Injection molding of metals , zamac, aluminium
Casting metal is often used in making everyday products such as cars, cell phones, kitchen utensils and metal sculptures. The casting of metals knows several methods, but has the same principle. For this process, molten metal is required to be poured into a mold. The mold has a hollow cavity in the shape of the part to be produced. When the mold has been filled, it can be cooled until the molten metal solidifies. The part which is formed in the mold, is also known as a casting.This process is often used by the great freedom of form. A product can then usually be made in one step, whilst the same product with a different manufacturing process would have to consist of several components, and then would have to be assembled to each other. The freedom of form and high strength in the products are the most important benefits in the casting of metals. However, these advantages come at a price. Especially with large batch sizes in which a high production rate is necessary, the cost become higher, but also by high-quality requirements, such as: narrow tolerances, a uniform character and an (almost) perfectly finished surface in the part. Metals that can be used for casting are: aluminum, bronze, cast iron, cast steel, gold, lead, magnesium, titanium, tin, zinc alloy, silver and zinc. The choice of the material is made among others based on the moldability, specific heat and solidification temperature. you can also check this webiste : find a chinese mold maker
The casting process
First of all, the molten metal poured into the mold. This can be done, in principle, in contrast to synthetic materials, to every speed and pressure. However, it may be too fast flowing of the material (or turbulent flow) to ensure that the material does not fill the entire mold, but here and there leave air bubbles. When the metal then solidifies, these air bubbles may be visible on the surface. In order to prevent this, there are different types of molds made for the maximum flow rates. On the other hand the material that is cast by injection mold company and can start to solidify slowly pouring thus ensure parts which solidify more quickly than other parts. For a good quality, it is important that all of the material must solidify homogeneous. A solution for this is the filling of the mold through a plurality of openings so that the material remains below the maximum flow rate, but can still be filled quickly enough. When additional pressure is supplied during the filling of the mold, the sharp radii will, narrow parts and small details will be better formed in the cast component. The dies can be made of sand, metal, or anything else so long as it does not melt along with the molten metal or deformed
Cooling and solidification
Upon solidification, the material is not only faster, but the volume also becomes less; there occurs shrinkage. After the material has solidified, it can be further cooled to room temperature, wherein there is more shrinkage will occur. The degree of shrinkage depends on the thermal properties of the type of metal. These properties are also decisive for the temperature necessary for melting of the metal. The main feature here is the specific heat which represents the amount of heat energy to produce one kilogram of material by one degree temperature rise. In addition, the material has a solidification temperature which is used to solidify the liquid material. Finally, the material will cool to room temperature. There does not need to be waited until the material cools to room temperature; the part can be already removed from the mold when it is solidified and further cooling outside the mold.The mold may then be re-filled with molten metal. In this way, the production cycle will be faster.
There are a number of methods for casting metals. Each method has it's advantages and disadvantages. The right choice for the treatment shall be made on the basis of the structure of the specific, cost and quality. The methods have the same principle, but differ in the manner in which the mold is filled and the material of the tooling mold itself. Listed below are the most well-known casting methods have been described. Sand Casting