A customer inquired that during the production process of using high phosphorus chemical nickel plating solution, they would require the workpiece to undergo a nitric acid resistance test to determine the corrosion resistance of the chemical nickel plating layer. However, most of the workpieces failed the test. What is the reason for this?
Based on the field experience and the characteristics of the product high phosphorus electroless nickel plating solution Ni-811, Bigley Technology has analyzed that the chemical nickel workpiece immersed in nitric acid will gradually produce a large number of bubbles, and the coating surface will gradually darken. Generally, the workpiece shall be qualified if the time from immersion in nitric acid to darkening is more than 20 seconds. There are two main reasons for the unqualified nitric acid resistance test of the workpiece:
1. The chemical nickel plating solution is operated improperly or has a later lifespan. Generally, the stability of the plating solution for newly opened cylinders is good, and the corrosion resistance of the plating solution is also good. The workpiece coating can pass the nitric acid resistance test. But if the stability of the plating solution is poor due to improper operation, or if the plating solution is in the later stage of its lifespan, the workpiece will fail the nitric acid resistance test.
2. The performance of high phosphorus electroless nickel plating solution is poor. Some chemical nickel plating solutions on the market have poor stability due to technical formulas, resulting in rough and loose coating crystallization, and unstable nickel content in the coating. As a result, the corrosion resistance of the workpiece coating is poor, and it naturally cannot pass the nitric acid resistance test.
Therefore, we should choose high phosphorus electroless nickel plating bath with good performance in the production process, such as the Ni-811 made by Bigley, and strictly control the bath to have good chemical stability, so as to ensure that the workpiece can pass the nitric acid test. If you are interested in high phosphorus electroless nickel plating solution, please contact Bigley customer service to obtain free samples and detailed technical information!
If you want to learn more about electroless nickel plating, you can click to view the "Electroplating Encyclopedia".