The process and precautions of investment casting

Investment casting, also known as lost wax casting, includes processes such as pressing wax, wax repairing, tree forming, dipping, melting wax, casting molten metal, and post-processing. The currently popular Investment Casting Die Casting with Zinc/Aluminum also belongs to the finished products of investment casting. Investment Casting is to use a certain object to make a mold for the part to be cast and then coat the mold with mud, which is mud mold. After the clay mold is dry, put it in hot water to melt the inner wax mold. Take out the clay mold that has melted the wax mold and then bake it into a pottery mold. Once roasted. Generally, the pouring port is left when the mud mold is made, and then the molten metal is poured from the pouring port. After cooling, the required parts are made. Next, let's take a look at the specific process and precautions of investment casting.

Here is the content list:

l The process of Investment Casting:

l Precautions during Investment Casting

The process of Investment Casting

The first is the degreasing of the module. To improve the ability of the coating to wet the surface of the module, the oil stain on the surface of the module needs to be removed when the wax-based mold material is used to make the investment mold. The second step is to apply paint and sand to the module. Before applying the paint, the paint should be stirred evenly to reduce the precipitation of refractory materials in the paint bucket as much as possible. Adjust the viscosity or specific gravity of the paint so that the paint can Fill and wet the investment mold well. When hanging the paint, soak the module in the paint and shake it up and down, so that the paint can well wet the investment mold and evenly cover the surface of the module. After the paint is applied, sanding can be carried out. The third step is drying and hardening of the shell: after each layer of the shell is coated, it must be dried and hardened, so that the binder in the coating changes from sol to jelly, and connects the refractory material. Because of the different heating methods of investment casting, there are many dewaxing methods. Finally, before the roasting, the de-molded shell is buried in the sand in the box, and then loaded into the furnace for roasting, and then pouring can be carried out.

Precautions during Investment Casting

The defects of Investment Casting are divided into surface and internal defects and out-of-tolerance size and roughness. Surface and internal defects refer to under-casting, cold insulation, shrinkage, pores, slag inclusion, thermal cracking, cold cracking, etc.; size and roughness out of tolerance mainly include elongation and deformation of castings. The surface and internal defects are mainly related to the pouring temperature of the alloy liquid, the baking temperature of the shell and the preparation process, the design of the pouring system and the casting structure, and other factors. The main reason for the casting size and roughness of Investment Casting is out of tolerance is that the design of the die is related to the use and wear, the structure of the casting, the roasting and strength of the shell, and the cleaning of the casting. For example, when there is under-casting in investment casting, the reasons may be that the low pouring temperature and the mold shell temperature reduce the fluidity of the molten metal, the casting wall is too thin, the design of the gating system is unreasonable, the shell baking is not sufficient or the air permeability is poor, and the pouring speed. If it is too slow and the pouring is insufficient, at this time, the problem should be solved in a targeted manner and the defects should be eliminated according to the specific structure of the casting and the related processes involved.

The above is the specific process and precautions of investment casting. After reading the matters, you should want to find a trustworthy company. If you are interested in Investment Casting Die Casting with Zinc/Aluminum. You can choose to log in to our company's website https://www.compass-casting.com/ to view it. We welcome you and look forward to having the opportunity to cooperate with you.