What is a casting ?

What is a casting ?


The method of casting liquid metal into a casting cavity suitable for the shape of the part, and after the casting is cooled and solidified, is called casting. Castings obtained by casting are called castings.


Casting structure design: ensure its working performance and mechanical performance requirements, consider the requirements of casting process and alloy casting performance on the casting structure, and whether the casting structure design is reasonable or not has a great impact on the quality, productivity and cost of the casting.


Design main issues and design requirements


The design of the box should first consider the arrangement of the parts in the box and the relationship with the external parts of the box. For example, the shape and size of the box should be determined according to the requirements of the two tops of the lathe. In addition, the following issues should be considered:


⑴, to meet the strength and stiffness requirements. For box parts that are under great stress, meeting the strength is an important issue; but for most boxes, the main indicator for evaluating performance is stiffness, because the stiffness of the box not only affects the normal operation of the transmission parts, but also affects the components. Working precision. Quick and easy automatic selection of castings is included.


⑵, heat dissipation performance and thermal deformation problems. The friction and heat of the parts in the box will change the viscosity of the lubricating oil and affect its lubricating performance; the temperature rise will cause thermal deformation of the box, especially the thermal deformation and thermal stress with uneven temperature distribution, which have a great impact on the accuracy and strength of the box. influences.


  1. The structure design is reasonable. Such as the arrangement of the fulcrum, the arrangement of the ribs, the position of the opening and the design of the connection structure, etc., are all conducive to improving the strength and rigidity of the box.


⑷, good craftsmanship. Including blank manufacturing, machining and heat treatment, assembly adjustment, installation and fixation, hoisting and transportation, maintenance and repair and other aspects of craftsmanship.


⑸, good shape, small quality.


What is casting process?


Casting generally does not apply pressure, does not require high strength of equipment and molds, has small restrictions on product size, and has low internal stress in products. Therefore, the production investment is less, and large-scale parts with excellent performance can be obtained, but the production cycle is long, and mechanical processing must be carried out after molding. On the basis of traditional casting, methods such as pouring, invest casting, pressure casting, spin casting and centrifugal casting are derived.


①Perfusion. The difference between this method and casting is that the product is released from the mold after casting, while the mold is an integral part of the product itself during pouring.


② Embedded casting. Various non-plastic parts are placed in the mold cavity and solidified with the injected liquid material to encapsulate them.


③Pressure casting. Applying a certain pressure to the material during casting is conducive to injecting the viscous material into the die casting mold and shortening the filling time. It is mainly used for epoxy resin casting.


④ Spin casting. After the material is injected into the mold, the mold rotates around a single axis or multiple axes at a low speed, and the material is distributed on the inner wall of the mold cavity by gravity, and shaped by heating and curing. For the manufacture of spherical, tubular and other hollow products.


⑤ Centrifugal casting. A quantitative liquid material is injected into a mold that rotates at a high speed around a single axis and can be heated, and the material is distributed on the inner wall of the mold cavity by centrifugal force, and is solidified into a tubular or hollow cylindrical product by physical or chemical action (see Figure [centrifugation]. casting]). Monolithic cast nylon parts can also be formed by centrifugal casting.

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