Study On Preparation Process Of Nickel-based X-ray Grazing Incident Mirror

The X-ray optical lens composed of nested grazing incidence mirrors is one of the core components of the X-ray telescope system.The nested grazing incidence mirror is generally a thin-walled structure with a sub-millimeter thickness.It is easily deformed under the action of external force.The traditional grinding and polishing process is difficult to process.It is usually manufactured by copy molding,that is,transferring the high-precision mold surface shape.Therefore,area transfer technology is the key to manufacturing nested X-ray grazing incidence mirrors.For the preparation of cylindrical X-ray grazing incidence mirrors,the paper proposes a manufacturing method based on chemically deposited nickel-phosphorus alloys.Compared with the existing nested mirror electroforming nickel manufacturing process,the chemical deposition method is simple in process and the coating thickness is uniform.The stress can be controlled to obtain a nickel-based nested mirror with better performance.The thesis systematically elaborated the realization principle,technological composition and key technologies of chemically deposited nickel-phosphorus alloy According to the structural characteristics of the nested mirror,the manufacturing process of the nested mirror was formulated.Electroless nickel-phosphorus alloy technology can be roughly divided into three technical links:pre-treatment,chemical deposition and post-treatment.The thesis has carried out adequate experimental verification of the key processes of each link,and further optimized the process data.Through a series of process experiments,the relationship between the phosphorus content of the nickel-phosphorus coating and the chemical composition of the plating solution such as the main salt,reducing agent,and complexing agent was clarified.At the same time,the pH,temperature,and stirring state of the plating solution were analyzed for chemical deposition.The impact of craftsmanship.By adjusting the parameters such as the amount of main salt and reducing agent,and the type of preferred complexing agent,the technical indicators such as the deposition rate and phosphorus content of the nickel-phosphorus alloy coating were controlled.Finally,citric acid and sodium citrate were selected as complexing agents.Good deposition speed,and easy to control the phosphorus content in the coating;the use of potassium iodate and thiourea improves the stability of the plating solution and prolongs the service life of the plating solution;too low pH value lowers the deposition rate,too high affects the plating The stability of the bath,the impact of the change on the phosphorus content is more critical;within the suitable working temperature range,the deposition rate is approximately proportional to the temperature,and the temperature difference has little effect on the performance of the coating;stirring can ensure that the concentration distribution of the bath is uniform and accelerating the reaction gas to detach from the surface of the coating,so that the nickel-phosphorus coating is uniform,and there are no defects such as pores on the surface.Based on the experimental data,the paper built a set of automated equipment for the chemical deposition of nickel-phosphorus alloys,and completed the preparation of a nickel-phosphorus coating.The thickness of the coating is uniform and flat,the internal stress is small,the surface is clean and dense,no pores and pits,etc.Good corrosion resistance,basically meet the requirements of use.The experimental results show that the developed chemical deposition process has a high degree of automation;the nickel-phosphorus deposition rate is moderate;the composition of the plating solution is simple,the stability is good,and it is easy to maintain,which can meet the continuous production needs of small batches of nested mirrors.