Casting is an ancient manufacturing method with a history of approximately 6,000 years. With the continuous development of industrial technology, casting technology has become increasingly mature. Nowadays, new casting methods have emerged in the field of casting. Below is a detailed introduction to the advantages and disadvantages of common casting technologies.
Common casting processes include sand casting, investment casting, die casting, low-pressure casting, centrifugal casting, lost-foam casting, and continuous casting.
Sand casting typically relies on silica-based materials. These materials are placed into a pattern of the finished part or a wooden pattern (model), and then sand is packed around the pattern. After removing the pattern, the sand forms a mold cavity for casting.
Lower cost for small-batch production
Compatibility with common metals
Capability to cast large-sized parts
The surface of large castings is rough
Dimensional accuracy is lower than that of other processes, requiring larger tolerances
Castings such as automobile engine blocks, cylinder heads, and crankshafts.
It usually refers to a casting method where a pattern is made from a fusible material. The surface of the pattern is coated with several layers of refractory material to form a shell, and then the pattern is melted and removed from the shell to obtain a mold without a parting surface. This mold can be filled with molten metal. It is commonly known as "lost-wax casting".
High dimensional accuracy of castings
Ability to cast thin-walled parts with complex geometries
Smooth and clean surface of castings
Compatibility with various metals
No parting line tolerances
Higher production costs
Relatively complex process
It can be used for precision parts in aerospace, automotive, hydraulic accessories, and other fields.
Die casting is a process where molten alloy is forced into the cavity of a steel mold at high pressure and high speed. The alloy liquid then solidifies under pressure to form a metal casting.
High casting accuracy
Low surface roughness
High surface hardness of castings
High production efficiency, enabling automated production
Poor stability, making heat treatment difficult
Greater difficulty in die casting complex-shaped castings
Not suitable for small-batch production
Automotive parts, furniture, bathroom hardware, and electronic accessories.
Low-pressure casting is a method in which liquid metal is forced into the mold cavity under pressure to form a casting. It is called low-pressure casting because low pressure is used in the process.
Stable molding process of liquid metal
Smooth surface of castings
High mechanical properties of castings
High molding rate
Liquid metal is prone to oxidation
Castings such as automobile wheels and automobile cylinder heads.
Under the action of centrifugal force, liquid metal is poured into a mold that rotates at a high speed (250~1500 r/min) to fill the mold cavity.
When using centrifugal casting, cores, gating systems, and risers can be omitted
Castings have a compact structure and good mechanical properties
Good filling ability
Not suitable for alloys such as bronze, aluminum, and magnesium
Used for producing pipe castings and wheel disk castings.
It is a new casting method where paraffin or foam patterns, which are similar in size and shape to the desired casting, are assembled to form a pattern cluster. After being coated with refractory paint and dried, the pattern cluster is embedded in dry quartz sand and vibrated. Under negative pressure, the pattern is vaporized and removed. Molten metal then fills the space previously occupied by the pattern, and a casting is formed after solidification and cooling.
High casting accuracy, no need for sand cores, reducing machining time
No parting surface, allowing flexible design with high degree of freedom
Clean production with no pollution
Reduced investment and production costs
Long production cycle
Higher initial cost
Suitable for producing precision castings of various sizes, complex structures, any alloy type, and any production batch. Examples include gray cast iron engine cases and high-manganese steel elbows.
It is a casting method where liquid metal is continuously poured into a continuous casting mold from one end, and the solidified material is continuously pulled out from the other end.
High mechanical properties of castings
Increased production output
Simplified process flow
Continuous casting can be used to produce long castings with a constant cross-section, such as ingots, slabs, billets, pipes, etc., made of steel, iron, copper alloys, aluminum alloys, magnesium alloys, and other materials.
Castings obtained through different casting processes have different accuracies. The initial investment and production efficiency also vary, leading to differences in the final economic benefits. Therefore, to achieve more, faster, better, and more economical results, all aspects should be taken into consideration when selecting a casting process.