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LD2为了解AlN颗粒对不同强度等级的铝合金的增强效果及机制 ,对 40 %体积分数的AlN颗粒增强 10 70、10 6 1、LY12铝合金复合材料拉伸前后的微观组织进行了观察 ,发现拉伸前在基体中存在由热错配引起的高密度位错 ,在AlN颗粒的内部也存在大量的位错 ,拉伸后基体中的位错增殖 ,同时 ,AlN颗粒中的位错亦增多 .力学性能的测试结果表明 ,AlN颗粒对低强度、高塑性的L3纯铝增强率最高 ,中等强度、较高塑性的LD2铝合金不仅有较高的增强率 ,而且保持了一定的塑性 .AlN颗粒对基体的这种选择性主要与AlN颗粒在拉伸过程中产生微量变形 ,从而松弛部分界面应力有关 .LY12基体的塑性较低 ,易产生低应力断裂 ,因此 ,AlN颗粒的增强作用难以得到充分发挥 .
LD2 In order to understand the reinforcing effect and mechanism of AlN particles on aluminum alloy with different strength grades, the microstructure of AlN particles with 40% volume fraction enhanced 10 70,10 6 1 and LY12 aluminum alloy before and after stretching were observed and found that Prior to stretching, there was a high density of dislocations in the matrix due to thermal mismatch, a large number of dislocations were present in the AlN particles, dislocations were propagated in the matrix after stretching, and dislocations in AlN particles increased The mechanical properties of the test results show that, AlN particles of low strength, high plasticity of L3 pure aluminum highest rate of reinforcement, medium strength, high plasticity LD2 aluminum alloy not only has a higher rate of reinforcement, but also maintain a certain degree of plasticity .AlN This selectivity of the particles to the matrix is mainly related to the slight deformation of the AlN particles during the stretching process and thus the relaxation of the interface stress. The plasticity of the LY12 matrix is low and low stress fracture easily occurs. Therefore, the reinforcing effect of the AlN particles is hard to obtain fully use .