrosion resistance.

关 键 词：铁基大块非晶合金 铁基非晶涂层 致密度 相对表面功函数 耐蚀性 

分 类 号：TG178[金属学及工艺—金属表面处理]