China Aluminum Alloy Castings
China Aluminum Alloy Castings
Robotic Arm Accessory
Part NameRobotic Arm Accessory
ProcessAluminium sand casting
Types of base sands used in sand casting process :
Base sand is the type used to make the mold or core without any binder. Because it does not have a binder it will not bond together and is not usable in this state.
Silica (SiO2) sand is the sand found on a beach and is also the most commonly used sand. It is made by either crushing sandstone or taken from natural occurring locations, such as beaches and river beds. The fusion point of pure silica is 1,760 掳C (3,200 掳F), however the sands used have a lower melting point due to impurities. For high melting point casting, such as steels, a minimum of 98% pure silica sand must be used; however for lower melting point metals, such as cast iron and non-ferrous metals, a lower purity sand can be used (between 94 and 98% pure).
Silica sand is the most commonly used sand because of its great abundance, and, thus, low cost (therein being its greatest advantage). Its disadvantages are high thermal expansion, which can cause casting defects with high melting point metals, and low thermal conductivity, which can lead to unsound casting. It also cannot be used with certain basic metals because it will chemically interact with the metal, forming surface defects. Finally, it releases silica particulates during the pour, risking silicosis in foundry workers.
Olivine is a mixture of orthosilicates of iron and magnesium from the mineral dunite. Its main advantage is that it is free from silica, therefore it can be used with basic metals, such as manganese steels. Other advantages include a low thermal expansion, high thermal conductivity, and high fusion point. Finally, it is safer to use than silica, therefore it is popular in Europe.
Chromite sand is a solid solution of spinels. Its advantages are a low percentage of silica, a very high fusion point (1,850 掳C (3,360 掳F)), and a very high thermal conductivity. Its disadvantage is its costliness, therefore it's only used with expensive alloy steel casting and to make cores.
Zircon sand is a compound of approximately two-thirds zirconium oxide (Zr2O) and one-third silica. It has the highest fusion point of all the base sands at 2,600 掳C (4,710 掳F), a very low thermal expansion, and a high thermal conductivity. Because of these good properties it is commonly used when casting alloy steels and other expensive alloys. It is also used as a mold wash (a coating applied to the molding cavity) to improve surface finish. However, it is expensive and not readily available.
Chamotte is made by calcining fire clay (Al2O3-SiO2) above 1,100 掳C (2,010 掳F). Its fusion point is 1,750 掳C (3,180 掳F) and has low thermal expansion. It is the second cheapest sand, however it is still twice as expensive as silica. Its disadvantages are very coarse grains, which result in a poor surface finish, and it is limited to dry sand molding. Mold washes are used to overcome the surface finish problems. This sand is usually used when casting large steel workpieces.
Modern casting production methods can manufacture thin and accurate molds鈥攐f a material superficially resembling papier-m芒ch茅, such as is used in egg cartons, but that is refractory in nature鈥攖hat are then supported by some means, such as dry sand surrounded by a box, during the casting process. Due to the higher accuracy it is possible to make thinner and hence lighter castings, because extra metal need not be present to allow for variations in the molds. These thin-mold casting methods have been used since the 1960s in the manufacture of cast-iron engine blocks and cylinder heads for automotive applications.
Binders are added to a base sand to bond the sand particles together (i.e. it is the glue that holds the mold together).
Clay and water
A mixture of clay and water is the most commonly used binder. There are two types of clay commonly used: bentonite and kaolinite, with the former being the most common.
Oils, such as linseed oil, other vegetable oils and marine oils, used to be used as a binder, however due to their increasing cost, they have been mostly phased out. The oil also required careful baking at 100 to 200 掳C (212 to 392 掳F) to cure (if overheated, the oil becomes brittle, wasting the mold).
Resin binders are natural or synthetic high melting point gums. The two common types used are urea formaldehyde (UF) and phenol formaldehyde (PF) resins. PF resins have a higher heat resistance than UF resins and cost less. There are also cold-set resins, which use a catalyst instead of a heat to cure the binder. Resin binders are quite popular because different properties can be achieved by mixing with various additives. Other advantages include good collapsibility, low gassing, and they leave a good surface finish on the casting.
MDI (methylene diphenyl diisocyanate) is also a commonly used binder resin in the foundry core process.
Sodium silicate [Na2SiO3 or (Na2O)(SiO2)] is a high strength binder used with silica molding sand. To cure the binder, carbon dioxide gas is used,
The advantage to this binder is that it can be used at room temperature and is fast. The disadvantage is that its high strength leads to shakeout difficulties and possibly hot tears in the casting.
This part is made by aluminum sand casting process
1. light weight to save energy
2. High Mechanical property to ensure security
3. Lower cost
4. Long experience in this area
Zhejiang Baoshi Casting Co., Ltd was established in 1995, specialized in aluminum alloy gravity casting ,low pressure casting and sand casting .
Production facility:we have gravity casting machines , low pressure casting machines, resin sand molding line,continuous melting furnaces,T6 heat treatment facilities,shot blasting machines,sand core machines,ultrasonic cleaner etc.
Machining facility:we have vertical CNC(DMG.DOOSAN) , horizontal CNC(DOOSAN), numerical control lathes and gantry machining center.
Testing facility:we have x-ray nondestructive detectoscope , Metallographic testing equipment锛宻pectrometer,universal testing machine,hardness tester,leakage testing machine,CMM and resin sand analysis equipments .
Project development: we have Anycasting simulation system to shorten the OTS lead time and improve the product鈥檚 quality.
The company has passed IATF 16949 international certIfication .
RT certification :
PT certification :
Q1.What is the difference between t4 and t6 aluminum?
T4 is also slightly less expensive than T6 and has a slightly lower ultimate tensile strength and yield strength, with a higher elongation percentage, which increases the formability of the T4 temper. Aluminum sheet 6061 T4 is also cost friendlier and has improved formability over T6.
Q2. What is the difference between t5 and t6 aluminum?
The main difference between T5 and T6 is in strength, the strength of T6 is higher than that of T5, and the performance in other aspects is similar. In terms of price, due to differences in the production process, aluminum plate T6 is slightly higher than T5.
Q3.What are the three stages of heat treatment?
2.0.0 STAGES of HEAT TREATMENT
You accomplish heat treatment in three major stages: 鈥?Stage l 鈥?Heat the metal slowly to ensure a uniform temperature. Stage 2 鈥?Soak (hold) the metal at a given temperature for a given time. Stage 3 鈥?Cool the metal to room temperature.
Q4.What is heat treatment used for?
Heat treatment is a controlled process used to alter the microstructure of metals and alloys such as steel and aluminium to impart properties which benefit the working life of a component, for example increased surface hardness, temperature resistance, ductility and strength.
Q5锛歐hat is heat treatment process?
In simple terms, heat treatment is the process of heating the metal, holding it at that temperature, and then cooling it back. During the process, the metal part will undergo changes in its mechanical properties. This is because the high temperature alters the microstructure of the metal.
Q6.What is hardening heat treatment?
The hardening process consists of heating the components above the critical (normalizing) temperature, holding at this temperature for one hour per inch of thickness cooling at a rate fast enough to allow the material to transform to a much harder, stronger structure, and then tempering.China Aluminum Alloy Castings