Process Description

With advances in technology and the foundry industry, the rapid development of different mold casting method to prepare different content. To the most widely used sand casting, for example, cast molding material preparation including the preparation and modeling made two core tasks. Sand casting used to form the core of a variety of manufacturing raw materials, such as casting sand, sand binders and other accessories, and prepared by them into the sand, core sand, paint and other materials collectively known as the modeling task of molding materials prepared in accordance with castings requirements, the nature of metal, select the appropriate raw sand, binders and accessories, then a certain percentage of them have certain properties mixed into the sand and core sand. Equipment commonly used in sand grinding wheel mixer, counter-flow mixer and the mixer blade groove. The latter is designed for mixing chemicals Sand design, continuous mixing, fast.
 
Modeling manufacturing core is based on casting requirements modeling method in determining the good, ready to form the basis of the material carried. Casting accuracy and all the economic effects of the production process, depending on the working procedure. In many modern foundry, the model core are made to achieve a mechanized or automated. Commonly used core sand molding equipment made of high, medium and low pressure molding machine, throw sand machine, without me squeeze molding machines, core shooting machine, cold and hot-box machine.
 
Cooling from the casting mold casting after being removed with the gate, riser, metal burrs, Phi front harmony model line, sand casting sand casting still clinging, it must clean up process. Equipment for such work polishing, shot blasting machine, pouring riser cutting machines. Sand casting off the sand clean-up is less a process of working conditions, so the choice modeling method, should be taken into account to create convenient conditions for cleaning off the sand. Some castings for special requirements, but also by post-casting processing, such as heat treatment, plastic surgery, anti-rust treatment, roughing, etc..
 
Casting is a more economical method of rough shape, the shape of complex parts for more show its economy. Such as automotive engine cylinder blocks and heads, ship propellers and other fine works of art. Some difficulty cutting the parts, such as nickel-based alloy gas turbine parts can not be formed without casting method.
 
In addition, the casting of the part size and weight to adapt to a wide range of metal types of almost unlimited; parts in general mechanical properties with the same time, with wear, corrosion resistance, shock-absorbing ability, it is the other metal forming methods such as forging , rolling, welding, punching, etc. can not do. Therefore, casting methods used in the machine manufacturing industry produced rough parts, the volume and tonnage, is the largest so far.
 
Casting materials often use a variety of metals, coke, wood, plastic, gas and liquid fuels, modeling materials. Equipment requirements of various metal smelting furnace, a sand with a variety of sand mixer, a model built using a variety of core molding machine, core making machine, with clean sand casting off used machines, shot blasting machine and so on. Also for special foundry machinery and equipment, and many transportation and material handling equipment.
 
Casting and other processes have different characteristics, mainly adaptability, needed materials and equipment and more, pollute the environment. Casting will produce dust, harmful gases and noise pollution on the environment than other mechanical manufacturing process to more serious measures are needed to control it.
 
For casting engineers and mechanical engineers, structural design, heat treatment is a very meaningful and a very high value to improve the material quality of the method, by heat treatment can change or influence the organization and the nature of cast iron, while access to higher strength, hardness, and improve its wear resistance and so on.
 
As the objectives are different, so many types of heat treatment, the basic principal can be divided into two categories, first is the organizational structure will not change by heat treatment or not and should not change, the second is the fundamental change in the organizational structure of those . The first heat treatment process used to eliminate internal stress, and this internal stress series in the casting process because of different cooling conditions and conditions caused. Organization, strength and other mechanical properties, etc., do not change significantly due to heat treatment. For the second class treatment, the Al Qaeda significant changes have taken place, can be broadly divided into five categories: (1) softening annealing: The main purpose is the decomposition of carbide, will reduce its hardness, and improve processing performance, and for spherical stone cast iron, its purpose is to obtain iron is rather high fertility organizations. (2) normalization of treatment: mainly used to improve or to complete a wave of products to be cast iron bodies uniform mechanical properties. (3) quenching: mainly to a higher hardness and wear resistance, strength, simultaneous to the high wear characteristics of the surface. (4) Surface hardening: surface hardening layer were mainly the same time, the surface wear characteristics are very high. (5) precipitation hardening: The main is to obtain high strength and elongation are not drastic changes have taken place.