Views: 220 Author: yuechen-edit Publish Time: 2019-06-13 Origin: Site
Injection molding is a manufacturing process in which molten metal is poured or pressed into steel molds. Molds, also called tools or dies, are created using steel and are specially designed for each project. This way, it is possible to create each component with repeatability and greater precision. Magnesium, zinc and aluminum are the most commonly used injected alloys.
Injected castiron can have significant advantages in other manufacturing processes, which often entail significant cost savings, not only in terms of the price itself, but also in the total cost of production. When a piece fused, complex definitive forms can be created, including external threads and internal complex geometries with minimum wash angles (reducing secondary operations). Multiple pieces can also be combined into one, eliminating assembly operations and reducing labor costs, with the added benefits of simplified stock control and greater component consistency.
Separately, each cast alloy offers a variety of benefits that the other may not offer. That is one of the biggest advantages of injected casting, there are no limits when choosing the right metal.
Aluminum, Zinc, and magnesium are the three main alloys used in die casting. Normally, they are non-ferrous metals and there is a great variation in their mechanical properties which enables them to fit almost any application needs of a manufacturer. Cast iron alloys not only withstand high operating temperatures, but are also fully recyclable.
Cast iron alloys also have:
· Good corrosion resistance
· High thermal conductivity
· High strength and hardness
· High electrical conductivity
· Good finishing characteristics
· Exceptional EMI or RFI protection properties
In the aluminum die casting technique, the mold is not destroyed in each injection, it is permanent, and it is made of a steel metal for hot work. There is a series of foundry processes, the high-pressure casting is the most used, representing around 50% of all light alloy casting production. Low pressure casting currently accounts for around 20% of production and its use is for parts with demanding mechanical characteristics.
In aluminum die castings process, the liquid metal is injected at high speed and pressure into a metal mold.
This equipment consists of two vertical plates in which are placed mold holders that hold the halves of the matrix. One fixed plate and the other has movement for the demolding of the piece. A dosed amount of molten aluminum is poured into the container and then introduced into the mold cavity using a hydraulically actuated piston. Once the metal has solidified, the mold opens and the injected part is removed.
In the aluminum die casting process, special precautions must be taken to avoid inclusions of gases that cause blistering during the heat treatment or welding of the casting product.
Conventional casting molds are designed with individual or multiple cavities. The mold is designed to be efficient and reducse secondary operations helping to reduce costs. Other benefits of conventional casting molds include:
· Finished piece of cast iron, with a focused design to avoid secondary operations
· Molds that are designed to efficiently manage a high volume of production
· Efficient production with cooling and properly planned water circuits
· Reinforced steel dies that favor the life of the tool