The origination of cracking of a ZL101 aluminum alloy gearbox during service process was investigated by using metallographic microscope

scanning electron microscope

energy spectrum analysis and other instruments. The results indicate that the crack of the ZL101 aluminum alloy gearbox is characterized by fatigue cracking

and there are stress corrosion cracks at the fatigue source. The main cause of stress corrosion cracking is the presence of corrosive media elements in the working environment of gearbox. Meanwhile

the modification quality of the gearbox is poor

increasing the stress corrosion sensitivity of the base material. In order to avoid the stress corrosion crack of the gearbox

some reasonable preventive measures were provided

such as controlling the content of corrosive medium in the working environment of gearbox and improving the modification quality of gearbox.