脉冲电沉积纳米晶铁-镍-铬合金箔工艺与性能研究

采用脉冲电沉积方法从含三价铬镀液中制备出铁-镍-铬合金箔,通过正交试验优化工艺条件,探究了配位剂和温度对合金箔成分的影响。采用扫描电镜(SEM)、能谱(EDS)、X射线衍射(XRD)对合金箔进行表征,并对合金箔的电性能、力学性能和抗腐蚀性进行研究,采用电化学手段对合金电沉积机理进行初探。获得最优工艺为:CrCl3·6H2O50g·L-1,电流密度16A·dm-2,周期100ms,占空比0.3,温度60℃,pH1～1.5,沉积45min可获得厚度为20～30μm的合金箔,此合金箔成分质量分数为:(62～67)%Fe、(30～33)%Ni和(3～5)%Cr。电沉积Fe-Ni-Cr合金箔微观为紧密堆砌的球形,无微裂纹,晶粒尺寸在纳米范围内,主相结构为Cr与α-Fe或γ-Fe形成的固溶体,当Cr含量4%,基体主要为γ-Fe;最佳工艺条件下获得的合金箔电阻率为68.66×10-6A·cm,具有良好的电性能;显微硬度为5819MPa(HV);在3.5%NaCl中腐蚀电流密度仅为1.685×10-6A·cm-2,抗腐蚀性优良;配位剂的加入使得铁、镍、铬的合金沉积电位接近,合金沉积变为可能。

Study of Technology and Properties for Pulse Electrodeposition Nanocrystalline Fe-Ni-Cr Alloy Foil

Fe-Ni-Cr alloy foil was pulse electrodeposited from the trivalent chromium bath.Orthogonal design was used to optimize the processing parameters.The effects of the electrodeposition parameters such as complexing agent and temperature on the composition of alloy foil were investigated systematically.The Fe-Ni-Cr alloy foil was characterized by SEM,EDS and XRD.The optimal process conditions are followed as that:50 g·L-1 CrCl3·6H2O,with 16 A·dm-2 current density,the period with 100 ms,the duty cycle with 0.3,at 60 ℃ temperature in the solution of pH 1～1.5 with 45 minutes electroplating.The 20-30 μm thick Fe-Ni-Cr alloy foil with a smooth and uniform appearance was obtained,which contains(62～67)wt% Fe,(30～33)wt%Ni and(3～5)wt% Cr.The results indicate the alloy foil is piled up compactly with sphericity and its grain size less than 100 nm;and the main phases are the α-Fe or γ-Fe solid solution with Cr.When Cr content exceeds 4wt%,the main phase would be γ-Fe.The alloy foil also exhibits better electrical,mechanical performance and corrosion resistance with 68.66×10-6 Ω·cm resistivity,5819 MPa micro-hardness and 1.685×10-6A·cm-2 corrosion current density in 3.5%NaCl solution respectively.Furthermore,the mechanism of co-deposition Fe-Ni-Cr was studied by means of polarization curve and cyclic voltammetry.The results demonstrate that the complexing agent changes the deposited potential of Fe,Ni,Cr,respectively and makes the co-deposition possible.