【摘要】 高强度铝合金沿晶界断裂过程中的声发射信号特征反映了材料沿轧制方向的宏观性能。在带有预制裂纹的双悬臂梁 (DCB)试样中 ,裂纹失稳扩展前 ,先有一短距离的韧窝状穿晶撕裂的稳态裂纹扩展。稳态裂纹扩展起始于K1C并发射出许多幅值超过阈值 35dB的信号。当稳态裂纹扩展至Kmax时 ,便出现失稳的沿晶开裂。对稳态及失稳的裂纹扩展两种情况 ,其累计声发射能量均与宏观断裂能呈线性关系更多还原

【Abstract】 The acoustic emission characteristics reflect the macroscopic properties along rolling direction of high strength aluminum alloy. A short ,stable crack extension by dimpled, transgranular tearing was observed in tests on pre-cracked DCB specimens. The specimens were found to emit strongly above a 35dB threshold when stable crack extension started at K 1C.Unstable,intergranular crack along grain boundary extension was observed after the stable crack extension at K max. The cumulative energy of acoustic emission events were found to be linearly relative to the macroscopic fracture energy for both stable and unstable crack extension.更多还原