sand casting 

investmentcasting

die casting

low pressure casting

centrifugal casting

gravity die casting

vacuumdie casting

squeezing die casting

Lost foam casting

continual casting

（1）Sand Casting

Sand casting: a casting method used to produce castings in a sand mold. Steel, iron and most non-ferrous alloy castings can be obtained by sand casting.

Technical process:

Technical features:

1. It is suitable for making blank with complex shape, especially with complex inner cavity;

2. Wide adaptability and low cost;

3. For some materials with poor plasticity, such as cast iron, etc., sand casting is the only forming process for making parts or blanks.

Application: automobile engine cylinder block, cylinder head, crankshaft and other castings

（2）Investmentcasting

Investment casting: generally, it refers to the casting scheme that the pattern is made of fusible materials, several layers of refractory are coated on the pattern surface to make the pattern shell, and then the pattern is melted and discharged from the pattern shell, so as to obtain the pattern of non parting surface, which can be filled with sand and poured after high temperature roasting. It is often called "lost wax casting".

Process characteristics

advantage:

1. High dimensional and geometric accuracy;

2. High surface roughness;

3. It is able to cast castings with complex appearance and unlimited cast alloys.

Disadvantages: complicated process and high cost

Application: it is suitable for the production of small parts with complex shape, high precision requirements, or difficult to carry out other processing, such as turbine engine blades, etc.

（3）Die Casting

Die casting: high pressure is used to press liquid metal into a precision metal mold cavity at high speed, and the liquid metal is cooled and solidified under the action of pressure to form a casting.

Process characteristics

advantage:

1. High pressure and high flow rate of metal liquid in die casting

2. Good quality, stable size, good interchangeability;

3. High production efficiency, more use of die casting die;

4. It is suitable for mass production with good economic benefits.

Disadvantages:

1. Casting is easy to produce small porosity and shrinkage porosity.

2. The plasticity of die casting is low, so it is not suitable to work under impact load and vibration;

3. During die casting of high melting point alloy, the die life is low, which affects the expansion of die casting production.

Application: die casting was first used in automobile industry and instrument industry, and then gradually expanded to various industries, such as agricultural machinery, machine tool industry, electronic industry, national defense industry, computer, medical equipment, clock, camera, daily hardware and other industries.

（4）Low Pressure Casting

Low pressure casting: it refers to the method that liquid metal fills the mold under the action of low pressure (0.02-0.06mpa), and crystallizes under pressure to form the casting.

Technical Process:

Technical Features:

1. The pressure and speed can be adjusted during pouring, so it can be used for casting various kinds of castings (such as metal mold, sand mold, etc.), casting various alloys and castings of various sizes;

2. With the bottom filling, the liquid metal filling is stable and free of splashing, which can avoid gas entrapment and erosion of the mold wall and core, and improve the qualified rate of the casting;

3. When the casting crystallizes under pressure, the structure of the casting is compact, the outline is clear, the surface is smooth, and the mechanical properties are high;

4. The utilization rate of metal is increased to 90-98% without feeding riser;

5. Low labor intensity, good working conditions, simple equipment, easy to realize mechanization and automation.

Application: Based on traditional products (cylinder head, hub, cylinder frame, etc.).

（5）Centrifugal Casting

Centrifugal casting: it is a casting method of pouring molten metal into a rotating mold, filling the mold under the action of centrifugal force and solidification forming.

Technical Process:

Process Characteristics

Advantage:

1. There is almost no metal consumption in the gating system and riser system, so the production rate is improved;

2. The hollow casting can be produced without core, so the ability of metal filling can be greatly improved

3. The casting has high density, few defects such as porosity and slag inclusion, and high mechanical properties;

4. It is easy to manufacture composite metal castings of cylinder and sleeve.

Disadvantages:

1. There are some limitations when it is used to produce special-shaped castings;

2. The inner hole diameter of the casting is not accurate, the surface of the inner hole is rough, the quality is poor, and the machining allowance is large;

3. The casting is easy to produce specific gravity segregation.

Application:

Centrifugal casting was first used in the production of cast pipes. It is used in metallurgy, mining, transportation, drainage and irrigation machinery, aviation, national defense, automobile and other industries at home and abroad to produce steel, iron and non-ferrous carbon alloy castings. Among them, centrifugal cast iron pipe, cylinder sleeve and shaft sleeve are the most common castings.

（6）Gravity Die Casting

gravity die casting: a molding process in which liquid metal is filled with metal dies by gravity and cooled and solidified in dies.

Technical process:

Process Characteristics

Advantage:

1. The thermal conductivity and heat capacity of the metal mold are large, the cooling speed is fast, the structure of the casting is compact, and the mechanical properties of the metal mold are about 15% higher than that of the sand mold casting.

2. The castings with high dimensional accuracy and low surface roughness can be obtained, and the quality stability is good.

3. Because the sand core is not used or rarely used, the environment is improved, dust and harmful gas are reduced, and labor intensity is reduced.

Disadvantages:

1. The metal mold itself has no air permeability, so certain measures must be taken to export the air in the mold cavity and the gas produced by the sand core;

2. The metal mold is non - yielding, and the casting is easy to crack during solidification;

3. The manufacturing cycle of metal mold is long and the cost is high. Therefore, only in mass production, it can show good economic results.

Application: metal mold casting is not only suitable for mass production of complex shape aluminum alloy, magnesium alloy and other non-ferrous alloy castings, but also suitable for production of iron and steel metal castings, ingots and so on.

（7）Vacuumdie Casting

Vacuum casting: it is an advanced die casting technology that can eliminate or significantly reduce the porosity and dissolved gas in the die casting die cavity during the die casting process, so as to improve the mechanical properties and surface quality of the die casting.

Technical Process:

Process Characteristics

Advantage:

1. Eliminate or reduce the porosity in the die casting, improve the mechanical properties and surface quality of the die casting, and improve the coating performance;

2. To reduce the back pressure of the cavity, the alloy with low specific pressure and poor casting performance can be used, and it is possible to die cast the larger castings with small machine;

3. The filling condition is improved and the thin castings can be die cast;

Disadvantages:

1. The sealing structure of the die is complex, so it is difficult to manufacture and install, so the cost is high;

2. If the vacuum die casting method is not properly controlled, the effect is not very significant.

（8）Squeezing Die Casting

Squeeze casting: it is a method to make liquid or semi-solid metal solidify and flow into shape under high pressure, and directly obtain workpieces or blanks. It has the advantages of high utilization rate of liquid metal, simple working procedure and stable quality. It is an energy-saving and potential metal forming technology.

Technical Process:

Direct squeeze casting: coating spraying, alloy pouring, mold closing, pressurizing, pressure maintaining, pressure releasing, parting, blank demoulding, resetting;

Indirect squeeze casting: spray coating, mold closing, feeding, filling, pressurizing, pressure maintaining, pressure releasing, parting, blank demoulding, resetting.

Technical Features:

1. It can eliminate the internal defects such as porosity, shrinkage and porosity;

2. Low surface roughness and high dimensional accuracy;

3. It can prevent casting crack;

4. It is convenient to realize mechanization and automation.

Application: it can be used to produce all kinds of alloys, such as aluminum alloy, zinc alloy, copper alloy, nodular cast iron, etc.

（9）Lost Foam Casting 

Lost foam casting, also known as real mold casting, is a new type of casting method that combines the wax or foam model bonded to the size and shape of the casting into a model cluster. After coating the refractory coating and drying it, it is embedded in dry quartz sand in the vibration modeling, pouring under negative pressure, making the model gasified, the liquid metal occupies the mold position, and solidified and cooled to form a new casting method.

Process flow: pre foaming → foaming forming → coating soaking → drying → molding → pouring → sand falling → cleaning

Technical features:

1. The casting has high precision and no sand core, which reduces the processing time;

2. No parting surface, flexible design, high degree of freedom;

3. Clean production, no pollution;

4. Reduce investment and production costs.

Application: it is suitable for producing various sizes of precision castings with complex structure, unlimited alloy types and production batches. Such as gray cast iron engine box, high manganese steel elbow, etc.

（10）continual casting

Continuous casting: it is an advanced casting method, the principle of which is to continuously pour molten metal into a special metal mold called the mold, solidify (crust) castings, continuously pull out from the other end of the mold, it can obtain castings of any length or specific length.

Technical process:

Technical features:

1. Because the metal is cooled rapidly, the crystal is compact, the structure is uniform and the mechanical properties are good;

2. Save metal and improve yield;

3. The working procedure is simplified, the molding and other working procedures are avoided, so the labor intensity is reduced, and the required production area is greatly reduced;

4. Continuous casting production is easy to realize mechanization and automation and improve production efficiency.

Application: the continuous casting method can be used to cast long castings with constant section shape such as steel, iron, copper alloy, aluminum alloy, magnesium alloy, etc., such as ingot, slab, billet, tube, etc.