摘要
在含三价铬的水溶液中,以氨基乙酸（gly）为配位剂,直流电沉积制备出Fe-Ni-Cr合金箔,研究了电流密度、铬盐浓度对合金箔成分的影响;采用扫描电子显微镜和X射线衍射对合金箔进行表征,并对合金箔的各项性能进行了研究;采用电化学方法对铬电沉积机理进行初探.确定直流电沉积Fe-Ni-Cr合金箔的最佳工艺条件为：电流密度为15A/dm2,铬盐质量浓度为50 g/L,温度为60℃,pH值为1.5.在此条件下可获得厚度为20~30μm光亮、无裂纹的合金箔,其中Cr、Fe和Ni的质量分数分别为4%~6%、60%~65%、30%~35%.合金箔微观形貌为紧密堆砌的不规则板块状小晶粒;合金箔为纳米晶结构,晶粒尺寸在纳米范围内,主相是Cr与α-Fe或γ-Fe形成的间隙固溶体;合金箔中Cr含量提高,硬度、电阻及耐蚀性均随之提高.通过理论计算gly-Cr3＋还原沉积的标准活化能为35.6 kJ/mol,该过程由电子转移步骤控制.
Fe-Ni-Cr alloy foils were electrodeposited from the trivalent chromium bath containing glyeine as complexing agent. The effects of electrodeposition current density and concentration of triva- lent chromium on composition of alloy foil were investigated. The Fe-Ni-Cr alloy foil was characterized by means of SEM（scanning electron microscopy）, EDS（energy dispersive spectraneter） and XRD（X- ray diffraction）. The properties of alloy foil and the mechanism of trivalent chromium reduction were also studied. The optimal process conditions are followed as that： 50 g/L CrC13·6H20, with 15 A/dm2 current density, at 60 ℃ in the solution of pH value 1.5. Fe-Ni-Cr alloy foil with the thickness of 20- 30 μm was obtained with a smooth and uniform appearance, which contains 4%-6% （mass fraction） Cr, 60%-65%Fe and 30%-35%Ni. The results indicated the alloy foil piled up compactly with ir- regular plate grain and its grain size was less than 100 nm; and the main phases were the a-Fe or y-Fe interstitial solid solution with Cr. The higher content of Cr in alloy foil, the higher electrical resistance, micro-hardness and anti-corrosion resistance for alloy foil. Furthermore, the activation energy of electrodeposition Cr was calculated about 35.6 kJ/mol by means of polarization curve, which demonstrates the rate controlled step is charge transfer process.
出处
《纳米技术与精密工程》
EI
CAS
CSCD
2012年第4期291-297,共7页
Nanotechnology and Precision Engineering
基金
湖南省长沙市科技创新基金资助项目
中南大学升华科技创新基金资助项目
关键词
直流电沉积
纳米晶
Fe-Ni-Cr合金箔
机理
direct current electrodeposition
nanocrystalline
Fe-Ni-Cr alloy foil
mechanism
