(北京有色金属研究总院 有色金属制备加工国家重点实验室，北京 100088)
摘 要: 采用硬度、电导率、拉伸性能、撕裂性能等性能测试和差示扫描量热(DSC)、透射电镜(TEM)等分析方法研究单级时效和多级断续时效对高Cu/Mg比Al-Cu-Mg-Ag-Zr合金组织和性能的影响。结果表明：与T6态合金相比，多级断续时效处理在保持合金强度、硬度和电导率同时，显著提高合金的断裂韧性；160 ℃单级时效过程中，Ω和θ′ 相同时析出；断续时效第一级和第三级时效的主要析出相与单级时效的类似，第二级低温时效过程中，θ′ 相明显析出，未出现明显的Ω相析出特征。
关键字: 铝合金；多级断续时效；断裂韧性；析出相
（State Key Laboratory of Nonferrous Metals and Processes,
General Research Institute for Nonferrous Metals, Beijing 100088, China）
Abstract:Hardness, electrical conductivity, tensile, tear test and differential scanning calorimetry (DSC), transmission electron microscopy were used to investigate the effect of single ageing and multi-step ageing process on the microstructure and properties of an Al-Cu-Mg-Ag-Zr alloy with high Cu/Mg ratio. The results show that comparing with the alloy at T6 condition, the hardness, strength and electrical conductivity of the alloy after multi-step ageing keeps unvaried, while the fracture toughness increases significantly. In the single ageing process, Ω and θ′ phases separate out simultaneously. At the first and third step of multi-step ageing, the characteristic of precipitates is not different from that of single ageing. But, θ′ phase separates out without significant characteristic of Ω phase at the second step of low temperature ageing.
Key words: aluminum alloys; multi-step ageing; fracture toughness; precipitates
