摘要
T6态高强7xxx系列铝合金对应力腐蚀开裂敏感。采用回归和再时效热处理(RRA)可以提高其抗应力腐蚀开裂性能而不降低其强度性能。研究了多级热处理工艺对7049铝合金性能和组织的影响。通过电导率测量、DSC分析和TEM组织观察,考察合金在不同热处理态的组织变化。DSC分析表明,RRA处理会导致合金的显微组织发生显著变化,RRA处理态合金的组织与T6和T73态合金的组织明显不同。RRA处理可以使合金保持在T6态的强度且获得T73态的热力学稳定性能。
High strength 7xxx series aluminum alloys in the T6 temper are known to be highly susceptible to stress corrosion cracking (SCC). Retrogression and re-aging (RRA) is a heat treatment by which the resistance to SCC is enhanced without losing yield or tensile strength. The influence of multi-stage heat treatment on the properties and microstructure of AA7049 aluminum alloy was investigated. The microstructure of the alloy in various temper conditions was correlated to the electrical conductivity measurements, DSC analysis and TEM observation. The DSC analysis shows that RRA treatments lead to significant change in the microstructure and the resultant RRA precipitate microstructure is significantly different from both the T6 and T73 microstructures and is able to retain the strength of T6 temper while attaining the thermodynamic stability of the T73 temper.
出处
《中国有色金属学会会刊：英文版》
EI
CSCD
2013年第6期1570-1575,共6页
Transactions of Nonferrous Metals Society of China
