Failure type of metal material
Time：2018-06-19
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In recent years, with the increasingly widespread application of metal materials in various fields of production and life, the problem of material failure has also become prominent. Material failure is mainly referred to mechanical components caused by changes in the size, shape or material structure and performance of the mechanical components cannot complete the intended function. To sum up, it can be roughly divided into three categories: Fracture, Wear and Tear and Corrosion.
1. Fracture
According to the amount of material deformation before fracture, it can be divided into ductile fracture and brittle fracture. Before the occurrence of ductile fracture, there will be obvious deformation and deformation processes. In brittle fracture, there is almost no deformation, and the fracture process is very short. Because of its sudden nature, it is often destructive.
In the daily production and life, the most common is the fatigue fracture. Under the long-term stress cycle, the material breaks. Second, there is a material fracture failure mode commonly found in the laboratory, also known as the static load fracture. Tensile breakage belongs to this kind of breakage. Compared to fatigue breakage, the probability of occurrence in production is much smaller.
2. Wear and Tear
Mechanical parts often work under high-speed, vibration, and overload conditions. The material wears out due to surface friction and eventually leads to material failure.
The wear failure of materials can usually be divided into five categories: abrasive wear, adhesive wear, fatigue wear, corrosion wear and fretting wear. Among them, abrasive wear is the most common. During the operation of a machine part, the abrasive wear is caused by the intervention of external hard particles or the protrusion of the connector. The surface of the metal material is also classified as abrasive wear.
Wear and friction always happen together. The following measures are commonly used in production: First, lubricate the contact surface to increase the degree of smoothness and cleanliness. Second, weld the components together with a welding machine without affecting normal production. Relative motion reduces friction and thus reduces wear. Third, to reduce friction, the area of the contact surface and the smaller loads can be reduced to reduce the friction; in addition, the yield strength of the material can also be explored.
3. Corrosion
Corrosion of metallic materials is due to chemical and electrochemical reactions between the materials and the surrounding medium. Corrosion of metal materials is various and can be divided into general corrosion and local corrosion on a macroscopic scale. In all kinds of daily corrosion accidents, local corrosion is the most common, and local corrosion can be divided into stress corrosion, hole corrosion, intergranular corrosion, and cracks corrosion and so on.
1. Fracture
According to the amount of material deformation before fracture, it can be divided into ductile fracture and brittle fracture. Before the occurrence of ductile fracture, there will be obvious deformation and deformation processes. In brittle fracture, there is almost no deformation, and the fracture process is very short. Because of its sudden nature, it is often destructive.
In the daily production and life, the most common is the fatigue fracture. Under the long-term stress cycle, the material breaks. Second, there is a material fracture failure mode commonly found in the laboratory, also known as the static load fracture. Tensile breakage belongs to this kind of breakage. Compared to fatigue breakage, the probability of occurrence in production is much smaller.
2. Wear and Tear
Mechanical parts often work under high-speed, vibration, and overload conditions. The material wears out due to surface friction and eventually leads to material failure.
The wear failure of materials can usually be divided into five categories: abrasive wear, adhesive wear, fatigue wear, corrosion wear and fretting wear. Among them, abrasive wear is the most common. During the operation of a machine part, the abrasive wear is caused by the intervention of external hard particles or the protrusion of the connector. The surface of the metal material is also classified as abrasive wear.
Wear and friction always happen together. The following measures are commonly used in production: First, lubricate the contact surface to increase the degree of smoothness and cleanliness. Second, weld the components together with a welding machine without affecting normal production. Relative motion reduces friction and thus reduces wear. Third, to reduce friction, the area of the contact surface and the smaller loads can be reduced to reduce the friction; in addition, the yield strength of the material can also be explored.
3. Corrosion
Corrosion of metallic materials is due to chemical and electrochemical reactions between the materials and the surrounding medium. Corrosion of metal materials is various and can be divided into general corrosion and local corrosion on a macroscopic scale. In all kinds of daily corrosion accidents, local corrosion is the most common, and local corrosion can be divided into stress corrosion, hole corrosion, intergranular corrosion, and cracks corrosion and so on.
