The performance characteristics and application occasions of Fused Resin-coated Ceramic Sand were introduced. Fused Ceramic sand was used as raw sand to produce coated sand, which solved the casting defects of cylinder block oil passage core deformation, cylinder barrel, notch, sand sticking, porosity and wall thickness out of tolerance. Production practice shows that the use of Fused Ceramic Sand can effectively reduce casting defects and improve the quality of cylinder castings.
New Cylinder Body Casting Need Fused Ceramic Sand
With the progress of engine technology, a number of new cylinder bodies have emerged in recent years, which are difficult to carry. For example, there is no sand hole on the side of the water chamber, the oil passage chamber runs through the whole cylinder block and has a large curvature, the water chamber has a narrow and fine water passing structure (4g20b), and even the casting of cylinder barrel and cylinder head integrated casting appears. The high difficulty cylinder block casting structure puts forward new requirements for the performance of coated sand core shooting. In order to adapt to the progress of cylinder casting technology and meet the needs of customers, many foundries have introduced some new molding materials to deal with new problems. Fused Ceramic sand is one of them.
Basic Properties of Fused Ceramic Sand
Fused Ceramic sand, also known as fused ceramsite, is an artificial sand formed by calcination, electrofusion, granulation and screening with bauxite as raw material. The physical and chemical properties of Fused Ceramic sand are different from those of silica sand.
Application of Fused Ceramic sand in the Production of Cylinder Block Castings
Compared with silica sand, Fused Ceramic sand is more suitable for sand casting in terms of thermal expansion, fire resistance and angle coefficient.
Bending Deformation of Long Oil Passage Core
In order to ensure the compact arrangement of the engine, today's engine block structure design, the oil passage cavity runs through the cylinder block from top to bottom, and the crankshaft cavity has the characteristics of bending with shape, and may even be accompanied by bifurcation and other structures. Therefore, the long oil passage core will deform due to its own expansion under the condition of pouring heating, and even cause fracture in serious cases.
According to the above analysis, reducing the expansion rate of molding sand can fundamentally solve the problem of bending deformation.
Taking advantage of the low thermal expansion of Fused Ceramic Sand, which is made into resin-coated sand to solve the problem.