What is advanced ceramics?
Advanced ceramics is also known as technical ceramics or fine ceramics. In Asia, advanced ceramics is usually called industrial ceramics.
Advanced ceramics is quite different from pottery and porcelain, such as ceramic tableware, sanitary pottery, ceramic sanitation, wall tiles and floor tiles for building. Generally, pottery and porcelain is called traditional ceramics.
Advanced ceramics is inorganic & solid material which is non-metal element combined by ionic bonds with covalent bonds.
The powder composition is strictly controlled in the manufacture process, chosen suitable forming method, sintering system and precision machining process to make it materials of perfect physical characteristics.
With better physical performance compared to other materials, advanced ceramics are widely used in fields such as semi-conductors, automobiles and industrial machinery.
Type of advanced ceramic materials
Today, there are a wide range of advanced ceramic materials, including:
Alumina ceramics is the most widely used advanced ceramic material. It offers superior mechanical strength, electrical insulation, high frequency retention, thermal conductivity, heat resistance and corrosion resistance.
Zirconia ceramics is the strongest and toughest ceramic material among advanced ceramics. It is used to create special blades for high-performance scissors ,knives and precision beads, once considered impossible applications.
Steatite is a magnesium silicate material of high electrical resistance at high temperatures, good mechanical strength and a very low dielectric loss factor, which has been used for many decades as insulators or enclosures for electrical parts.
Additionally, steatite ceramics is an excellent material for electrical engineering as it can be readily shape sintered into a wide variety of forms such as washers, bushings, resistor forms and spacers.
Silicon Carbon (SiC)
This artificial compound is synthesized from silica sand and carbon. It provides the best combination of heat resistance, light weight and corrosion resistance, and maintains its strength at high temperatures (1,500℃).
Silicon Nitride (Si2N4)
Among advanced ceramic materials, this lightweight, corrosion resistant material offers the highest level of toughness and thermal shock resistance at high temperature, making it ideal for use in engine components.
Characteristics of Advanced Ceramic Materials
1. Electrical Insulation
Advanced ceramics are insulating materials that do not conduct electricity.
Advanced ceramic materials have become an indispensable material for producing capacitors and electronic components that are widely used in products such as computers, televisions and mobile phones.
Capacitors serve as “traffic controllers” within an electronic circuit by conducting electricity to certain parts, temporarily blocking electricity, or blocking only certain types of electrical signals.
Though advanced ceramics are generally insulating materials that block electricity, semiconductor ceramics can be created to conduct electricity depending on their temperature and the level of voltage applied.
The signature feature of advanced ceramic materials is their extreme hardness; as a result, they have valuable use in high-performance applications.
The hardness of alumina ceramics is nearly 3 times that of stainless steel. This extreme hardness is one of many unique properties that makes advanced ceramics “super materials” for modern technology.
Advanced ceramics possess high rigidity, which is measured by inspecting the elasticity of a specimen after applying a load.
Ceramics is of materials that display less elastic deformation under load possess higher levels of rigidity.
3. Fracture Toughness
Fracture toughness measures a fissured material’s resistance to fracturing .
Though advanced ceramic materials generally possess low fracture toughness, partially-stabilized zirconia, used for products such as scissors and knives, offers significant fracture-toughness improvements.
4. Specific Gravity (Density)
Advanced ceramic materials have lower specific gravity (density) than high-strength metals. Within the same volume, many advanced ceramic materials weigh only half of the metal.
Advanced ceramic materials possess high levels of chemical stability. As a result, advanced ceramic materials are highly resistant to chemical corrosion.
Chemicals — including hydrochloric acid, sulfuric acid, nitric acid, sodium hydroxide and hydrofluoric acid. The results were analyzed, and materials that dissolved in relatively large quantities were determined to be more sensitive to chemicals.
1. Heat Resistance
Conventional ceramic materials, including bricks and tiles, are well known for their ability to withstand high temperatures. Alumina ceramics begins to melt or decompose at temperatures above 1,800℃, much higher than the melting point of metal materials.
2. Thermal Expansion
When materials are heated, their size and volume increase in small increments, in a phenomenon known as thermal expansion. The coefficient ratio of thermal expansion indicates how much a material expands per 1℃ rise in temperature. Different material has different thermal expansion. Advanced ceramic materials have low coefficients of thermal expansion — less than half those of stainless steels.
3. Thermal Conductivity
The property of heat transmitted through a material is called thermal conductivity.
Advanced ceramic materials offer a wide range of thermal conductivity.
Among advanced ceramic materials, some materials possess high levels of conductivity and transfer heat well, while others possess low levels of conductivity and transfer less heat.
Silicon carbide transfer heat particularly well while zirconia ceramics block heat effectively and the coefficient of thermal conductivity is low — about 1/10 that of stainless steel.
Advanced ceramic production process
Raw material milling & mixing, spraying & drying
The raw materials used in making advanced ceramics (also known as “technical ceramics”) include inorganic solid powders with precisely controlled purity, particle size and distribution. These raw materials are formulated for specific properties and functionality, then mixed with a binding agent or binder.
Typical shaping method:
Shaped green body is fired at extreme heat in temperature-controlled kilns.
Firing removes the moisture and binders. With additional firing, powder particles are sintered together and the products shrink due to reduced porosity. This process results in products of extreme density and hardness.
Inspection & Packing
Advanced Ceramic Materials Applications
Advanced ceramic materials is a type of new material of wide range applications.
Advanced ceramic materials provide the perfect solution and a cost-effective, high performance alternative to traditional materials such as metals, plastics and glass.
Advanced ceramic materials can be made into different forms (ceramic parts of different shapes, different dimensions and different tolerance) for different industries, such as
Electrical components (backing material, mounting brackets, insulators and resistors);
Rotors, combustors, ceramic brake and exhaust;
Laser positioning mirrors and packaging;
Protection unit (ceramic armor &bulletproof board);
Ceramic furnace radiant heaters;
Ceramic hot gas filtration;
Ceramic fuel cell membranes;
Ceramic diesel engine filters and fuel injector parts;
Textile and wire thread guides;
Abrasion ceramic liners;
Ceramics grinding media.