Low-pressure casting plays a role in the production of […]
Low-pressure casting plays a role in the production of sand. During operation, a part produced by pressing has special properties and uses. When producing mortgage castings, it is necessary to pay attention to some states inside the mold.
Breathable type for low pressure casting
After the low-pressure casting high-temperature metal liquid is poured into the mold, the mold is filled with a large amount of gas, and these gases must be smoothly discharged from the mold. The performance of the molding sand, which allows gas to pass through, is called gas permeability. Otherwise, the casting will have defects such as pores and insufficient pouring. The gas permeability of the mold is affected by factors such as particle size, clay content, moisture content and sand compactness. The finer the grain size of the sand, the higher the clay and moisture content, the higher the sand compaction, the worse the gas permeability.
Low pressure casting strength
The ability of low-pressure casting sand to resist external damage is called strength, so that it can not collapse during molding, handling, and boxing, and it will not damage the surface of the mold during casting. The strength of the sand should not be too high, otherwise the castings will be defective due to the decrease in gas permeability and concession.
Low-pressure casting fire resistance
The high-temperature metal liquid is poured into the mold to have a strong thermal effect on the mold, so the molding sand should have the ability to resist high-temperature heat, that is, fire resistance. If the fire resistance of the modeling material is poor, the casting is prone to stick sand. The more SiO2 content in the molding sand, the larger the molding sand particles and the better the fire resistance.
Painting process can generally be divided into: painting, dusting and electrophoresis. After the surface treatment of the workpiece, select the appropriate spraying process and equipment for the appearance and corrosion resistance requirements of different workpieces, and pay attention to the control of leveling, drying and cooling, otherwise the product quality will be adversely affected. Under normal circumstances, the painting process can obtain better appearance quality. Spray paint has good gloss, color and weather resistance, and is usually used in automotive exterior coatings, motorcycle fuel tanks and other applications where high appearance is required.