Influence of cryogenic conditions on the properties of welded joints of aluminium-lithium alloys

摘要

By their structural capabilities and mechanical properties, aluminium alloys are the most suitable material for low-temperature service, hence their increasing use for fabricating critical weldments and structures, including aerospace applications. The variations of the mechanical properties and fracture resistance characteristics of welded joints in alloys 1420 (Al-Li-Mg), 1421 (Al-Li-Mg-Sc) and 1460 (Al-Li-Cu) in the termperature range 300 to 20 K were investigated. Tests were made on 4 mm thick plates TIG welded (pulsed arc, argon shielding) and testing was made under uniaxial and eccentric tension. Relation-ships between values of ultimate rupture strength, nominal rupture stress and specific crack propagation energy in the base metal and in and their welded joints were established.