Al-Cr涂层低温扩散制备及其相组成的研究  

Al-Cr COATINGS PREPARED BY DIFFUSION AT LOW TEMPERATURE AND ITS PHASE CHARACTERIZATION

作　　者：李文川[1] 蔡俊[1] 凌国平[1] 

机构地区：[1]浙江大学材料科学与工程系,杭州310027

出　　处：《金属学报》2011年第2期231-235,共5页Acta Metallurgica Sinica

摘　　要：通过水溶液镀Cr后再用AlCl_3 EMIC(氯化1-甲基3-乙基咪唑)离子液体镀Al,制备Cr/Al复合镀层,其后通过低温扩散热处理制备Al-Cr涂层.用OM,SEM,BSE,EDS和XRD研究了短时间热处理时,热处理温度对Al-Cr涂层组成和结构的影响.结果表明,Cr/Al复合镀层在540℃时即可发生明显的互扩散,形成Al-Cr合金层.通过对复合镀层中Cr和Al镀层厚度的控制,可以得到不同组成的Al-Cr合金涂层.6.5μm Cr/15μm Al的复合镀层经640℃/960 min热处理,表面形成以Al_8Cr_5为主的合金涂层;1.6μm Cr/15μm Al的复合镀层经600℃/30 min热处理,可得到以Al_4Cr为主的Al-Cr涂层.ABSTRACT The A1-Cr coating exhibits a good steam oxidation resistance and can act as tritium permeation barrier. It is necessary to prepare A1-Cr coating at low temperatures to avoid detrimental effect on the mechanical properties of the substrate. In the present study, a new process was proposed to prepare A1-Cr coating by electrodeposition of Cr/A1 composite coatings firstly, and then heat treatment at low temperatures. The Cr/A1 composite coatings were obtained by electrodepositing Cr from aqueous solution followed by electrodepositing A1 from A1C13-EMIC ionic liquid. Effects of the temperature of heat treatment on the composition and phase of alloy layers were studied by using OM, SEM, BSE, EDS and XRD. The results showed that an A1-Cr alloy layer at the Cr/A1 interface was formed even at low temperature of 540 ~C by the interdiffuse between A1 and Cr coating. The different A1 Cr alloy layers could be formed by controlling the thickness of Cr and A1 in Cr/A1 composite coatings. For 6.5 #m Cr/15 #m A1 composite coating, the main phase was AlsCr5 for 960 rain heat treatment at 640℃, and for 1.6 μm Cr/15/tin A1 composite coatings treated at 600℃ for 30 min, the main phase of alloy layer was Al4Cr.

关 键 词：Al-Cr涂层 离子液体 镀Al 热处理 

分 类 号：TF777.1[冶金工程—钢铁冶金]