The basic principle of Gravity Casting Machine is simply to use the principle of standard air pressure to pressurize the product and give it a solid shape. Although it sounds simple, its production process is not so easy. In detail, it first releases 0.01~0.05Mpa of air pressure or inert gas pressure on the surface of the molten soup in the closed maintenance furnace. Then the molten soup rises through the soup feed pipe (riser pipe) immersed in the molten soup and is pressed into the upper mold connected to the furnace.

1. There are many processes that can make metal materials into desired products, such as casting, forging, extrusion, rolling, drawing, stamping, cutting, powder metallurgy, etc. Among them, casting is the most basic and most commonly used process.

2. The molten metal is poured into a hollow mold made of high-temperature resistant materials, and the desired shape of the product is obtained after condensation. This is casting. The obtained product is a casting.

3. Casting can be divided into ferrous metal casting (including cast iron and cast steel) and non-ferrous metal casting (including aluminum alloy, copper alloy, zinc alloy, magnesium alloy, etc.) according to the material of the casting. Precision casting factories specialize in non-ferrous metal casting, with a focus on aluminum alloy and zinc alloy casting.

4. Casting can be divided into sand casting and metal casting according to the material of the Casting mold. Precision casting factories are proficient in both casting processes and design and manufacture these two types of casting molds by themselves.

5. Casting can also be divided into gravity casting and pressure casting according to the pouring process of molten metal. Gravity casting refers to the process of injecting molten metal into a mold under the action of the earth's gravity, also known as casting. Broadly speaking, gravity casting includes sand casting, metal mold casting, investment casting, lost foam casting, mud mold casting, etc.; narrowly speaking, gravity casting refers specifically to metal mold casting. Pressure casting refers to the process of injecting molten metal into a mold under the action of other external forces (excluding gravity). Die casting in a broad sense includes die casting and vacuum casting, low-pressure casting, centrifugal casting, etc. in die casting machines; in a narrow sense, die casting refers specifically to metal mold die casting in die casting machines, referred to as die casting. Precision casting factories have long been engaged in gravity casting of sand molds and metal molds. These casting processes are currently the most commonly used and relatively cheap in non-ferrous metal casting.

Gravity casting often uses its penetration detection and coloring detection. It soaks or sprays colored liquid with high penetration ability on the surface of the casting. The penetrant enters the open defect, quickly wipes off the surface penetration liquid layer, and then sprays the easy-to-dry indicator (also called developer) on the surface of the casting. After the penetrant remaining in the open defect is sucked out, the indicator is dyed, and then the shape, size and distribution of the defect can be reflected.