Die-casting aluminium alloy

Abstract

A aluminium alloy for press casting very thin parts (0.7-1.2 mm) is composed of (by weight) 10.0-14.0 % of silicon, 2.5-4.5 % of copper, 0-2.0 % of nickel, 0-1.5 % of manganese, the total content of nickel and manganese keeps in 0.5-2.0 %. The alloy castability (mold filling ability) increases by more than 20 %. Under high pressure press casting, 0.7-1.2 mm wall casting can be made and can be used as casing of 3C products, also the cost is reduced by more than 20-30 % compared with magnesium alloy.

Description

technical field [0001] The present invention relates to aluminum alloy for die-casting, in particular to an aluminum alloy for die-casting extremely thin parts. Background technique [0002] In recent years, the 3C industry has developed rapidly. Among them, the casings of notebook computers, digital cameras, and communication mobile phones all require the characteristics of lightness, thinness, and anti-electromagnetic radiation. For this reason, magnesium alloys and aluminum alloys are widely used to make molded parts through high-pressure die-casting. . In the past two years, the trend has been to move towards magnesium alloys, because castings of the same thickness are about 30% lighter than aluminum alloys. Another factor is that the fluidity of aluminum alloy components in various countries in the world is relatively limited. Even under high-pressure die-casting, it is difficult to achieve a thickness of less than 1mm, which cannot meet the requirements of some casing...

AI Technical Summary

Problems solved by technology

[0004] 1. The raw material price of magnesium alloy is slightly more expensive per kilogram than that of aluminum alloy

[0005] 2. The first-class waste of magnesium alloy castings (about 1.5-2 times the weight of the finished product) is difficult to recycle and remelt in the factory due to the increase in the content of impurities (such as iron, nickel, copper, silicon) and oxides. Therefore, the weight ratio of the magnesium alloy used from the feed to the finished product is extremely low, about 35% to 40%, resulting in a huge waste of resources and energy

[0007] 4. Subsequent treatment of magnesium alloy castings is more than 50% more expensive than that of aluminum alloys, mainly because magnesium alloys need to be treated with a film and surface defects often require a rather manual filling process

[0008] Based on the above factors, it is necessary to use a large amount of aluminum alloy to reduce the cost of 3C casing die-casting castings. However, as mentioned above, the fluidity of aluminum alloys in all countries in the world is relatively limited, and it is difficult to achieve thin parts below 1mm.