Different Types of Casting Process

• Posted by andrew ci June 16, 2022 Filed in Business #Casting Process  54 views
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  What is casting?

  Liquid metal is poured into a mold cavity that matches the shape and size of the part. The production method that waits for it to cool and solidify to obtain the blank or part is usually called metal liquid forming or casting.

  

  Types of casting process

  1.  Sand casting

  A casting method for producing castings in a sand mold. Steel, iron and most nonferrous alloy castings can be obtained by sand casting.

  Technical characteristics:

  Suitable for making blanks with complex shapes, especially with complex inner cavity;

  Wide adaptability and low cost;

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

  Applications: Automotive engine block, cylinder head, crankshaft and other castings

  1.  Investment casting

  A kind of casting method that usually refers to making patterns in fusible materials, covering the surface of the pattern with several layers of refractory materials, and then melting the pattern out of the mold shell to obtain a mold without a parting surface, which can be filled after baking at high temperature.

  Advantages:

  High dimensional accuracy and geometric accuracy;

  High surface roughness;

  It can cast complex castings, and cast alloys are not restricted.

  Disadvantages: complicated procedures and high cost

  Applications:

  It is suitable for the production of small parts with complex shapes, high precision requirements, or other processing that is difficult to perform, such as turbine engine blades.

  1.  Die casting

  The high-pressure metal liquid is pressed into a precision metal mold cavity at high speed, and the metal liquid is cooled and solidified under pressure to form a casting.

  Advantages:

  The metal liquid is subjected to high pressure andthe flow rate is fast during die casting.

  Good product quality, stable size and good interchangeability.

  High production efficiency and die casting molds can be used for many times.

  It is suitable for mass production with good economic benefits.

  Disadvantages:

  The casting is prone to produce fine pores and shrinkage.

  The die-casting parts have low plasticity and should not work under impact load and vibration.

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

  Applications: Die castings were first applied in the automotive industry and the instrument industry, and then gradually expanded to various industries, such as agricultural machinery, machine tool industry, electronics industry, national defense industry, computers, medical equipment, clocks, cameras and daily hardware.

  1.  Low pressure casting

  Refers to the method of making liquid metal fill a mold under a low pressure (0.02 – 0.06MPa) and crystallize under pressure to form a casting.

  Technical characteristics:

  The pressure and speed during pouring can be adjusted, so it can be applied to various casting molds (such as metal molds and sand molds), casting various alloys and castings of various sizes.

  Bottom-injection filling is adopted, the filling of metal liquid is stable, and there is no splash phenomenon, which can avoid the involvement of gas and the erosion of the molding wall and core, which improves the qualification rate of castings.

  The casting crystallizes under pressure. The casting has a dense structure, a clear outline, a smooth surface, and high mechanical properties. It is particularly beneficial for the casting of large thin-walled parts.

  Eliminate the need to fill up the riser and increase the metal utilization rate to 90-98%.

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

  Application: Mainly used in traditional products (cylinder head, hub, cylinder frame, etc.).