Present Situation of Silica Sand
Silica sand has rich sources, high refractoriness, and is not wetted with metal melt. Today, it still accounts for more than 90% of the original casting sand. With the continuous improvement of casting quality, comprehensive cost control, environmental protection and other requirements, the shortcomings of silica sand itself are becoming more and more prominent: poor thermal stability, easy to form veining defects due to phase transformation. At high temperature, it is easy to react with iron oxide to form iron olivine, resulting in sand sticking. The refractoriness is relatively low, and it is easy to react with manganese oxide to form slag, which is difficult to adapt to the casting of medium high alloy steel and high manganese steel. It is easy to break, and the dust generated after breathing may cause workers to suffer from silicosis.
Foundry Industry Needs Molding Sand With Better Performance
Foundry production increasingly needs raw sand with better performance. Since the 1940s, foundry workers have developed and popularized dozens of special foundry sand. Special sand generally has the characteristics of high refractoriness, good thermal conductivity, small thermal expansion and strong resistance to slag erosion. Zircon sand, chromite sand, olivine sand, magnesia, etc. are widely used. They are mainly used in the casting of alloy steel or carbon steel that. They are often used in coated sand, mold surface sand, coatings, special cores, etc. due to the unsatisfactory particle shape, difficulty in recycling and other reasons, the overall effect is poor, and the whole production line is rarely used. Since the end of last century, some enterprises and research institutions in Japan, China, Germany and other countries have used kaolin and bauxite as raw materials to produce ceramic spherical sand with different compositions and phases through granulation, sintering, melting, air crushing and other processes. In addition to the above advantages of natural special sand, it also has the advantages of less binder consumption, good fluidity, good air permeability. It has the characteristics of high strength, crushing resistance and adaptability to various molding and core making processes, and has been rapidly popularized and applied in the past decade. Among them, fused ceramic sand has the best comprehensive performance and the most extensive application.
Basic information of Fused Ceramic Sand
Fused ceramic sand is a new type of artificial sand with spherical particles and excellent properties. It has been used in high manganese steel castings, large steel castings and other aspects, and has achieved satisfactory results.
Characteristics of Fused Ceramic Sand
Fused ceramic sand has the following characteristics:
1. Fluidity: Fused ceramic sand is a spherical particle with smooth surface and no concave convex veins. It has good fluidity and filling performance, and is easy to compact during molding, which can obtain good formability and mold strength.
2. Low thermal expansion coefficient: Fused ceramic sand has a small thermal expansion coefficient and a thermal expansion rate of 0.13, which can prevent the cracks and surface defects caused by the expansion defects of castings, and produce castings with high dimensional accuracy and high yield.
3. Air permeability: Fused ceramic sand can maintain air permeability during modeling, and its air permeability depends on the size, particle size distribution, particle shape and binder type of sand particles.
4. High refractoriness: the main component of Fused ceramic sand is aluminum oxide, which is stable without chemical change, and the fire resistance is 1820 ℃.
5. Reusability: Fused ceramic sand has good crushing resistance, small volume, high strength, and is not easy to crack. It can be used repeatedly, reducing the amount of waste sand and increasing the amount of recycled sand, thus reducing the loss of sand mold.
Application of Fused Ceramic Sand
Fused ceramic sand is widely used in resin sand (furan resin, alkaline phenolic resin), sodium silicate sand, coated sand and other sand molds. Suitable for various metal castings: such as carbon steel, alloy steel (high manganese steel, high chromium cast iron), cast iron, cast copper, etc. It is suitable for the production of castings with binder and metal materials, with easy sand cleaning and sand mixing. The application of fused ceramic sand in investment casting shows that Fused ceramic sand has high fire resistance and can replace zircon sand in the surface sanding of investment casting of steel castings. It can also be used in lost foam casting process as lost foam filling sand.
Green casting is the development trend of the foundry industry in the future. As a new type of artificial sand, fused ceramic sand will become a vital foundry sand in the foundry industry. The advantages of fused ceramic sand, such as heat resistance, low expansion rate, crushing resistance and good collapsibility, will play a greater role in the new era of sustainable development.
Professional Fused Ceramic Sand Manufacturer
Sanmenxia Qiangxin foundry materials Co., Ltd. is an enterprise specializing in the production and sales of high-end casting molding materials - fused ceramic sand for casting (ceramic foundry sand). With innovation and R & D as the core, the company cooperates with colleges and universities to establish an industry university research base. The product testing equipment is perfect, and the product quality is controlled from the source to ensure that the product is qualified. It is committed to providing high-quality fused ceramic sand for foundry manufacturers.