摘要
研究了高温预析出对Al-Zn-Mg-Cu系7055合金的应力腐蚀、晶间腐蚀和剥蚀行为以及时效硬化的影响,并通过对预析出/时效组织的透射电镜观察,阐述了预析出对7055合金各种腐蚀行为和时效硬化的影响。组织观察及腐蚀性能和力学性能测试结果表明:高温预析出处理可使7055合金抗应力腐蚀性能得到明显改善,合金应力腐蚀开裂界限应力强度因子KISCC由7.4MPa·m1/2提高至9.8MPa·m1/2,合金抗拉强度仍能保持在680MPa左右。经高温预析出处理后的7055合金晶间腐蚀、剥蚀敏感性降低,7055合金的剥蚀等级由EC降为EA-。同时,高温预析出处理使晶界析出相粗化显著、离散度增大,晶界平衡析出相的Cu含量为60.18at%,且晶界析出相Cu含量提高。
The influence of high-temperature pre-precipitation on stress corrosion cracking, intergranular corrosion, exfoliation corrosion behaviors and age hardening of 7055 Al-Zn-Mg-Cu aluminum alloy has been investigated in this paper. The transmission electron microscopy have shown that the high-temperature pre-precipitation could enhance the discontinuity of grain boundary precipitates and make Cu content of grain-boundary precipitates reach to 60.18at%. The stress corrosion cracking resistance of 7055 alloys could be improved with non-deteriorated strength and plasticity via the high-temperature pre-precipitation. After pre-precipitating stress intensity factor Kxscc of 7055 alloy raised from 7.4 MPa·m^1/2 to 9.8 MPa·m^1/2. 7055 aluminum alloy with high-temperature pre-precipitation has good intergranular corrosion and exfoliation corrosion resistance property.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2007年第9期1628-1633,共6页
Rare Metal Materials and Engineering
基金
教育部新世纪优秀人才支持计划(NCET-04-0752)
国家重点基础研究发展规划项目(2005CB623704)
国家自然科学基金项目(50471057)
关键词
7055铝合金
高温预析出
剥落腐蚀
晶间腐蚀
应力腐蚀断裂
7055 aluminum alloy
high-temperature pre-precipitation
exfoliation corrosion
intergranular corrosion
stress corrosion cracking
