Thread Content
Preface: The process formulation and applications for bright nickel plating at room temperature are essentially the same as those for heat-assisted nickel plating; only heating is no longer required, and it can be used at room temperatures that are not lower than a certain threshold. Since heating is not required, it not only saves the fuel used as a heat source, but more importantly, it prevents the decomposition of organic additives in the solution whose thermal stability is poor due to heating; such decomposition would generate impurities that affect the quality of the coating and pose difficulties in the maintenance and management of the solution. In accordance with the standards set by the Ministry of Health, the products manufactured by our factory are made from steel or copper components, and are coated with nickel through a process that involves dark nickel plating followed by bright nickel plating. Strict requirements are imposed on the adhesion strength of these coatings; before switching to a bright nickel plating process at room temperature, peeling of the coating often occurred. After visiting various factories and repeating the treatment of the plating solution, no significant improvement was achieved, which at one point affected the completion of production tasks. By switching to the normal-temperature bright nickel plating process, the rework caused by poor adhesion of the coating was largely resolved. I. Formulation process conditions and procedure: Formulation – Nickel sulfate: 1 gram per liter; Nickel chloride: 1 gram per liter; Boric acid: 1 gram per liter; Magnesium sulfate: 1 gram per liter; Extender: 1 gram per liter; Butyrdiol: 1 gram per liter; Sodium dodecyl sulfate: 1 gram per liter. Centiliter. Working conditions: 2, 1. Cathode current density: 1 ampere per decimeter. Temperature: above a certain value. Cathode movement: lateral movement once. Taking carbon steel surgical instrument products as an example in the manufacturing process: chemical degreasing, cleaning with copper wire wheels and water, electrochemical degreasing, etching with hydrochloric acid, etching with sulfuric acid, washing, plating with dark nickel, plating with bright nickel, washing after plating, and then plating with chromium. II. Bath maintenance: The previously used heated bright nickel plating solution can be diluted; after adjusting the concentrations of other components, it can be replaced with a bright nickel plating solution at room temperature. Routine maintenance is exactly the same as that for heated bright nickel. Normally, the addition of expansants and acetylenediol is maintained through so-called \"brighteners\" that are prepared in proportion. My factory produces it by expanding butadiene glycol as a secondary ingredient. Generally, for each ampere-hour of power consumption, it is necessary to add a brightener containing butyridine diol. III. Problems that occur during production and their solutions. Symptoms of the problems: poor brightness of the coating, … presence of white fog; sometimes the brightness is even extremely low… Causes of these problems. To solve the problem, add acetylenediol; calculate the exact current required. After adsorption with activated carbon, dissolve the wetting agent and then add it. Insufficient current flow; the amount of coating agent used is too low. There are pits on the surface of the coating layer – the wetting agent has not been dissolved properly. The values are too high; there is a lack of wetting agent, and the current density is too high. Add the wetting agent in the correct manner and strictly adhere to the regulations. The content of acetylenediol in the coating layer is too high; there are excessive organic impurities in the solution. Metals such as iron are present in the electrolyte; the sugar content is too low. The coating layer peels off, especially after chromium plating. The surface of the coated parts is not properly degreased; there are too many impurities in the coating solution. The interruption time during electrolysis is too long. The nickel coating layer is brittle. Avoid excess amounts; if excess occurs, add activators and use activated carbon for adsorption. Carry out chemical treatment or use lower concentrations. Add saccharin to enhance degreasing. Avoid interruptions in power supply. To address the brittleness of the nickel coating layer, adjust the conditions appropriately. There are burrs and pinholes on the surface of the coating layer. IV. Determination of plating solution and coating properties – Measurement of deposition rate: A piece of square-inch brass sheet is taken, polished, and then plated. Conditions, time in seconds and minutes, temperature, pole pitch in millimeters. The thickness is the average thickness in micrometers of the middle part of the copper sheet. Determination of deep plating capability: Unpolished Wanchang copper tubes were etched with nitric acid and then plated. The conditions are parallel and perpendicular to each of the anode plates; the parallel ones are positioned away from the anode, with the rest being the same as before. As a result, a nickel layer was deposited on the inner wall of the copper tube. Take a product clip and open the jaw angles accordingly. Plating. Under the same conditions as before, after the plating process for several minutes, the areas on the sides that are not exposed still need to be illuminated with a lamp in order to allow chromium plating to occur there. Determination of dispersion capacity: Take two brass sheets, with conditions of length in decimeters and time in minutes. Pole pitch. The thickness measurement results are divided into upper joint, middle joint, and lower joint. Polar distance: For measuring thickness, the upper part is examined, the middle part is tapped, and the lower part is used to assess strength and toughness. To determine strength, a brass sheet is taken, polished, then coated for a certain number of minutes; after that, it is folded repeatedly until the sheet breaks, with no signs of coating peeling off. The Xiangguu cervical forceps were first plated with dark nickel for one hour, then coated with bright nickel at room temperature for a certain number of minutes before being taken out; no delamination was observed after bending them and then straightening them again. Toughness: Brass sheets were taken, polished and degreased, immersed in a chromium solution for a few seconds, then coated for a certain number of minutes; the coating was removed afterward. The sheets were folded and then forced to be separated into three parts, with no breaking occurring. Pore measurement is carried out using the method for testing toughness; after plating, the sticker method is employed to verify compliance with the Ministry of Health’s standards regarding pores in nickel-plated layers. After removing the layer, pinholes were observed under the backlight; there were fewer pinholes in the coating of the heated and bright nickel. Analysis shows that due to our factory’s shortcomings in terms of testing equipment and technical capabilities, the measurements of the properties of the plating solution and the coating are undoubtedly rough. However, for our organization, we believe that the process of producing bright nickel at room temperature has practical value for industrial use. V. Conclusion: Normal-temperature bright nickel is a new manufacturing process. Although our factory has started producing using this method and has managed to resolve some of the problems that arise frequently, due to our limited theoretical knowledge and lack of thoroughness in our work, we are not yet able to develop a complete set of solutions. We hope that colleagues will work together in future efforts to improve this new process of normal-temperature bright nickel, so as to make it more efficient and effective in serving socialist construction.