Casting is a simple and inexpensive way to shape Aluminum into a wide range of products. Items like car engines and power transmissions can be made with the Aluminum casting process.
Most of the large Aluminum castings make use of sand molds. Much technical advancement has been made in casting Aluminum, but the basic principle remains the same: pouring molten Aluminum to a mold to make a desired pattern.
The three main methods used in Aluminum casting are die-casting, sand casting, and permanent mold casting. Let us look into the details of these three methods to cast Aluminum.
Die Casting
In the die casting process, molten Aluminum is forced into a steel die under high pressure. Die casting technique is used is used in production of high volume Aluminum products.
This method can be used to precisely make Aluminum parts that require minimum machining and finishing. In addition, the method is suitable to make lighter parts that need more surface finishing.
Aluminum die casting is versatile, has high dimensional stability with thinner walls and is corrosion resistant. This method can be used in almost any metal manufacturing industry.
Permanent Mold Casting
This technique involves using cores and molds that are made from steel or other metal. In this technique, molten Aluminum is poured into the metal mold and sometimes vacuum is also used for molding.
The advantage of this method is that the castings made by permanent sand casting are stronger than that made by sand casting or die casting. When it is impossible to remove the permanent cores, semi permanent mold casting is used.
Sand Casting
This is the most versatile technique that is used for casting Aluminum into different products. This process uses a pattern that is a replica of the finished product. Theoretically, any pattern can be pressed into a sand mixture to make the mold into which the molten Aluminum is poured to make the finished product.
In this molding technique, the pattern will be slightly larger than the part to be made. This is to allow for the shrinkage of the metal during cooling and solidification of the metal.
When compared to the other two techniques, this method is slow but more economical to make products in small batches. Besides that, the method is best to make intricate product designs and for large castings.