本文研究指出,在标准范围内,2124T851合金厚板的断裂韧性随Cu、Mg、Fe、Si含量的增加而明显降低;板材晶粒大小及添加微量硼元素,对断裂韧性无明显影响;而固溶处理是影响断裂韧性的重要因素,但是在185～195℃温度范围内时效9～16小时,对kIc值无明显影响。本文通过用2124T851厚板不同类型试样测量了kIc值,结果表明:三点弯曲和紧凑拉伸直通缺口的kIc值相当,而紧凑型缺口的kIc值则偏低约1.5MN/m3/2。

The results in this research indicated that the fracture toughness decreases obviously with the increase of Cu,Mg,Fe and Si contents within chemical composition range specified in the standard of 2124 T851 aluminium alloy plate, but no obvious influence of grain size in plate and addition of B trace element on fracture toughness was observed.However,solution heat treatment bears an important influence on fracture toughness,the artificial ageing in the range of 185-195℃ for 9-16h has no obvious influence on KIC value of 2124 T851 aluminium alloy plate. For comparison KIC values of various type specimens taken from 2124 T851 plate used for this investigation were measured.The results show that KIC values measured with three-point bend specimens and compact specimens with straight through notch are equivalent,however KIC value of compact specimens with Chevron notch is lower 1.5MN/m3/2 approximately.