If you are new to the die casting industry, gravity die casting may seem highly technical and complex, but in reality, it is quite simple. It may be helpful to think of it as a conversion method or a way of turning one thing into another, converting molten liquid metal (such as aluminum or zinc) into a metal casting or component. This conversion is permanent and can be broken down into a few easy-to-understand steps.
In the following blog, we will detail each of these steps, explain exactly how the die casting process works, and outline what types of products it can be used to make.
Steps of the Die Casting Process
Step 1: Preparation
Before the gravity casting process begins, the first step is preparing the mold. This involves heating it to the proper temperature and spraying a refractory coating or lubricant. This lubricant keeps the mold warm during the manufacturing process and prevents premature solidification, and helps remove the casting once it has solidified.
The half mold can then be closed and clamped together using high pressure.
Step 2: Injection
After this preparation stage, the molten metal is removed from the furnace and poured directly into the mold through a downward-facing gate. This can be done manually or, in some cases, using an automatic spoon; but the process utilizes gravity. No additional force or pressure is applied. The molten liquid is simply inserted into the mold from an upright vertical position, and due to the natural pull of gravity, it moves down into the casting on its own.
By avoiding the use of high pressure, turbulence is significantly reduced, which in turn helps prevent porosity and leads to the production of smoother components and parts.
Step 3: Cooling
After the molten metal is injected into the casting, it is cooled and solidified. The metal should have enough time to take the mold's shape and must be fully secured before the mold can be released. Removing the casting too early can lead to irreversible defects.
Step 4: Eject
After sufficient time has elapsed, loosen and open the half mold and carefully remove the casting. This can be done manually, or in some cases, an ejector pin is used to safely push the casting out of the gravity die casting machine.
Step 5: Trimming
The final stage of the gravity casting process is trimming. As the metal continues to cool, any scrap metal - including sprues, runners, gates, and flying edges - is expertly removed from the casting. Various tools are used to remove any sharp edges and excess material to create the desired component shape, and the part is typically cleaned before being sent to the customer.
Where to find die casting mold parts?
If you are looking for a reliable precision mold manufacturer for custom die casting mold parts, please contact Shengqi. We are an experienced mold parts supplier with professional equipment and operating technicians to provide you with reliable, high-quality, and accurate die casting parts.
Reprinted from Shengqi Mold Accessories - “What are the die casting process steps?”