Die-casting technology is a common molding process for radiators, which occupies a place in various molding processes of radiators. Especially for some parts of the radiator that dissipate heat through the shell, as well as the heat dissipation of LED lamps.

Today, I will share with you the common materials and production issues of die-casting technology.

When mechanical engineers choose die-casting materials, they should choose the correct die-casting materials according to various factors such as the performance of the product, process performance, production conditions, economy, and the characteristics of the die-casting materials. Common die-casting materials for mechanical parts include aluminum alloys, zinc alloys, and magnesium alloys.

Aluminum alloy is the most widely used die-casting material at present, and it is widely used in the automotive industry, motorcycle industry, aerospace, etc. The characteristics of aluminum alloy are as follows:

(1) The density of aluminum alloy is small, only about 1/3 of iron, copper, and zinc. Its high specific strength and specific stiffness are its outstanding advantages.

(2) Aluminum alloy has good electrical and thermal conductivity.

(3) Aluminum alloy has good anti-oxidation and corrosion resistance. In the air, the surface of aluminum is easy to form a dense trioxide disulfide oxide film, which can prevent further oxidation.

(4) Aluminum alloy has good die-casting performance. The die-casting process of aluminum alloy is simple, and the forming and cutting performance is good. It has high mechanical properties and corrosion resistance and is the most potential alloy to replace steel castings.

(5) Aluminum alloy has good high-temperature mechanical properties and maintains good mechanical properties when working at low temperatures.

(6) The disadvantage of aluminum alloy is that it is easy to produce large concentrated shrinkage holes at the final solidification position. In addition, aluminum alloy has a strong affinity with iron and is easy to stick to the mold. It should be pressed on a cold chamber die-casting machine.

Zinc alloy is also relatively common, and the characteristics of zinc alloy are as follows:

(1) Zinc alloy has excellent casting performance, mechanical properties, and toughness, and is widely used in traditional mechanical parts, hardware, locks, toys and other industries.

(2) Zinc alloy has excellent electrical and thermal conductivity, good vibration damping characteristics, and good electromagnetic shielding performance. Its application in electronics, telecommunications, and home appliances is growing.

(3) Zinc alloy is a universal, reliable, and low-cost material that is easy to die-cast. Zinc alloy has good die-casting performance, so it is easier to die-cast products with complex shapes, thin walls, and high dimensional accuracy. Due to the thin-wall casting performance of zinc alloy, it can achieve the requirements of product lightweight and cost reduction.

(4) Compared with aluminum alloy and magnesium alloy, zinc alloy has higher tensile strength, yield strength, impact toughness, and hardness, and better elongation.

(5) The surface of zinc alloy die-casting parts is very smooth and can be used directly without surface treatment. At the same time, it is relatively easy to perform various surface treatments such as polishing, electroplating, and spraying to obtain better surface quality.

(6) Zinc alloy has a low melting point and melts at 385℃. Compared with aluminum alloy and magnesium alloy, zinc alloy is the easiest to die-cast.

(7) Poor corrosion resistance. When the impurity elements lead, cadmium, and tin in the zinc alloy composition exceed the standard, they will gradually age and deform, manifested as volume expansion, and significant decrease in mechanical properties (especially plasticity). After a long time, it will break.

(8) Aging. If the use time is too long, the shape and size of the zinc alloy die-casting will change slightly.

(9) Zinc alloy is not suitable for use in high-temperature and low-temperature working environments. Zinc alloy has good mechanical properties at room temperature, but its tensile strength decreases significantly at high temperatures and its impact resistance decreases significantly at low temperatures. Zinc alloy is easy to age, which is the main reason why the application range of zinc alloy is limited. The working temperature range of zinc alloy is narrow. When the temperature is lower than 10℃, its impact toughness drops sharply. When the temperature rises, the mechanical properties decrease, and creep is prone to occur. Therefore, the temperature of the stressed parts generally does not exceed lOOC. Strictly control the purity of zinc alloy raw materials and the smelting process. Adding a small amount of Mg and an appropriate amount of Cu to zinc alloy can reduce or eliminate aging phenomena and improve cutting performance.