The rear axle of the car is an important part of transmitting torque and driving the car forward. In addition to bearing a large torque, when the car starts or brakes, it also bears the impact of the torsional force. Because of its complicated working conditions, the failure of the axle rear axle breakage of the car will occur. Although the rear axle axle of the automobile has few chances of failure due to breakage compared with wear and deformation, the breakage of the axle of the automobile often causes serious mechanical accidents, which have serious consequences and is the most dangerous form of failure.

The fracture of the rear axle of the automobile can be generally divided into four types: ductile fracture, brittle fracture, fatigue fracture and environmental fracture.

1. Ductile fracture

Ductile fracture is also known as plastic fracture or ductile fracture. When the stress caused by the external force exceeds the tensile strength, the fracture caused by plastic deformation is called ductile fracture.

2, brittle fracture

Metal parts or components have no obvious plastic deformation before fracture, and a type of fracture that develops extremely fast is called brittle fracture. It usually occurs suddenly without a predictive signal and is a very dangerous form of fracture.

3, fatigue fracture

However, in actual production, under the long-term effect of repeated and alternating loads, the rear axle of the automobile still breaks. This phenomenon is called fatigue fracture, which is a common and serious failure mode. In the failure of the axle of the rear axle of the automobile, the fatigue fracture accounts for a large proportion, which is about 80% to 90%.

4, environmental break

Under the action of external stress, the crack nucleation and expansion until the sample breaks. The essence is that the elementary process of deformation and fracture is caused by the action of environmental factors (gas phase, liquid phase corrosive medium or hydrogen), which leads to stress brittleness, and thus the phenomenon of destroying failure in this form is collectively referred to as environmental fracture.