A brief analysis of the difference between pottery and porcelain, traditional ceramics and special ceramics

Ceramics is a general term for pottery and porcelain, and there are many concepts about ceramics. According to different uses and performances, ceramics have many names. How should we simply distinguish them? This article will share with readers the identification method:

Difference Between Pottery and Porcelain

Pottery: An item made of clay as a body, processed by hand, wheeled, molded and dried, and then fired in a kiln. Porcelain: Porcelain is a kind of object made of porcelain stone, kaolin, etc., which is mixed, shaped and calcined with glaze or painted surface. In fact, porcelain is a silicate material developed on the basis of pottery, which is whiter, finer, denser and has better performance than pottery.

The difference between pottery and porcelain lies in the use of materials and the firing temperature, both of which are indispensable. Pottery can be made of various mineral clays including china clay. The firing temperature is low, mostly between 700 and 1000 °C. Observing the matrix under a microscope, there are very few glass-phase mullite crystals, in other words, there is no porcelain, and the sound of percussion is dull. Porcelain is made of china clay with high alumina content, that is, aged clay. The firing temperature of the porcelain is at least 1100°C, the body is basically porcelainized, there are a large number of mullite crystals in the microscopic observation, the porosity and water absorption are low, and the sound of percussion is clear.

The difference between traditional ceramics and special ceramics

Traditional ceramics are also called ordinary ceramics. According to their uses, they can be divided into daily-use ceramics, art ceramics, building and sanitary ceramics, etc. And special ceramics, also known as advanced ceramics (advanced ceramics), fine ceramics, high-performance ceramics, high-tech ceramics and so on.

Traditional ceramics are made from natural silicate minerals (porcelain stone, clay, feldspar, quartz sand, etc.) through traditional techniques such as crushing, grinding, blending, shaping, drying, and calcining. Advanced ceramics are made of high-purity, ultra-fine synthetic inorganic compounds (with or without silicide) as raw materials, and are sintered by precision-controlled advanced processes. They have a finer structure and better performance than traditional ceramics. A generation of ceramics.

Special ceramics can be divided into structural ceramics (engineering ceramics) and functional ceramics according to their performance. The performance of structural ceramics mainly refers to mechanical properties such as strength, stiffness, hardness, elasticity, and toughness; while the performance of functional ceramics mainly refers to optical, electrical, magnetic, thermal, acoustic and other functional properties; according to chemical composition, it can be divided into oxides and non-oxides. The former includes various oxides and oxo acid salts; the latter includes nitrides, carbides, borides and the like. The former is generally used for functional ceramics, while the latter is used for engineering ceramics. Some varieties are used in the manufacture of engine parts, auto parts, TV sets, hair dryers, fire alarms, high temperature extrusion dies, etc. It can also be used to manufacture high temperature resistant nozzles, which are suitable for the needs of national defense.

Mainly distinguish traditional ceramics and special ceramics from the following aspects

1. In terms of raw materials, it breaks through the boundaries of traditional Chinese ceramics with clay as the main raw material. Special ceramics generally use oxides, nitrides, silicides, borides, carbides, etc. as the main raw materials. The main difference is that the various chemical composition, morphology, particle size and distribution of special ceramic raw materials can be precisely controlled.

2. In terms of composition, the composition of traditional ceramics is determined by the composition of clay, so ceramics from different origins and kilns have different textures. Since the raw materials of special ceramics are pure compounds, the ingredients are determined by artificial proportions, and the quality of their properties is determined by the purity and craftsmanship of the raw materials, not by the place of origin.

3. In the customized process, advanced methods such as isostatic pressing, injection molding and vapor deposition are used in molding, so that the green body size with uniform density distribution and relatively accurate can be obtained, and the green body density is also greatly improved; the sintering method breaks through the traditional Ceramics take the furnace as the main production method, and vacuum sintering, protective atmosphere sintering, hot pressing, hot static pressing, reaction sintering and self-propagating high temperature sintering are widely used.

4. In terms of performance, special ceramics have different special properties and functions, such as high strength, high hardness, corrosion resistance, electrical conductivity, insulation and special functions in all aspects of magnetism, electricity, light, sound, and biological engineering, so that the It has been widely used in high temperature, machinery, electronics, aerospace, medical engineering.

With the development of material science and the improvement of manufacturing technology, the internal structure of ceramics has gradually become refined and densified, which greatly improves the material properties, resulting in the emergence of new special functions. In the process of its development, a large number of multifunctional, High-performance special ceramics came into being.