Brief analysis of automobile common materials

[Erica Zhu Feilong Jiangli]

There are many kinds of materials used to produce automobiles: iron and steel, non-ferrous metals, plastics, rubber, glass, ceramics and so on. According to statistics, in recent years, the weight composition ratio of the main materials of an ordinary car is approximately 65%-70%, 10%-15% of non-ferrous metals, and 20% of non-metallic materials.

Various new materials, such as light metal materials, composite materials, high-tech synthetic materials, are increasingly used in modern automobiles.

Metal materials have various properties. It has physical and chemical properties, mechanical properties and process properties.

Physical and chemical properties refer to the properties of metal materials under various physical conditions and the ability to resist the erosion of various chemical media. Density: mass per unit volume; thermal conductivity: the ability to conduct heat; electrical conductivity: the ability to conduct electric current; thermal expansion: the ability to increase volume when heated; melting point: the temperature when the solid state becomes liquid; magnetism: the magnetic conductivity of metallic materials is called magnetism; corrosion resistance: metal resists the occurrence of the surrounding medium at room temperature The ability of chemical reactions to be destroyed; oxidation resistance: the ability of metals to resist oxidation at high temperatures.

Mechanical performance refers to the resistance of metallic materials under various loads (external forces). It has the following indicators:

Strength: The ability of metal materials to resist plastic deformation and fracture under load is called strength; the common strength indicators are yield strength and tensile strength

Plasticity: The maximum ability of a metal to produce plastic deformation without being destroyed; commonly used plasticity values are elongation and section shrinkage.

Hardness: The ability of a metal material to resist a more rigid object pressing into its surface, i.e. the ability to resist local plastic deformation; commonly used hardness testing methods include Brinell hardness and Rockwell hardness

Impact toughness: the ability of metal materials to resist failure under impact loading is called impact toughness.