The results show that residual stress and serious metallurgical defects near the fracture initiation site are the failure cause of the gearbox output shaft.

The result indicates that the metallurgical defects in the casting is the reason that cause the brittle fracture of the reinforced bars, and the change of the environmental temperature only has the function of catalysis.

Aiming at the current existing problems of study and fabrication of national aluminum sheet used for easy-open can without being pay more attention to the effects of intrinsic metallurgical defects, a new idea to link organically with hot deformation process in the study of the aluminum sheet used for easy-open can has been put forward by author.

The bolts was fractured after used for two years, resulting from bad working and serious metallurgical defects , such as segregation and inclusion.

The metallurgical defects,such as high density inclusion and low density inclusion,always appear in the titanium alloys,which are the fatigue crack sources in the titanium components and lower the application life of the components.

The experimetal results show that the premature break of drive gear shaft is attributed to the metallurgical defect in raw 20CrMo steel and abnormal structure present in hardened case as well as lower core hardness.

WEDM crackle is posterity defects, which causes the presence of waster and extra manufacture costs, so effective methods must be used to eliminated material metallurgy defects and WEDM crackle, then, die quality and life cycle can be improved largely, manufacture costs can be lowered, and competency can be increased, these changes bring good economic benef.

The metallurgy defects of 6063 alloy are discussed.

Microcomputer application in the analyzing of metal rupture and metal defect—The research of MFAS V1.0 and MFAS V1.0 software;