The difference between casting and die-casting

Casting refers to the process of injecting molten metal into a mold under the influence of Earth's gravity, also known as gravity casting.
Die casting refers to the process of injecting molten metal into a mold under other external forces (excluding gravity).
The main characteristic of die casting is that the metal liquid fills the cavity under high pressure and high speed, and forms and solidifies under high pressure. The disadvantage of die casting is that during the process of filling the cavity under high pressure and high speed, the air in the cavity is inevitably trapped inside the casting, forming subcutaneous pores. Therefore, aluminum alloy die casting is not suitable for heat treatment, and zinc alloy die casting is not suitable for surface spraying (but can be painted).
Otherwise, during the above treatment and heating, the internal pores of the casting will experience thermal expansion, causing deformation or bubbling of the casting.
In addition, the mechanical cutting allowance for die-casting parts should also be kept small, generally around 0.5mm, which can reduce the weight of the casting, decrease the amount of cutting to reduce costs, and avoid penetrating the surface dense layer, exposing subcutaneous pores, and causing the workpiece to be scrapped

-What is the difference between die-casting and casting?

1. The definitions of die-casting and casting are different:

Die casting is a metal casting process characterized by using the inner cavity of a mold to apply high pressure to melted metal. The mold is usually processed from a stronger alloy, and this process is somewhat similar to injection molding.

Casting is a method of obtaining a part or blank by casting liquid metal into a casting cavity that is suitable for the shape of the part, and allowing it to cool and solidify.

2. The processes of die-casting and casting are different:

The essence of pressure casting (abbreviated as die casting) is the method of filling the mold cavity with liquid or semi liquid metal at a high speed under high pressure, and forming and solidifying the casting under pressure.

The casting process can be divided into three basic parts, namely casting metal preparation, mold preparation, and casting treatment. Casting metal refers to the metal material used in casting production to cast castings. It is an alloy composed mainly of one metal element and added with other metal or non-metal elements, commonly known as casting alloy, mainly including cast iron, cast steel, and cast non-ferrous alloys.

3. The casting accuracy of die-casting and casting is different

Die casting is a precision casting method that produces die cast parts with very small dimensional tolerances and high surface accuracy. In most cases, die cast parts can be assembled and applied without turning, and threaded parts can also be directly cast.

Casting, melting metals, manufacturing molds, and pouring molten metal into the molds to obtain metal parts blanks with certain shapes, sizes, and properties after solidification.

Extended Information

Pressure casting, also known as die casting, is a casting method that involves pouring molten alloy liquid into a pressure chamber, filling the cavity of a steel mold at high speed, and solidifying the alloy liquid under pressure to form a casting. The main characteristics that distinguish die casting from other casting methods are high pressure and high speed.

① Metal liquid is filled into the mold cavity under pressure and crystallizes and solidifies at higher pressures, commonly ranging from 15-100 MPa.

② The metal liquid is filled into the mold cavity at high speed, usually at 10-50 meters per second, and some can even exceed 80 meters per second (the line speed of introducing the mold cavity through the sprue - the sprue speed). Therefore, the filling time of the metal liquid is extremely short, about 0.01-0.2 seconds (depending on the size of the casting) can fill the mold cavity.

-Difference between CNC and Die Casting

Different processing methods:
CNC machining refers to numerical control machining, which is precision mechanical processing under computer digital control. Under this machining process, aluminum shells can achieve some extremely special or complex surface treatments, such as oblique cutting, non penetrating pattern or texture carving, punching at aluminum shell bends, and surface treatment of non flat surfaces.
Die casting refers to the application of high pressure to melted metal using the inner cavity of a mold, in order to create a surface effect similar to that of the mold.
Different processing difficulties:
CNC machining can be said to be able to handle even the most demanding and difficult details.
Die casting can perform some simple punching and pattern forming work, with lower costs compared to CNC machining, but it cannot perform very complex surface treatments.
In summary, we can see that in order to produce and process qualified aluminum shells, it is necessary to choose the corresponding processing technology based on its production needs. At the same time, we also need to consider production costs. In the case where both processing techniques are feasible, we naturally choose which one is more convenient and advantageous, rather than choosing which one looks better, as our actual needs are also important.