Research On The Microstructures And Properties Of Laser Welding Joint For 1420Aluminium-Lithium Alloy

Laser welding is a kind of new welding tecnologies which is emproved in 60s years 19^th century.Its energy consistency is very high .It is concentrated when it heats the seals.The heat damnification of material is very small.The proportion of the welding line's depth and width is big. It is not effect by electromagnetism power when it is working.The remnants stress of welding joint is low. Most importantly,the welding precision is bigger than normal welding tecnologies and the process material after welding is small,so it belongs to high energy bunchy flow welding tecnologies of high efficency.It is gradually applied to manufact the airial components.On the base of referencing native and foreign works, the paper selects the best technical parameters of weld 1420 aluminium-lithium alloy by laser welding and the technical parameters effect on the quality of welding joint. On the base of these,we have determined the mechanical capabilities of the welding joint ,which contain counteractive intension, tired life and microcosmic rigidity.According to composition analysis of joint,we educe the microstructures of joint.According to the experiment results,we can know that the effection of three technical parameters on the quality of welding joint is different. Frontal and rear weld bead width increase by increasing laser power.Because of inceasing underfill the rear weld bead width degress by increasing laser power after 2000w. Frontal and rear weld bead width degress by increasing welding speed; The effection of defocus on weld line is parabola.It exits the best defocus. Centered by the best defocus,the plus and minus increase can make the weld line to change.The defocus ranges from 4mm to 12mm in the condition of this article. The laser power and welding speed exit definit connection in a certain defocus. The line energy...