Views: 242 Author: Site Editor Publish Time: 2019-08-08 Origin: Site
When you talk about general casting, you refer to a rather simple, relatively cheap and versatile method of forming aluminum into a wide range of products. These products range from the very simple items used in the homes and offices to relatively large and heavy ones like the cap atop the Washington monuments, car engines and the power transmission components all produced through the process of aluminum die casting.
There is one special thing about most castings which is the fact that they are usually made in sand molds. This is the case with those large aluminum products.
Aluminum undergoes cold-chamber die casting due to its high melting point. During this process, the metal is melted in an oven at extremely high temperatures and then dosed in a cold chamber to be injected into the mold.
When choosing a more satisfactory aluminum die casting products, it is important to pay attention to some important factors.
Aluminum casting products fall into various categories thus;
In casting with sand mold, patterns are very important as they are used to create the molds. Here, the preparation and joining of these sand molds is a very important step.
Patterns or molds are needed to create the empty cavity inside the sand and in this way make the desired part
• The dry sand method which consists primarily of sand and synthetic binders that are chemically or thermally cured and
• The "green sand" which primarily consists of sand and clay mixtures
Sand casting consists of emptying molten aluminum in the mold with the shape of the piece or object to be manufactured and waiting for it to harden on cooling. Other most common cast metals that can be used include cast iron, steel, aluminum alloys and brass.
Sand casting is based on the principle of gravity i.e. the only source of energy that forces the metal to fill the mold cavity is the force of gravity. This type of casting is used for pieces in which the quality of finished and dimensional is not decisive.
The disadvantages are low dimensional accuracy, poor surface finish and low resistance as a result of slow cooling.
Apart from sand casting, aluminum can also be cast using the pressure injection method.
Characteristics of aluminum pressure die casting
- Great accuracy of measures.
- Clean and smooth surfaces.
- Foundry of parts with holes with high precision.
- Production rapidity.
Generally, aluminum pressure die casting is characterized by its cleanliness, accuracy of measurements, dimensional stability, good resistance properties, and better mechanical properties than those cast in sand mold.
In the Gravity die casting products, the production process involves filling the molten aluminum by way of gravity into the metal mold cavity. The gravity filling method helps to achieve less air entrainment or the formation of pores when compare to the conventional aluminum die casting method. With the technique, the final products can be welded and under heat treatment with relative ease.