After various anodizing treatments on aluminum products, the quality and performance of the oxide film on the surface of the product shall be subjected to the necessary quality inspection according to the technical conditions. There are several main items for the inspection work.
1 Determination of thickness
Under the same conditions, the corrosion performance and wear resistance of the oxide film are directly proportional to its thickness. Therefore, oxide film thickness is an important technical parameter, and oxide film thickness measurement is divided into destructive test and non-destructive test.
2 Detection of corrosion resistance
The wear resistance of aluminum and aluminum alloy anodized films is related to alloy composition, electrolysis conditions, film thickness and sealing treatment conditions. In addition, it is related to the actual use environment. Experiments for testing corrosion resistance include drop alkali test and aversion test.
3 closed effect test
There are mainly dyeing methods, phosphochromic acid methods, and admittance methods. The dyeing method first degreases and treats the oxidized sample, then stains with the dyeing agent, and observes the dyeing condition during the observation period. According to the loss degree of the adsorption capacity of the oxide film, the anodic oxide film is subjected to the long-term absorbing dyeing adsorption capacity. In one case, the strong anti-staining adsorption capacity indicates that the sealing quality is excellent.
The unencapsulated anodized film will be quickly dissolved in a specific acidic medium, and the two well-sealed cultivar will undergo long-term intrusion without significant erosion. Based on this principle, the chromic acid is said to be infiltrated into the phosphochromic acid solution, and the quality of the closure is evaluated according to the quality loss.
The admittance method is indirectly judging the closed mass from the electrical insulation of the anodized film. The anodized film of aluminum and its alloys can be equivalent to a circuit composed of a series of resistors and capacitors in series and in parallel in an alternating current circuit. The admittance method is used to determine the surface admittance value of the anodized film of aluminum and aluminum alloy after sealing, and the electrical insulation of the oxide film is known.
4 wear resistance test
The wear resistance of the anodized film can reflect the friction and wear resistance of the oxide film, which is closely related to the quality and use of the film. The wear resistance test mainly depends on the metal composition, the thickness of the film, the anodizing conditions and the sealing conditions. The abrasion resistance test has a blast abrasion test, a doffing wear test, and a wheel wear test.
5 hardness test
The hardness test of the anodized film is divided into a Hua Heng method and a press-in method.
The scratch method includes pencil scratch method, pressurized steel ball method, and 侳 type hardness test method. The pencil scratch test method is the simplest. Use 6B~9H pencil to make it 45 degrees Celsius with the test piece. Next, I want to draw 10mm in front and draw 4 times. If there are no scratches 2 or more times, the hardness of the pencil used is the hardness value of the oxide film.
6 other tests
It has anti-fracture performance test, reflection characteristic test, continuity test, and light fastness test.