Fracture failure analysis

The failure of mechanical products can be generally divided into non fracture failure and fracture failure. Non fracture failure generally includes wear failure, corrosion failure, deformation failure and functional degradation failure.            Fracture failure is the most important and dangerous failure of mechanical products, and its classification is complex, generally as follows:            (1) according to the fracture mechanism, it can be divided into slip separation, dimple fracture, creep fracture, cleavage and quasi cleavage fracture, intergranular fracture and fatigue fracture.            (2) according to the fracture path, it can be divided into transgranular, intergranular and mixed crystal fracture.            (3) according to the fracture properties, it can be divided into ductile fracture, brittle fracture and fatigue fracture. In the practice of failure analysis, this classification method is mostly used.            Fracture failure analysis starts from the analysis of macro and micro characteristics of fracture, determines the fracture failure mode, analyzes and studies the relationship between fracture morphology characteristics and material structure and performance, stress state of parts and environmental conditions (such as temperature, medium, etc.), reveals the fracture failure mechanism, causes and laws, and then takes improvement measures and preventive measures.