Selection of aluminum alloy gravity casting shell

Aluminum alloy gravity casting can be divided into two types, one is multi-layer, and the other is solid, but currently the most used in the market is multi-layer.

During the use of aluminum alloy castings, the module is first immersed in a refractory material, and the refractory material is hardened and dried on the object of the module. It must be repeated several times until the thickness of the refractory coating reaches the standard. This is the composite material mentioned above. The shell process, and then let it stand for a period of time to fully harden, and finally can be melted to complete the effect of the multilayer shell.

In the gravity casting of aluminum alloys, in fact, most multilayer shells need sand filling and fillers, and only a few do not need sand filling and fillers. As long as they are simply baked, they can be cast. When we use investment casting, we lose it. Generally speaking, because the volume of the investment mold will increase, during the baking and pouring process, the various parts of the shell will control each other, but it is unlikely to expand and contract uniformly. This may be due to the material of the metal casing and the relatively high temperature chemistry. reaction. This means that due to the mechanical strength, temperature, heat resistance and vibration resistance of the refractories and chemical stability at high temperatures, there are still certain requirements for the properties of the shell, such as shrinkage and expansion of the size. Therefore, the outer shell must also have a certain permeability, so that the inner shell does not exclude gas during pouring. These are all closely related to adhesives and refractory materials as well as the shells used in the manufacturing process.