Views: 1 Author: Site Editor Publish Time: 2016-09-22 Origin: Site
Casting is a metal humans master earlier hot working process, about 6000 years of history.China between 1700 ~ 1700 b.c. Has entered the heyday of bronze casting, craft has reached a quite high level.Defines how to foundry industry?Casting is a liquid metal casting to match the shape of parts with the casting cavity, after waiting for the cooling and solidification, for parts or method of blank.Was originally cast material for more solid but heated to liquid metal (example: copper, iron, aluminum, tin, lead, etc.), the materials of mold can be sand, metal and ceramics.According to different requirements, the use of the methods will also be different.Definition and classification is introduced in foundry industry are as follows.
The casting industry definition
Casting industry market survey analysis, casting is a metal melting into meet certain requirements of the liquid is poured into the mold, after cooling solidification, men get a predetermined shape, size and performance of the casting process.Casting blank for almost forming, and achieve the goal of free machining or a small amount of processing to reduce the cost and to a certain extent, reduce the production time. Casting is one of the foundation of modern equipment manufacturing industry.
The casting industry classification
1 ordinary sand mold casting, the use of sand as mold material, also known as sand casting, aluminum casting, including green sand mold, dry sand mold and chemical hardening sand mold 3 classes, but not all are available in the casting.Advantage is lower cost, because the sand mold use reusable;Defect is mold making time-consuming, mold itself can not be repeated use, must be destroyed after the finished product can be achieved.
1.1 sand mold (core) casting methods: wet self-hardening sand, sodium silicate sand, resin sand mould and dry type and table dry type, type casting, negative pressure model.
1.2 sand core manufacturing method is according to the sand core production batch size, shape, and choose the specific production conditions.In production, in general can be divided into manual core and core making machine.
2.1 metal mould casting process
Of the raw materials of high melting point metal production mold.The subdivided into gravity casting, low pressure casting method and high pressure casting method.
Under the control of the melting point of mold, can be molten metal is also limited.
2.2 lost wax casting method.
This method can be as the outer membrane casting method and the solid casting method.
To copy wax casting items required first, and then dip pool containing ceramic (or silica sol) and stay dry, make with wax replica of the complex on a layer of ceramic outer membrane, repeat steps until enough to support outer membrane casting process (about 1/4 inch to 1/8 inch), then the wax melting mould, and out of mold.Then mold need to high temperature for many times, enhance behind the hardness could be used in the casting.
This method has good accuracy, can be used as a high melting point metal, such as titanium casting.But because of the price is quite high, ceramic and many times required for production of heating and complex, so the cost is expensive.