L1_2 有序结构 Ni_(74.5)Pd_2Al_(23.5) 合金超点阵内禀层错的形成机制

Formation Mechanism of Superlattice Intrinsic Stacking Faults in L1 2 Ordered Ni 74.5 Pd 2Al 23.5

用ＴＥＭ研究了Ｌ１２长程有序结构Ｎｉ７４．５Ｐｄ２Ａｌ２３．５合金室温变形后的位错结构．结果表明，加Ｐｄ韧化的Ｎｉ７４．５Ｐｄ２Ａｌ２３．５合金室温变形组织中存在着大量超点阵内禀层错．这些层错是从以反相畴态分解的ａ／２〈０１１〉位错通过进一步的分解和反应转变来的．层错的形成是合金变形过程中位错交互作用的二次产物，并不成为影响Ｎｉ７４．５Ｐｄ２Ａｌ２３．５合金变形和韧性的主要因素．

The dislocation structures in L1 2 ordered Ni 74.5 Pd 2Al 23.5 alloy after deformation at room temperature are investigated by TEM. The results show that there exist profusions of superlattice intrinsic stacking faults in the deformed alloy ductlizied by palladium, and the faults are generated from the further dissociation and reaction of APB coupled dislocations. The stacking faults are just the secondary debris formed from the dislocation interaction, which is not a main factor to controll the deformation and ductilization of the Ni 74.5 Pd 2Al 23.5 alloy.