Aluminum alloy surface cleaning methods
Release time:
2022-03-31
Source:
Aluminum alloy degreasing is an important process in the surface treatment of aluminum alloy components. If the aluminum alloy surface is not cleaned properly, subsequent processing work will be difficult. The contaminants that need to be removed from the surface of the parts include: various oils, residual polishing paste, fingerprints, oil seals, surface wax, etc., that contaminate aluminum alloy parts during processes such as stamping, turning, and milling. Degreasing methods can be divided into solvent degreasing, chemical degreasing, electrochemical degreasing, etc.
1. Solvent Degreasing
Organic solvents have a strong dissolving effect on both saponifiable and non-saponifiable oils, and can remove marking symbols, residual polishing paste, etc., from the surface of the workpiece. The main target is non-saponifiable oil contaminants.
Methods of organic solvent degreasing include scrubbing, immersion, spraying, ultrasonic cleaning, etc. Among them, ultrasonic cleaning is characterized by high efficiency and good oil stain removal effect, especially effective for complex shapes, porous, blind holes, and workpieces with high degreasing requirements. It is currently a commonly used organic solvent cleaning method.
Characteristics: Fast degreasing speed, generally does not corrode metals, but is not very thorough for heavy oil stains, and further cleaning treatment is required through chemical or electrolytic methods.
2. Chemical Degreasing
Chemical degreasing is used to remove invisible oil stains, surface dust, trace rust layers, and some small contaminants formed during transportation or production. Chemical degreasing includes alkaline chemical degreasing and acidic chemical degreasing.
1. Alkaline Chemical Degreasing
Alkaline degreasing is one of the most commonly used methods. Its degreasing principle is to use alkaline solution for the saponification of saponifiable oil stains and the emulsification of non-saponifiable oil stains by surfactants to achieve the purpose of removing these two types of oil stains.
2. Acidic Chemical Degreasing
Acidic degreasing treatment is also a widely adopted degreasing method. Acidic degreasing agents are generally composed of inorganic acids or organic acids, surfactants, corrosion inhibitors, and penetrants.
Characteristics: No heating is required, and good degreasing effects can be achieved at room temperature. If heated to around 40°C, the degreasing effect can be significantly improved; for room temperature degreasing, hard PVC can be used for the working cylinder, while PP should be used for heated degreasing.
3. Electrolytic Degreasing
Aluminum alloy degreasing treatment rarely uses alkaline electrolytic degreasing because this type of cleaning treatment has a significant corrosive effect on the surface of the components, and the equipment investment is also relatively large.
Characteristics: Has a strong reactivity and purifying effect. Electrolytic degreasing is divided into cathodic degreasing and anodic degreasing. Most use cathodic degreasing.
Latest information