超声波功率对电沉积钴-镍-钨合金性能的影响

以纯铜为基体,在100 kHz频率的超声波辅助下电沉积Co-Ni-W合金镀层。镀液组成和工艺条件为:CoSO4·7H2O 0.6 mol/L,NiSO4·6H2O 0.2 mol/L,Na2WO4·2H2O 0.18 mol/L,H3BO30.2 mol/L,Na2SO4·10H2O 0.05mol/L,Na3C6H5O7·2H2O 0.4 mol/L,pH 6.0,温度(40±2)℃,电流密度0.6 A/dm2,超声波功率0~750 W,时间15 min。研究了超声波功率对电沉积过程及合金镀层表面形貌、元素组成、相结构、显微硬度和耐蚀性的影响。结果表明:超声波辅助可削弱电沉积过程中浓差极化的影响,强化液相传质,促进反应界面的电子转移。超声波功率高于150W时,Co-Ni-W合金镀层的W原子分数显著提升。超声波功率为300~600W时,镀层平整、致密,呈纳米晶结构。超声波功率≥600W时,镀层趋于非晶态结构。超声波功率为450~600W时,Co-Ni-W合金镀层具有较高的显微硬度和良好的耐蚀性。

Study on Transport of Oxygen Through CaO-MgO-Al_2O_3 Slag From Molten Ultra-Low Carbon Steel by Chronoamperometry

The deoxidization reaction at the interface between slag and metal is one of the most important reactions in the iron and steel making.The interface reaction and transport characteristics of Molten Ultra-low Carbon Steel with CaO-MgO-Al2O3slag system under different over potential conditions of the system was studied.The electrochemical reduction mechanism at the interface between the molten slag and molten steel was investigated.The results showed that Chronoamperometry method is very useful for the study of interfacial reaction in the slag-metal system.The current of interfacial reaction decreases approximately linearly with t-1/2,and the diffusion coefficient of oxygen in molten slag calculated by Cottrell equation increased dramatically with over potential.In the open circuit potential,the diffusion coefficient of oxygen in the slag is about 10-8m2/s.