Al-Li合金中δ′(Al_3Li)颗粒尺寸对位错运动的影响

Effect of Particle Size of δ′(Al_3Li) on Motion of Dislocations in Al-Li Alloys

测定了 Al- Li合金不同条件下δ′(Al3Li)相的颗粒半径和体积分数 ,研究了δ′颗粒尺寸及体积分数对位错运动方式的作用。结果表明 ,如果δ′颗粒的平均尺寸小于临界尺寸 ,δ′颗粒被位错切割 ,反之 ,则形成奥罗万 (Orowan)位错环 ;当相同柏氏矢量的成对位错切割δ′颗粒时 ,会消除先行位错形成的反相畴界 ,当不同柏氏矢量的成对位错切割δ′颗粒时 ,需要增大外力 。

This paper measured the sizes and volume fraction of δ′(Al 3Li) particles in Al Li alloy,which were aged at 150℃ in different times,and studied the effects of δ′ particle′s sizes and volume fraction on motion of dislocations.The results showed that if the average size of the δ′ is less than the critical size,δ′ particles are cut by dislocations,and if not,δ′ particles are Orowen looped by dislocations.When shearing the δ′ particles,dislocation pairs with same burgers vector can remove antiphase boundary,which is formed by first dislocation,and that with different burgers vector needs to increase the applied force,which makes the strength of alloy be further improved.