Investment casting has the advantages of high dimensional accuracy, good surface quality and so on. It is a widely used advanced technology with less and no cutting. Simply put, it is to use fusible materials to make fusible models. Therefore, investment casting is a widely used casting method in the field of casting. This casting method reduces the cost and improves the competitiveness of casting enterprises. An important step in investment casting is pouring. What are the common pouring methods of investment casting?

1. Crystallization under pressure

The shell is placed in the pressure tank for pouring. After the end, the pressure tank is immediately closed, and high-pressure air or inert gas is injected into the tank to make the casting solidify under pressure, so as to increase the density of the casting.

2. Vacuum suction pouring

The mold shell is placed in the vacuum pouring box, and the gas in the mold cavity is absorbed through the tiny pores in the mold shell, so that the liquid metal can better fill the mold cavity, the shape of the cavity, improve the casting accuracy, and prevent the shortcomings of insufficient porosity and pouring. This method is more common abroad.

3. Directional crystallization

If the crystalline structure of some investment castings, such as turbine blade and magnetic steel, is columnar crystal arranged in a certain direction, their performance can be greatly improved. Therefore, directional crystallization technology of investment casting is rapidly developing.

4. Hot gravity casting

This is a widely used form of casting in which the shell is removed from a roaster and poured at high temperatures. At this time, the metal in the shell is slow, can fill the mold in the case of high fluidity, so the casting can be a good cavity shape, improve the accuracy of the casting. But the slow casting in the hot mold will make the grain coarse, which reduces the mechanical properties of the casting. When pouring carbon steel castings, but the slower casting surface is easy to oxidize and decarburize, thus reducing the surface hardness, finish and dimensional accuracy of the castings.

The pouring of investment casting is a strict step, and different pouring methods have different characteristics. Therefore, in the process of investment casting, we should choose the appropriate pouring method and cast a good fuse