Fracture analysis includes two ways: macroscopic analysis and microscopic analysis. Macroscopic analysis only needs magnifying glass and low magnification microscope to observe and analyze the fracture surface at low magnification, to get the general features of the fracture surface, to some extent, to understand the cause of the damage; microscopic analysis is based on macroscopic analysis to further identify the fracture by means of electronic microscopy and other instruments. The influence of path, property, environmental medium and temperature on fracture is discussed, and the cause and mechanism of fracture are further determined.

Macroscopic fracture analysis   

Through macro fracture analysis, the nature of fracture and the whole process of fracture accident can be judged, and the objectives and tasks for further micro fracture analysis can be put forward. Macroscopic fracture analysis is the prerequisite and basis for micro fracture analysis.

Detection equipment: reading microscope, body microscope.

Micro fracture analysis   

Microscopic analysis of fracture is achieved by optical microscopy and scanning electron microscopy. Due to the limitation of depth of field, optical microscopy can only observe roughly cleavage fracture and fatigue fracture, but can not observe transgranular fracture and intergranular fracture with obvious plastic deformation. Even for flat fracture, it is difficult to observe continuously in a large area with low resolution. However, optical microscopy can analyze the structure of the fracture by polarized light, and observe the color change of different regions of the fracture, which plays an important role in the diagnosis of fracture properties. The SEM has a large depth of field, which can be used to study rough fracture surfaces and clear images can be obtained. The magnification can be varied continuously between 10 and 100 thousand times, so that the fracture details can be observed.

Detection equipment: metallographic microscope, scanning electron microscope