Type of failure of metallic materials

In recent years, as metal materials have become more widely used in various fields of production and life, the problem of material failure has become increasingly prominent.Material failure mainly refers to mechanical components that fail to perform their intended functions due to changes in the size, shape, or material structure and properties.In summary, they can be roughly divided into three categories: fracture, wear, and corrosion.

1.Fracture

According to the amount of deformation of the material before fracture, it can be divided into ductile fracture and brittle fracture.There are obvious deformation variables and deformation processes before the ductile fracture occurs. There are almost no deformation variables in the brittle fracture, and the fracture process is extremely short. Because of its suddenness, it is often destructive.

In daily production and life, the most common one is fatigue fracture. Under the long-term stress cycle, the material breaks. Secondly, there is a material failure failure mode commonly found in the laboratory, also known as static load fracture. The tensile fracture is such a fracture, and the probability of occurrence during production and life is much smaller than that of fatigue fracture.

2.Abrasion

The machine often works under high-speed, vibration, overload and other working conditions, and the material wears due to surface friction between the machines, which eventually leads to material failure.

Material wear failures can generally be classified 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 the machine, the wear caused by external hard particles or the protrusion of the joint itself is abrasive wear, and the surface material of the metal material is also in the wear range of abrasive wear.

Wear and friction are accompanied by the following measures:First, the contact surface is coated with lubricating oil to improve the smoothness; secondly, the welding machine is used to weld the parts together without affecting the normal production, thereby reducing the relative movement of the parts to reduce friction and thereby reducing wear; Reducing friction reduces the area of the contact surface and the lesser load, thereby reducing friction; in addition, the yield strength of the material can be improved by exploring.

3.Corrosion

The corrosion of metallic materials is due to the chemical and electrochemical reactions of the materials in contact with the surrounding medium.The corrosion of metal materials is various, and it is divided into general corrosion and local corrosion in the macroscopic. In daily corrosion accidents, local corrosion is the most common. Local corrosion can be divided into stress corrosion, pitting corrosion, intergranular corrosion, and gap. Corrosion, etc.


Post time: Jan-24-2019
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