Pretreatment method of chemical nickel-phosphorus plating of aluminum and aluminum alloy and application

Abstract

The invention belongs to the field of chemical technology and metal material surface protection treatment methods, and relates to a pretreatment method of chemical nickel-phosphorus plating of aluminum and aluminum alloy and application of the pretreatment method in the field of metal material surface protection treatment. The method comprises the steps of: organic solvent oil removal, stress relief annealing treatment, chemical oil removal, electrolytic passivation treatment and activating treatment. A production test proves that an aluminum and aluminum alloy surface passivation film layer prepared by the pretreatment method is very uniform, the binding force of a plating layer is obviously increased, and the plating layer has certain porosity, so that a good metal surface condition is provided for a later chemical nickel-phosphorus plating process, and the occurrence rate of product quality problems such as nickel-phosphorus layer falling and bubbling can be greatly reduced; and the pretreatment method is simple in technological process, stable in product quality and low in production cost, and obviously reduces pollution compared with that of a traditional zinc immersion process.

Description

technical field [0001] The invention belongs to the fields of chemical technology and metal material surface protection treatment methods, and in particular relates to a pretreatment method for aluminum and aluminum alloy electroless nickel-phosphorous plating and its application in the field of metal material surface protection treatment. Background technique [0002] Aluminum and aluminum alloys are the most widely used metal materials among non-ferrous metals. They have a series of excellent physical, chemical, mechanical and processing properties and characteristics, such as low density, high plasticity, easy strengthening, good conductivity, and durability. Corrosive, easy to recycle, weldable, easy to surface treatment, etc., after various surface treatment technologies, it has been widely used in industries such as aviation, aerospace, ships, automobiles, motorcycles, electronics, instruments, textile machinery and household appliances. application. [0003] However,...

AI Technical Summary

Problems solved by technology

Although this method is effective and widely used, there are still some defects. On the one hand, the operation is cumbersome and the technological process is complicated. An alkaline nickel immersion process is added after the first zinc immersion; on the other hand, the process standardization is not good, the product quality is unstable, and the processing cost is high. If the quality is not high, it will directly affect the bonding force of the coating and the stability of the bath, resulting in the peeling off of the coating of the product, and even the serious consequences of disintegrating and scrapping the bath.

[0005] In summary, in order to overcome the defects of the traditional galvanizing process, such as cumbersome process, high processing cost, unstable product quality, and high pollution, the pretreatment process of electroless nickel-phosphorus plating on aluminum and aluminum alloys needs to be further improved.