Al-Mg-Li(01420)合金的时效与断裂

AGING AND FRACTURE IN Al-Mg-Li (01420) ALLOY

本文研究了Al-Mg-Li(01420)超轻型合金的时效微观过程,指出δ’相尺寸与时效时间1/3次方成正比,PFz宽度与时效时间1/2次方成正比;进而分析了时效对合金变形机制及破断特征的影响,指出欠时效时,位错切过δ’相质点;过时效时,位错绕过δ’相质点。峰值时效时,处于位错切过与绕过机制过渡阶段。随时效温度升高和时效时间增长,亚晶界断裂比例增大,合金塑性降低。

Aging of the microstructursal chages in a super-light alloy-01420 were studied. During aging the strengthened particles, δ' phase grow, its size is directly proportional to the third root of the aging time and the width of PFZ is directly proportional to the second root of the aging time. The dislocations cut through δ' phase particles in underaging and bow out δ' particles in overaging. The deformation mechanism transfers from cutting to bowing out at peak aging. The ductility of the alloy decreases with increase in aging time and temperature because the proportion of subgrain boundary fracture increases.