CASTING

Die casting is a kind of casting method in which liquid or semi-liquid metal or alloy is poured into the pressure chamber of a die casting machine, so that it fills the cavity under high pressure and high speed, and is formed and crystallized under high pressure to obtain a casting.

Due to the high specific pressure of the molten metal, the flow rate is very high and the filling time is extremely short. High pressure and high speed are the two characteristics of the liquid metal filling and forming process during die casting, and they are also the most fundamental differences between die casting and other casting methods.

Advantages and Shortcomings of Die Casting

Advantages

• The product quality is good. Due to the fast heat conduction of the die-casting mold, the metal cools quickly, and at the same time crystallizes under pressure, the casting has a fine grain structure and a solid surface, which improves the strength and hardness of the casting. In addition, the casting is dimensionally stable, which can produce thin-walled and complex parts.
• High productivity, the die-casting mold could be used for many times.
• Good economic benefits. The machining allowance of die-casting parts is small, and it can be used generally only by finishing and reaming, thus saving a lot of raw materials, processing equipment and man-hours.

Shortcomings

• The die-casting mold has complex structure, high manufacturing cost and long preparation period, so it is only suitable for mass production of shaped products.
• The die casting speed is high, the gas in the cavity is difficult to completely discharge, and the metal mold solidifies quickly in the mold, so it is practically impossible to feed. That’s why the casting is prone to small pores and shrinkage porosity. The thicker the casting wall, the more serious this defect is. Therefore, die casting is generally only suitable for castings with a wall thickness below 6mm.
• The plasticity of die castings is low, and it is not suitable to work under pressure and vibration.
• In addition, when the high melting point alloy is die-casting, the life of the mold is low, which affects the expansion of die-casting production. In summary, die casting is suitable for the production of non-ferrous alloys, small, thin-walled and complex castings. Considering the advantages of other technologies of die casting, when the required number of castings is 2000-3000 pieces, die casting can be considered.

Typical Application Areas

• Health Care: complex medical devices such as ultrasound systems, pacemakers, dialysis equipment, medical robots, monitoring devices, and hospital bed gearboxes.
• Energy: piping, drilling machinery, valves, flow controls, filtration devices, impellers, and more.
• Mining: excavators, drills, draglines, crushers, and specialized heavy-duty vehicles.
• Mechanical and Plant Engineering: machine tools, conveyors, pumps, lifting equipment, and compressors.

Investment casting is a manufacturing process in which a molten material is poured into a mold, which contains a hollow cavity of the desired shape, and then allowed to solidify.