New Methods For The Components Analysis In Some Hard-to-Analysis Surface Treatment Solution

With the rapid development of science and technology,various machine components,electronic element and devices,etc,they all have strict requirements on their surface characteristics.The various materials need to be technically treated before they are put into use to achieve various characteristics required for product design,such as corrosion resistance,decorative,magnetic,electrical,optical enhancement or anti-reflective,hydrophilic or hydrophobic,heat dissipation or heat insulation,weather resistance properties,and so on.Therefore,surface treatment plays an important role in modern industrial production,technology development and scientific research.The design,preparation and maintenance of surface treatment solution systems are the basis for obtaining good surface properties.The accurate analysis of the content of each component of the solution plays an important role in the correct maintenance and renewal of the bath,and plays an important role in the quality control of the surface treatment process.The purpose of this paper is to investigate and develop some new methods that can meet production requirements,are easy to operate,and cost-effective for some difficult-to-analysis surface treatment solutions for the aviation industry in order to improve the quality and production efficiency of surface treatment products,reduce production costs,save resources,reduce pollution,and meet the requirements of product quality control.It will provide easy-to-use analytical process specifications for enterprises.Based on a detailed analysis of the characteristics of the hard-to-analysis surface treatment solutions,such as alkaline tin plating solution,copper removal solution in chrome plating system,stainless steel pickling and passivation solution,etc.New analytical methods for three kinds of process solutions were investigate based on complexometric titration,redox titration,acid-base titration and ion selective electrode methods.The main research contents are as follows:The machanism and performance of different indicators and different demasking agents in the detection of sodium stannate content and their effects on analytical precision were investigated.The research results indicate: the color-transformation effect of the chrome black T indicator is better than that of the xylenol orange indicator,and the demasking effect of the demaskin agent B is significantly better than that of the demasking agent A.However,both methods can quickly and accuratelymeasure the content of sodium stannate.Through the measurement of the standard recovery test,the error range can meet the technical requirements of the industry enterprise(relative error < 5%).The demasking agent B has higher analytical precision and better ion selectivity,and the demasking agent B is used together with the chrome black T.The relative analysis error is 2.3%,which fully meets the production requirements.In the analysis of the copper removal solution of the chrome plating system,the detection of hexavalent chromium is carried out by ammonium ferrous sulfate titration,and the indicator is sodium diphenylamine sulfonate,which changes the vanadium reagent(N-phenyl o-aminobenzoic acid)which has been used in the past.).During the analysis process,it is not affected by the temperature of the solution.The color transformation effect of the solution at the end of the titration changes from the previous gradual transformation process to the promptly transformation process,and the color change at the end point is more sensitive.In the detection of the total acidity value of the copper-removing solution,an effective adsorbent is used to completely adsorb the hexavalent chromium in the solution,and a certain amount of Ca-EDTA metal ion masking agent is added to mask a small amount of other ions in the solution,and the reaction temperature is controlled in order to completely mask the interfering ions.Finally,the total acidity value of the solution was determined by acid-base titration,and the relative error was 0.8%,which fully meet the production requirements.When measuring the content of nitric acid in the stainless acid pickling and passivation solution,a method for rapid and accurate determination of nitrate was obtained through experimental investigation.The method need to controls the acidity value and temperature of the solution,and then uses sodium diphenylamine sulfonate as an indicator,and the titration reagent is a potassium dichromate standard solution.This method is very suitable for actual production and easy to operate.In the measurement of fluorine content,a new type of precipitant was used.In the first stage of the measurement,the reaction coefficient H value and W value of the prepared solution were first measured.The xylenol orange was selected as the indicator,and the re-titration test solution was the EDTA standard solution.After the standard recovery test,the recovery rate is 99.64%,the relative error of measuring nitric acid was 0.36%.This method is applicable to a variety of stainless pickling solutions,and can replace the radioactive thorium nitrate detection method used in the past,avoiding the healthhazard to analysts.Through detailed and in-depth research and exploration,the experiment achieved good results and three new analysis standards were established for the chemical analysis of surface treatment solution for aviation industry companies,which improved the analysis accuracy and ease of operation.