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High silicon die casting aluminum alloy hard anodizing

Release time:

2023-03-23 11:41

01 Why die-cast aluminum alloy?

Different brands and types of products have different requirements for aluminum housings, which are manifested in shape, size and appearance. There are two kinds of processing technology:CNC Machining and Die Casting. Both are technologies for processing raw materials into products. CNC machining refers to precision machining under computer numerical control. The aluminum housing can achieve some extremely special or complex surface treatments under this processing technology. It belongs to the high cost in exchange for high quality, such as the Apple series.

The die casting process uses a mold cavity to apply high pressure to the molten metal to form a surface effect similar to the mold. Some simple stamping and pattern work can be done under the die casting process. Compared with CNC machining, the cost of die casting is lower and the processing time is short, but extremely complicated surface treatment cannot be performed.

 

02 Introduction of Die Casting Aluminum Alloy

Die-cast aluminum alloys generally containhigher silicon contentThe anodic oxide film is dark, and it is impossible to obtain a colorless and transparent oxide film. With the increase of silicon content, the color of the anodic oxide film changes from light gray to dark gray to black gray. Commonly used die casting aluminum alloy, can be divided into three categories:

① Al-Si alloy, mainly including YL102(ADC1, A413.0, etc.), YL104(ADC3, A360);

Aluminum-silicon copper alloy, mainly including YL112(A380, ADC10), YL113(A383, ADC12), YL117(B390, ADC14);

Aluminum magnesium alloy, mainly contains 302(5180, ADC5, ADC6).

 

03 Anodizing of high-silicon die-casting aluminum alloys

high silicon aluminum alloyIt has large latent heat of solidification, specific heat capacity, small linear shrinkage coefficient and good plasticity, and is widely used in the manufacture of die castings. The die-cast aluminum alloy parts have high strength, corrosion resistance and processing performance, and have the characteristics of energy saving and raw material saving.Therefore, die-casting aluminum alloy is widely used in aviation industry, shipbuilding industry, automobile manufacturing industry, home appliance hardware, instrumentation and other industries.The silicon content in die casting aluminum alloy is high, and there are many phases in the structure, which is easy to cause the crystal orientation segregation of silicon. If it is not processed in time, it will form a galvanic cell with the water vapor in the air, which will cause very serious electrochemical corrosion and even cause the parts to be scrapped. In recent years, the useanodic oxidation methodTo improve the corrosion resistance of cast aluminum alloys, mainlyhard anodic oxidation process. Because the aluminum alloy after hard anodic oxidation treatment, will generate a layer on its surfaceOxide film up to tens of microns or more, This oxide film has extremely high hardness, good wear resistance and insulation.

The surface treatment of aluminum alloy is mainlyImprove the corrosion resistance, wear resistance and hardness of the aluminum alloy surface, and extend the service life. Can also be anodized after the surface of the aluminum alloyColoring treatment, applied to decorative materials.