The difference between cement sand castings, resin sand castings and vacuum casting parts
The clay wet sand castings casting weight from a few kilograms until tens of kilograms, but the clay dry type of casting production can be weighed dozens of tons.For medium and large castings, cast iron, cast steel can be self hardening sand with resin can be water glass sand production, can obtain the precise size, smooth surface castings, but casting precision, surface roughness, density and microstructure, mechanical properties and material cost of sand casting production is often poor, so when the higher performance requirements of castings, should adopt other casting methods, such as casting (lost wax casting), die casting, low pressure casting.
Vacuum casting is the process of using ventilation molds. Molten metal flows into the mold by air pressure, and then removes air to form a vacuum. The casting process is mainly used for small parts or jewelry with exquisite detailsCompared with the traditional clay sand casting, heat hardening resin sand casting production with low surface roughness, high precision, good quality characteristics, dimensional accuracy of resin sand mold after hardening with good rigidity and high, and not easy to deform, so in the choice of process parameters, mechanical processing you can select a smaller margin, thereby reducing the consumption of metal solution and machining cost, which can improve the dimensional accuracy of castings.
Our country or international, in all casting production in 60 ~ 70% by sand casting is produced, of which about 70% is used in the production of clay sand. The main reason is that the cost of sand casting is low compared with other casting method, simple production process and short production cycle. So as the car engine cylinder body the cylinder head, crankshaft castings are produced using clay wet sand molding process. When the wet type can not meet the requirement to consider the use of clay sand table dry sand, dry sand mold or other sand.
