Что такое литье под давлением? Все, что нужно знать о литье металлов
литьё под давлениемThis is a manufacturing process in which molten metal is forced using pressure to fill a mold cavity also known as die casting. The mold is usually of high-quality steel and hence the part can be produced in large quantities the term is used to mean the manufacture of many parts. The finished part is then produced by opening the mold after the molten metal is cooled and forms a solid layer. This kind of use of the process is mostly applied in making intricate metal used in the production of different parts that require high accuracy in measurement and polished surfaces. Die casting can be done on aluminium, zinc, and magnesium but other metals can also be used on a case depending on application and other requirements. Die casting is considered to be one of the expert manufacturing techniques in the conception of mass production of small to medium-sized components out of metals. The popularity of the method has been spread across automotive, aerospace, electronics, and industrial machines due to its ability to produce durable lightweight intricately tailored parts. However, this process is widely recognized for its ability to manufacture products with complex geometry that would be very hard to make using conventional techniques. How Die Casting Works Molding is the first part of the die-casting process. On one side of the mold, there is a half, and it is a half of a particular design to make the mold shaped like the final product. Cavities and cores are designed for the molds that are usually custom-made so that the part can be replicated as closely as possible. 1. Molten Metal Injection: Then the molten metal is injected into the mold cavity under high pressure to form the desired shape. The metal is usually heated to one degree above the melting strain to make it fluid. In die casting, the pressure that the molten metal is pushed into the mold can be from several thousand to tens of thousands of psi (pounds per square inch), to be sure that the molten metal gets into every detail of the mold. 2. Solidification: This occurs when the metal is injected into the casing cavity whereby it cools and the metal hardens. The quality of the casting depends upon the cooling rate. Additional modes of failure (shear, climb, and glide) come into play in this case and result in faster cooling higher strength better surface finish, and slower cooling which could result in more internal defects and lower mechanical properties. Water-cooling systems built into the mold are usually used to assist the cooling process. 3. Ejection: Following this, the metal is allowed to cool and solidify and it is then easy to remove the mold from the larger casting and eject the part. Then most of the time is used in the pushing out part from the mold using a mechanical ejector system. This depends on the complexity of the part that requires other extra steps, namely trimming and machining to deliver the final shape and dimension. 4. Quality Control: A quality check is then performed on a part after ejection. It can involve dimensional verification, visual inspection, and mechanical testing to confirm that the part is equal to or better than the requirements. High precision and repeatability are theoretically achieved in die casting. Types of Die Casting There are two types of Die casting, they are hot chamber die casting and cold chamber die casting. These are all good and have their advantages, limitations and ideal applications. 1. Hot Chamber Die Casting The process most suitable for metals such as zinc, magnesium, and lead is a hot chamber die casting since the process is done at high temperatures, and melting points. The injection system is installed inside the melting furnace in this way, the metal is always in contact with the chamber. Advantages: Disadvantages: 2. Cold Chamber Die Casting The metals that have higher melting points like aluminium, brass and copper are cast in cold chamber die casting. In this case, the molten metal is tapped from a second furnace injected into the cold chamber then into the mold cavity. Advantages: Disadvantages: The Comparison of Die Casting Methods: Hot Chamber vs. Cold Chamber Here is a comparison of the most common types of two die-casting methods, Feature Hot Chamber Die Casting Cold Chamber Die Casting Metal Compatibility Best for low-melting-point metals (e.g., zinc, lead) Best for high-melting-point metals (e.g., aluminium, brass) Cycle Time Faster cycle times Slower cycle times Mold Wear Higher mold wear due to direct contact with molten metal Lower mold wear Cost Lower cost for high-volume production Higher initial cost, but better for high-strength metals Complexity of Parts Good for simpler parts Better for more complex, larger parts Advantages of Die Casting It is one of the largest advantages that die casting is one of the main preferred methods of large-scale production of products from metal alloys. 1. High Precision and Accuracy There are many advantages of die casting, which makes it convenient to offer high die precision. This method of production is also widely used for the production of parts, which requires good dimensional accuracy which is very crucial as it defines tolerance levels required in a specific job. One should note that die casting is the only manufacturing technique that can produce given parts with the utmost complexities such as the intricacies of its geometries. 2. High Production Rates In terms of large volumes, die casting is very efficient. Parts are quickly and cheaply produced once the first mold is created with very little labor involved. The demand for simulated powders is particularly high in industries like automotive and electronics where large volumes of the same parts are required. 3. Complex Designs and Thin Walls Complex design can be achieved by die casting, which would be difficult or impossible to achieve by traditional manufacturing methods. The process can make parts with thin walls, and complex internal structures, and can accommodate undercuts; thus making it the
