Views: 3 Author: Site Editor Publish Time: 2016-10-11 Origin: Site
Low pressure casting was to make the liquid metal mold filling under pressure, in order to form a way of casting.Due to the pressure is low, it is called a low pressure casting.Its technical process is as follows: in the sealed container containing alloy liquid (such as crucible), dry compressed air is piped in, role in keeping pouring temperature of metal surface, sealed container and mold cavity pressure difference, under the action of gas pressure, the metal liquid along the lift tube, through the gate into the cavity smoothly, and appropriately increase pressure and remain on the surface of the liquid gas pressure in the crucible, make the liquid metal in the high pressure inside the cavity under the action of crystal solidification.Then remove gas pressure on the surface of the liquid, not solidification of liquid metal in the open tube depend on gravity flow back into the crucible, and remove the castings to open type, at this point, a full low pressure casting process is complete.
The advantages of low pressure casting is unique in the following aspects:
1. Low pressure casting pouring process parameters can be adjusted arbitrarily set in technology area, ensures smooth liquid metal filling, reduce or avoid the metal fluid during the filling of churning, impact, splash phenomenon, thereby reducing the oxidation slag formation, avoid or reduce casting defects, improve the quality of the casting;
2. The liquid metal filling under pressure, can improve the liquidity of liquid metal, casting good formability, is beneficial to form the outline clear, smooth surface castings, more advantageous for forming large thin-walled castings.
3. The casting crystal solidification under pressure, and can be fully and casting compact structure, high mechanical performance;
4. Improve the yield of liquid metal riser, generally do not need to make the metal liquid yield is greatly increased, yield could reach 90% in general.
5. Good working conditions;High production efficiency, easy to realize mechanization and automation, and highlight the advantages of low pressure casting.
6. Low pressure casting with wider scope of application of the alloy nameplate, basically can be used in all kinds of casting alloy.Not only for nonferrous alloy casting, and can be used in cast iron, cast steel.Especially for the easy oxidation of nonferrous metal, more show its superior performance, which can effectively prevent the oxidation of the metal liquid produced in the process of casting slag.
7. Low pressure casting on the casting material no special requirements, all that can be used as casting materials, can be used as a low pressure casting mold material.And gravity casting and the application of special casting mold, such as sand, clay sand, sodium silicate sand, resin sand, etc.), shell mold, metal mold, graphite, revestment precision casting shell, ceramic, etc. Can be used.In short, low pressure casting on the casting material requirements are not strictly limited.