How to choose the most suitable cast solution to produce investment castings?


There are many casting methods, so, after receiving a casting drawing, how to determine which process method is more suitable? For example, if a product has a curved inner hole, we can make it directly with a mold, or we can use a ceramic core or a soluble core. However, the customer requires high roughness in the hole, which method will you choose? If it is made with a mold, the bending hole must use a combined core to solve the problem that the core cannot be pulled out. Then, a parting line will inevitably appear, and it is necessary to solve the problem of the smooth inner cavity of the wax part by repairing; using a soluble core must be repaired. The soluble core is used to achieve the problem of smooth inner cavity; the ceramic core is used to ensure the quality of the inner cavity through the surface of the ceramic core. The three methods have their own advantages and disadvantages. How to choose? Today, Guangzhou Zhongzhu Machinery, a precision casting manufacturer, will discuss this issue in detail for you.

1.The batch of precision castings. If the batch is large, then it must be produced according to the batch production method. For example: investment casting, metal mold, die casting, sand molding line, etc., must have metal molds; and small batches, there must be molds, but not necessarily metal molds, can be wooden molds, or other materials, But obviously, the service life of the mold is definitely not long. 

2.according to the size of the casting. The size of the casting can indirectly determine the production method of the casting. General precision casting methods have their own bottlenecks. For example, investment casting, large-scale castings will definitely not work. One is limited by the size of the wax injection machine, and the other is limited by the pulp barrel and the method of making shells.

3.Surface roughness and dimensional accuracy. General casting manuals will introduce the surface roughness and dimensional accuracy of castings produced by various casting methods. For example, investment casting and sand casting. The former two indicators (surface roughness and dimensional accuracy) are several levels higher than the latter. Therefore, the corresponding casting method has been basically determined when the customer requests it on the drawing. 

4.The material and structure of precision castings are also a factor in determining the casting method. For example, the structure of castings is very complex, and investment casting may be preferred. Because the advantage of investment casting is that complex parts can be turned into simple parts, and then combined together, there is no parting surface. The material of castings, such as high-temperature alloys, generally adopts investment casting + vacuum furnace.

5.Mechanical properties and metallurgical quality of castings. Strictly speaking, the mechanical properties of the casting will be indicated in the drawing of the casting or the customer's technical agreement, and the corresponding implementation standards will be provided. The standard will provide the corresponding performance of various casting methods, so it can basically determine the casting method of the product. For example, the properties of aluminum alloys are different when cast by metal mold and investment casting methods. The former is greater than the latter. For another example, the metallurgical quality of the metal mold is significantly better than that of investment casting. 

6. The emergence of 3D printing also provides a wider space for the selection of casting methods, which also provides a new way for the selection of later casting methods.

Although there are a thousand casting methods, there may be a hundred that suit you. Find out which one is the most suitable for your creed. The above is the choice of precision casting method, I believe everyone has a certain understanding. Guangzhou Zhongzhu Machinery provides joint development and one-stop customized services from mold manufacturing to precision casting production, and is committed to providing high-quality precision casting for the global high-end manufacturing industry.