What Is a Fine Ceramic?
Materials in the world can be broadly classified into three categories: metallic materials, organic polymer materials, and ceramics. Among these, ceramics are characterized by their high hardness and thermal and chemical stability. Conventional ceramics are called old ceramics and are formed by mixing or firing natural minerals in glass, cement, ceramics, etc. A fine ceramic is made based on chemical processes.
Fine ceramics are defined by their superior mechanical, electronic, physical, and chemical properties, as well as enhanced functionality compared to traditional ceramics, due to precise control of their chemical composition, crystal structure, and particle shape in the manufacturing process. Fine ceramic is said to have originated in 1940 when the application of ceramics to industrial products and the development of new functions began to flourish.
Uses of Fine Ceramics
Fine ceramics are used in a wide range of fields as structural, electronic, engineering, biological, and magnetic materials. For example, they are used in electronic components, industrial equipment, medical devices, and other equipment necessary for manufacturing operations.
In semiconductor and liquid crystal manufacturing equipment, wafers, which are used as elements, are processed using fine ceramics to secure them to the equipment and polish the surfaces.
In medical equipment, fine ceramics are used for surgical instruments, implant parts, and X-ray insulating parts for radiation equipment.
In addition to the above, fine ceramics are applied in information equipment, environmental, energy, aerospace, and electronics industry components.
Characteristics of Fine Ceramics
Fine ceramics are difficult to define but are often defined as “mainly non-metallic inorganic materials” with new functions or properties that are manufactured by precisely controlling their chemical composition, crystal structure, microstructure, grain boundaries, shape, and manufacturing process.
The manufacturing process for fine ceramics begins with the preparation of raw materials, followed by granulation, molding, raw processing, firing, secondary processing, and inspection.
Fine ceramics are made by mixing raw material powders that are more granular or purer than ordinary ceramics, and then using precision equipment to control the structure at the micro to nano level. Fine ceramics are especially useful inside industrial equipment, where heat can easily build up because their thermal properties are superior to those of metals and organic materials.
On the other hand, the disadvantage of fine ceramics is that they are brittle and difficult to process. Because they are formed from powdered raw materials, even a simple drop from a high place can cause them to crack with the impact. This also makes it difficult to process Fine Ceramics into other shapes once they have been formed into one shape.
Types of Fine Ceramics
Fine ceramics can be broadly classified into two types. The first is engineering ceramics, to which a sintering process is added. These ceramics can only be ground and polished, but they have excellent wear resistance. Materials include alumina, silicon nitride, and zirconia.
On the other hand, machinable ceramics are those to which no sintering process is added, and although their strength is weaker than engineering ceramics, they can be machined. Fine ceramics include Hortobell, Macerite, and Makor.
Fine ceramics are also available in a variety of materials, each of which has different properties. Here are some typical ceramic materials.
Alumina (AI2O3)
Alumina is aluminum oxide and is the most common ceramic material. It is characterized by excellent electrical insulation, wear resistance, heat resistance, and chemical stability while being extremely inexpensive.
Zirconia (ZrO2)
Zirconia has excellent strength and toughness and is sometimes used in combination with metals because its thermal expansion coefficient is close to that of metals. It is also used in blades such as scissors, which is difficult to do with ceramics.
Silicon Carbide(SiC)
Silicon carbide is a man-made compound that does not exist naturally; it has excellent strength even at temperatures as high as 1500°C. It is also lightweight and highly corrosion-resistant. Because of these characteristics, it is used as a heat-resistant material in applications such as heater peripheral parts.
There is a wide variety of other types of fine ceramics, including special ceramics such as porous ceramics and transparent ceramics. It is important to select fine ceramics with appropriate materials and properties for the environment in which they will be used.