In recent years, zinc alloy die casting techniques develop rapidly. The economic benefits and market benefits resulting from this cannot be underestimated. According to experts, zinc alloy die casting techniques have the following features:
1. Relatively large proportion in casting techniques.
2. Excellent castability, thus easily forming thin-wall precision casting parts with complex shapes and smooth surfaces after die casting treatment.
3. Allowable for surface treatment, such as electroplating, spray coating, paint spraying, polishing, grinding, etc.
4. Free of attracting iron, corroding casting forms and sticking molds in the melting and die casting process.
5. Good mechanical properties and abrasion resistance at room temperature.
6. Low melting point, contributing to easy die-cast formation.
Zinc alloys are crucial to zinc alloy die castings. It is necessary to understand some features of zinc alloys before understanding zinc alloy die castings. Zinc alloys have the following main features. Firstly, the melting point of zinc alloys is relatively low. At the temperature of 400 °C, zinc alloys begin to melt, which contributes to the relatively easy forming of zinc alloy die castings. Secondly, zinc alloys are free of attracting irons in the melting and die casting process, and have excellent castability. Thus, precision casting parts with complex shapes and very smooth surfaces are easily formed after the die casting process. In the meantime, the proportion of zinc alloys in such parts is relatively large.
Zinc alloy die casting techniques with the focus of improving casting quality are widely applied in the injection molding process. For those who have good knowledge of zinc alloy die castings, it is easily understood that runners and excess materials are parts of die castings, and, although they are useless, the expense of them is also included into the costs of die castings. Meanwhile, remaining zinc alloys are recyclable and are usually sent back to the original supplier in exchange for new materials. But if remaining zinc alloys are not well dealt with, they will pollute air and harm environment. There are various kinds of recycling methods for remaining zinc alloys, partially because zinc alloy die castings contain some other alloying elements like aluminum and copper, apart from mainly containing zinc. The manufacturing process of zinc alloy die castings are divided into two methods, namely casting of zinc alloys and deformation of zinc alloys, both of which have their own characteristics in the die casting process.