Performance characteristics of ceramics

Performance characteristics of ceramics:

1. Mechanical properties

Ceramic is the material with the best stiffness and highest hardness among engineering materials, and its hardness is mostly above 1500HV. Ceramics have high compressive strength, but low tensile strength and poor plasticity and toughness. Chemical properties ceramics are not easy to oxidize at high temperature, and have good corrosion resistance to acid, alkali and salt.

2. Thermal performance

Ceramic materials generally have a high melting point (mostly above 2000℃) and excellent chemical stability at high temperature; The thermal conductivity of ceramics is lower than that of metal materials, and ceramics are good thermal insulation materials. At the same time, the linear expansion coefficient of ceramic is lower than that of metal, and the ceramic has good dimensional stability when the temperature changes.

3, electrical performance

Most ceramics have good electrical insulation, so they are widely used to make insulating devices of various voltages (1kV~110kV). Ferroelectric ceramics (Barium BaTiO3) have high dielectric constant, can be used to make capacitors, ferroelectric ceramics under the action of external electric field, but also can change the shape, electrical energy into mechanical energy (with the characteristics of piezoelectric materials), can be used as amplifiers, record players, ultrasound, sonar, medical spectrometers, etc. A few ceramics also have semiconductor properties and can be used as rectifiers.

In addition, ceramics have unique optical properties, can be used as solid laser materials, optical fiber materials, optical storage, transparent ceramics can be used in high pressure sodium tube. Magnetic ceramics (ferrites such as MgFe2O4, CuFe2O4, Fe3O4) have a wide range of future applications in recording tapes, records, transformer cores, large computer memory elements.