Classification of investment casting sand
Investment sand is mainly divided into quartz sand and special sand according to the composition of minerals. Quartz sand is commonly known as silica sand. Let's understand the difference between silica sand and non silica sand.
The main mineral composition of silica sand is quartz and the main chemical composition is SiO2.
1. Natural silicon sand: because of its different chemical composition and particle size composition, it is used for molding sand and core sand of non-ferrous alloy castings, iron castings and small and medium steel castings respectively.
2. Choose natural silicon sand: used for all kinds of casting sand and core sand with organic matter as binder.
3. Silica sand: used for molding sand and core sand of investment casting, furnace lining or steel casting.
There are many kinds of non siliceous sand and their uses are different.
1. Limestone sand: broken from limestone, the main mineral composition is CaCO3, used for molding sand and core sand of steel castings.
2. Sand: the main mineral composition is ZrO2 · SiO2, which is used for core sand of large steel castings and alloy steel castings, surface sand of sand mold, or powder as coating.
3. Sand: the main mineral composition is MgO, which is used for surface sand and core sand of high manganese steel castings. Its powder can be used as coating.
4. Iron ore: the main mineral composition is chromite FeO · Cr2O3, which is used for surface sand and core sand of large or special steel castings. Its powder can be used as coating.
5. Sand: the main mineral composition is corundum α - Al2O3, which is used as shell material for investment casting and ceramic mold casting.
6. Olivine sand: the main mineral composition is olivine (MgFe) 2sio4, which is used for molding sand and core sand of iron castings, non-ferrous alloy castings and high manganese steel castings.
7. Pearl sand: the main mineral composition is Al2O3, which has the advantages of high temperature resistance, easy collapsing, good grain shape, acid and alkali resistance, low crushing rate and strong reusability. It is an ideal molding material for cast iron, cast steel, cast copper, cast aluminum and core sand. Its cost performance is better than that of chrome ore sand and zircon sand.