The Study Of EPE Serie Additive Of Methanesulfonic Acid High Speed Tin Plating System

Tin plating can be divided into alkaline tin plating and acidic tin plating.Among them,the tin plating in the methane sulfonic acid system has the advantages of nontoxicity,low porosity,corrosion resistance,fine and smooth plating,etc.Alternatives to other tin plating methods,the tin plating in the methane sulfonic acid system has been developed more quickly.High-speed strip plating is a typical application of methanesulfonic acid tin plating.The current research is mainly focused on the development of additives.The high-speed tin plating additives are monopolized by foreign countries.The common types of additives include: polyethylene glycol,polypropylene glycol and other alcohol ethers,polyoxyethylene ether polyethers,and polyoxyethylene oxypropylene block polyethers.This article attempts to develop additives with independent intellectual property rights,obtain high-speed corrosionresistant tin coating in high-speed steel strip,provide data support and guidance for localization,and promote the development of high-speed tin plating technology.In this paper,the additives of methanesulfonic acid electroplating tin system are mainly optimized,and the deposition process is studied.Electrochemical work station,static Hull cell,high-speed Hull cell,SEM,XRD and other methods were used to determine the additives and process parameters of high-speed electroplating of tin,and the plating solution and coating properties of the bath were investigated.By studying the effects of methane sulfonic acid and stannous methane sulfonate on the performance of the tin plating solution,the basic formulation of the tin sulphonic acid solution was determined to be 15g/L Sn2+,45 m L/LMSA.Through the accelerated air oxidation experiment,1g/L~15g/L concentration of hydroquinone can be used to make the methanesulfonic acid tin plating solution have good stability.Through the cloud point test,surface tension test,Hull cell experiment,electrochemical test and SEM method,the tin plating additives of the methanesulfonic acid system were EPE-1,EPE-2 and EPE-7.The effect of additive concentration and compound additives on electroplating tin was studied.The concentrations of EPE-1,EPE-2,and EPE-7 were respectively 1g/L,0.5g/L,0.5g/L,and when 0.5g/L EPE-1 was mixed with 1g/L EPE-2,the tin plating layer all have good performance.The compounding additive process has a current density of 0.5A/dm2~3A/dm2 and a temperature of 40°C~60°C.Comparing the effects of compounding additives and commercially available additives on the performance of the plating solution and the coating,the current efficiency of adding the tin additive solution of the compound additive at a current density of 4A/dm2 is about 77%,and the current efficiency of adding a commercially available additive plating solution is only 50%.Electrochemical methods and salt spray tests showed that the tin corrosion resistance of the compounded additives was better than that of commercially available additives.The EPE-1,EPE-2,and EPE-7 additives selected in the static experiments were again optimized by high-speed Hull cell,SEM,and XRD experiments to be suitable for MSA high-speed tin plating.Studies have found that when the high-speed plating flow rate reaches a turbulent flow state,the allowable cathode current density during plating can be significantly improved.High-speed Hull cell and SEM methods were used to study the influence of flow rate,temperature,and current density on electroplating tin,and the formula and process of high-speed tin-plating additives were determined.The influence of each additives on the performance of the coating compared with commercially available additives were studied and finally optimized.EPE series MSA high speed tin additive formula is: 0.5g/L EPE-2,plating process is temperature 20°C~60°C,plating speed >146cm/s,current density 10A/dm2~40A/dm2;besides,adding 0.5g/L EPE-1,1g/L EPE-2,1g/L TP-G7 compound additives to the tin plating solution could get the best corrosion resistance tin plate,also has a good application in high-speed plating tin plating solution.