The Effect Of Current Density And Electric Field On Ni And Its Alloy Electrodeposition For Copper Crystallizer

Crystallizer is a key component in the cast of slab mould, its performance has great impact on surface quality of slab mould and production efficiency. Shanghai Baosteel Equipment Maintenance Company has the biggest yield of copper crystallizer electrodeposit in China, but its production efficiency can't satisfy the demand of client, production capacity isn't exerted adequately, so increasing the current density of electroplating and improving production efficiency have great significance. Furthermore, a lot of metal resource such as Ni and Co is consumed on the assistant cathode in the process of electroplating, it's a severe waste. So device of new kind of assistant cathode equipment to reduce waste has great practical significance.The effects of current density on the performance of Ni and its alloy coatings were researched detailedly. Microhardness instrument, microscope, roughness instrument, copper coulomb and micrometer were used to test the coatings. The results showed that after current density increased of 10% for Ni and Ni-Fe from sulphamate electrolyte and 5% for Co-Ni from vitriolic electrolytes, the performance of 3 coatings changed little, only thickness uniformity of coatings had obvious change, 3 coatings declined 19%, 22% and 66% respectively. The EDS results showed that the content of Fe increased in Ni-Fe alloy coating and Co-Ni alloy coating had no change. The results of XRD showed that there were no change in crystal parameters and grow orientation of coatings following the increase of current density. All of these results showed that the increase of current density had feasibility.The effects of electric field factors including the proportion of cathode and anode, the distance of cathode and anode, assistant cathode and cathode shield equipment and whip intensity on the performance of coatings were researched. The results showed that the effects of electric field factors centralized on thickness uniformity of coatings too. Some methods such as keep the proportion of cathode and anode as 1.1~1.2, increase the distance of cathode and anode by 20%, applying electric assistant cathode and cathode shield equipment were all propitious to uniform thickness of coating. Increase of whip intensity could improve the performance of coating.ANSYS of FEM (Finite Element Method) package was applied in research electric field of cathode and anode in electroplating bath for the first time and the results of ANSYS were corroborated by experiment. The effects of some electric field factors such as assistant cathode and the shape of cathode ect on the distributing of electric field in electroplating bath were researched by ANSYS. The FEM model of Baosteel's electroplating bath was established to find a new type cathode shield equipment that could be applied industrially finally.