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本文主要讨论LY12铝合金自然时效及人工时效条件下未加载和疲劳断裂后的蜷线位错问题。室温时效未加载的试样没有位错环和蜷线位错,疲劳断裂的试样有一些不规整的蜷线位错,这种蜷线位错是通过位错攀移而形成的。在未加载240℃时效的试样中存在着许多沿<112>方向伸长的位错环,但在循环载荷作用下,这些环消失并且生成蜷线位错。240℃时效试样的蜷线位错是在循环载荷作用期间位错环同螺位错相互反应产生的。
This article mainly discusses the curl dislocation problem of LY12 aluminum alloy under the natural aging and artificial aging conditions without loading and fatigue fracture. At room temperature, the unloaded specimen had no dislocation loops and curling dislocations. The fatigue ruptured specimens had some irregular curling dislocations which were formed by dislocation climbing. There were many dislocation loops elongated in the <112> direction in the samples aged at 240 ° C, but disappeared under cyclic loading and generated curl dislocations. The curling dislocations of 240 ℃ aging specimens are caused by the mutual reaction of dislocation loops and threading dislocations during cyclic loading.