Porosity detection of nickel plated parts is a key link in evaluating the quality of coating. The level of porosity directly affects the corrosion resistance, hardness and aesthetics of the coating. Therefore, it is crucial to choose an appropriate detection method.
Common methods for detecting the porosity of nickel plating include corrosion method, electrical imaging method, gas permeation method and photography method. Among them, the corrosion method uses specific chemical reagents to display the pores of the coating, and then counts the pore spots to evaluate the porosity; the electrical imaging method uses electrochemical principles to directly observe and measure the pores through image analysis technology; the gas permeation method indirectly evaluates the porosity by measuring the rate at which gas passes through the coating; the photography method captures the tiny pores on the surface of the coating through high-resolution photography.
The corrosion method is easy to operate and has low cost, but it may cause certain damage to the coating, and the detection results are greatly affected by human factors. The electrical imaging method has a fast detection speed and accurate results. It is suitable for porosity detection of large-area coatings, but the equipment cost is high. The gas permeation method is suitable for the detection of thin coatings or tiny pores, but the operation is complicated and affected by conditions such as temperature and pressure. The photographic method can provide detailed images of the coating surface, but the detection efficiency is relatively low.
The porosity of the nickel-plated layer is affected by many factors, including coating thickness, bath composition, electroplating conditions, substrate quality, etc. As the coating thickness increases, the porosity usually decreases; the types and contents of impurities and additives in the bath affect the crystallization quality and porosity of the coating; electroplating conditions such as current density, temperature, stirring intensity, etc. also affect the deposition rate and porosity of the coating; the roughness and cleanliness of the substrate surface directly affect the bonding force and porosity between the coating and the substrate.
In addition, bath maintenance is also an important factor affecting the porosity of the nickel-plated layer. Impurities such as suspended matter and precipitate in the bath should be removed in time to keep the bath clean and stable. At the same time, parameters such as pH value and temperature of the bath should also be strictly controlled to ensure the stability of the coating quality.
In practical applications, appropriate porosity detection methods and control measures should be selected according to the specific requirements and conditions of nickel plated parts. For example, for aerospace parts with higher requirements, more accurate electrical imaging or photography should be used for detection, and the composition of the plating solution and the electroplating conditions should be strictly controlled to reduce the porosity.
The porosity detection method and influencing factors of nickel plated parts involve many aspects, and it is necessary to comprehensively consider factors such as coating quality, detection efficiency and cost for selection and optimization. Through scientific detection methods and effective control measures, the quality and performance of nickel plated parts can be significantly improved.
