Casting of Magnesium Alloy Parts
Brass and zinc constitute two of the most common alloys used in die casting, but magnesium may be gaining popularity in the manufacturing industry due to its unique properties. Magnesium alloys offer excellent strength and light weight, making them perfect for parts that need to be as strong and lightweight as possible.
Magnesium is also non-toxic and, when properly alloyed, extremely corrosion-resistant. It is one of the most prevalent castable materials, and its fabrication uses have increased significantly in recent years.
Due to these properties, and the relatively low cost, magnesium casting is an attractive option for many automotive and aviation parts. Commonly used for suspension components, camshafts, wheels, and much more, magnesium alloy parts are especially desirable for high-performance automotive parts.
However, because magnesium is a reactive metal, it can be difficult to cast. For example, there is the risk of porosity in magnesium alloy parts due to the high segregation of elements in the melt. If the magnesium is not properly alloyed to the proper levels of alloying elements, porosity and hot tears can occur, resulting in a casting that is unsuitable for use.
The production process of magnesium alloy parts includes preparation of the die cavity, molten magnesium injection into the die cavity, cooling of the metal and removal of the casting. For a successful metal casting, the metal has to be poured into the die at a temperature that is optimal for metal flow but low enough to form a solid casting. The combination of pressure and heat maintain the metal in a semi-liquid state, allowing it to fill the entire die cavity.
Casting also helps eliminate machining and finishing, reduces scrap, and speeds up production time. It can also produce precision-machined parts to very tight tolerances. For example, when creating complex parts, the intricate shapes can be produced without costly and time-consuming machining.
It is essential to follow strict control procedures during the production process to ensure that the cast parts remain free from defects and have the desired strength and dimensional characteristics. This includes frequent testing of part samples to ensure they meet the specified requirements.
Unlike other metals, magnesium alloys present unique challenges during the casting process, but when properly alloyed, these challenges can be easily overcome. Magnesium alloy parts can offer designers and manufacturers a unique blend of strength and weight that may not be available through more traditional options. Through effective quality control procedures, cast magnesium alloy parts can be produced to meet the desired specifications.
