Effects of nickel component,thiourea,glue and chloride ions and their interactions on the passivation of copper–nickel based alloy scrap anodes were investigated by combining conventional electrochemical techniques.R...Effects of nickel component,thiourea,glue and chloride ions and their interactions on the passivation of copper–nickel based alloy scrap anodes were investigated by combining conventional electrochemical techniques.Results obtained from chronopotentiometry and linear voltammetry curves showed that the Ni component made electrochemical stability of the anode strong and difficult to be corroded,caused by the adsorption of generated Cu2O,NiO or copper powder to the anode surface.The Ni2+reducing Cu2+to Cu+or copper powder aggravated the anode passivation.In a certain range of the glue concentration≤8×10–6 or thiourea concentration≤4×10–6,the increase of glue or thiourea concentration increases the anode passivation time.Over this range,glue and thiourea played an adverse effect.The increase of chloride ions concentration led to the increase in passivation time.展开更多
Copper base alloy was overlaid onto 35CrMnSiA steel plate by tungsten inert gas （TIG） welding method. The heat transfer process was simulated, the microstructures of the copper base overlay were analyzed by scanning...Copper base alloy was overlaid onto 35CrMnSiA steel plate by tungsten inert gas （TIG） welding method. The heat transfer process was simulated, the microstructures of the copper base overlay were analyzed by scanning electron microscopy （SEM） and energy dispersive spectrometer （EDS）, and the friction and abrasion properties of the overlay were measured. The results show that the Fe content increases in the overlay with increasing the welding current. And with the increase of Fe content in the overlay, the friction coefficient increases and the wear mechanism changes from oxidation wear to abrasive wear and plough wear, which is related to the size and quantity of Fe grains in the overlay. While with the increase of Fe content in the overlay, the protection of oxidation layer against the oxidation wear on the melted metal decreases.展开更多
A calculation formula of ln γ i 0 for solute element i in liquid alloys was derived by use of free volume theory and Miedema formation enthalpy model. The values of ln γ i 0 of solute elements in liqui...A calculation formula of ln γ i 0 for solute element i in liquid alloys was derived by use of free volume theory and Miedema formation enthalpy model. The values of ln γ i 0 of solute elements in liquid copper at 1273 K were obtained. The results obtained show that the coincidence rate of sign (positive or negative) was 90% for the calculated and experimental values, which were basically in the same magnitude.展开更多
基金Project(51574135)supported by the National Natural Science Foundation of ChinaProject(KKPT201563022)supported by the Collaborative Innovation Center of Kunming University of Science and Technology,China
文摘Effects of nickel component,thiourea,glue and chloride ions and their interactions on the passivation of copper–nickel based alloy scrap anodes were investigated by combining conventional electrochemical techniques.Results obtained from chronopotentiometry and linear voltammetry curves showed that the Ni component made electrochemical stability of the anode strong and difficult to be corroded,caused by the adsorption of generated Cu2O,NiO or copper powder to the anode surface.The Ni2+reducing Cu2+to Cu+or copper powder aggravated the anode passivation.In a certain range of the glue concentration≤8×10–6 or thiourea concentration≤4×10–6,the increase of glue or thiourea concentration increases the anode passivation time.Over this range,glue and thiourea played an adverse effect.The increase of chloride ions concentration led to the increase in passivation time.
文摘Copper base alloy was overlaid onto 35CrMnSiA steel plate by tungsten inert gas （TIG） welding method. The heat transfer process was simulated, the microstructures of the copper base overlay were analyzed by scanning electron microscopy （SEM） and energy dispersive spectrometer （EDS）, and the friction and abrasion properties of the overlay were measured. The results show that the Fe content increases in the overlay with increasing the welding current. And with the increase of Fe content in the overlay, the friction coefficient increases and the wear mechanism changes from oxidation wear to abrasive wear and plough wear, which is related to the size and quantity of Fe grains in the overlay. While with the increase of Fe content in the overlay, the protection of oxidation layer against the oxidation wear on the melted metal decreases.
文摘A calculation formula of ln γ i 0 for solute element i in liquid alloys was derived by use of free volume theory and Miedema formation enthalpy model. The values of ln γ i 0 of solute elements in liquid copper at 1273 K were obtained. The results obtained show that the coincidence rate of sign (positive or negative) was 90% for the calculated and experimental values, which were basically in the same magnitude.
