摘要
采用室温拉伸和Kahn撕裂测试方法,对一种加入不同含Ce量的新型Al-Cu-Li合金在T6态和T8态峰时效时的力学性能分别进行了测试;同时辅以扫描电镜和透射电镜对其断口形貌和晶界析出相相应的变化规律进行了研究。对所有状态样品的断口扫描照片和晶界析出相情况进行了统计。结果表明:T8态的强度值和UIE值(unit initiation energy)总体高于T6态,中等含Ce量的合金在T8态具有最高的强韧性配合。断口分析中发现:具有韧窝环绕金属间化合物特征的区域所占面积分数的变化趋势与UIE值变化规律一致;晶界分析表明:无析出带宽度的大小、晶界析出相的数密度和有效尺寸的变化决定了样品在不同Ce含量和热处理状态下的断裂阻力和裂纹扩展方式。
The effects of different cerium contents on the mechanical properties of a novel Al-Cu-Li alloy under the peak agedconditions of T6 and T8 were studied by conventional tensile test and Kahn Tear Test. In addition, the grain boundary pre-cipitates and fractography were observed by transmission electron microscopy （TEM） and scanning electron microscope（SEM）. The results show that the UIE and the strength for alloys under T6 condition are generally lower than those for the alloys under T8 condition, while strength-toughness combination has been obtained in alloy 2#（0.15% Ce） under T8（pre-stretched ＋ artificially aged） condition. Meanwhile, a statistic analysis of the microscopic data by Image-Pro Plus （IPP）software, taking into account the effect of cerium content and pre-stretch was carried out. The analysis shows that the largerarea fraction of the combination of dimples and intermetallic particles is corresponding to the higher value of UIE. Thechanges in the precipitate free zone （PFZ） width, grain boundary precipitate number density and grain boundary precipitateeffective size govern the fracture resistance and the crack path of the test alloy under the conditions of the different Ce con-tents and heat treatment.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2014年第5期1061-1066,共6页
Rare Metal Materials and Engineering
基金
Research Foundation of the General Armament Department(6140506)
