With the increasing requirements for casting quality and the increasingly stringent regulations on environmental protection and cleaner production, it has become the consensus of many casting professionals that silica sand is not the most ideal raw sand for castings. Seeking alternative materials for silica sand has become one of the important research topics in the casting industry. In recent years, many new molding materials have developed rapidly.
We all know that Ceramic Foundry Sand has excellent physical and chemical properties. In addition, is there anything special about it?
Today, let's talk about the thermal properties conducive to casting production.
The table below shows the thermal performance comparison of fused ceramic sand with other common special sand and silica sand.
Thermal properties of Fused Ceramic Sand and Other Common Artificial Sand
Different Special Sand | Refractoriness (℃) | Thermal expansion coefficient (20~1000 ℃) (10-6 / ℃) | Thermal conductivity (w/m • K) (20~1100 ℃) | Specific heat capacity (j/kg • K) | Thermal expansion rate (measured at 1000 ℃/%) |
Fused ceramic sand | >1800 | 6 | 0.5~0.6 | 2210 | 0.13 |
Cerabeads | 1825 | 4.5~6.5 | 0.24~0.5 | 1842 | 0.15 |
Sintered Ceramsite | >1750 | 0.257~0.335 | |||
Chromite sand | 1830 | 0.65 | 1214 | 0.3~0.4 | |
Silica sand | 1710 (SiO2 ≥ 98%) | 23 | 0.7~0.8 | 1130 | 1.5 |
The Excellent Thermal Properties of Fused Ceramic Sand Afford the Following Application Advantages:
1. Fused ceramic sand has high fire resistance and is especially suitable for the casting of alloy steel, stainless steel and other alloys with high pouring temperature, which can reduce the tendency of sand sticking caused by core sand sintering.
2. The thermal expansion coefficient of fused ceramic sand is low, and the thermal expansion curve shows obvious linear growth, without phase transformation expansion, which can reduce or eliminate the casting expansion defects.
3. Fused ceramic sand has high thermal conductivity, large specific heat capacity and high density, which makes its heat storage coefficient relatively large, which is conducive to accelerating the solidification rate of castings and obtaining high-quality castings with dense microstructure.
4. It is stable at high temperature, not wetted by molten metal, not easy to produce chemical sand sticking phenomenon, and can improve the surface quality of castings.