摘要
采用金相、扫描电镜、透射电镜分析及拉伸性能和断裂韧度试验等手段,研究了7A99铝合金锻件双级时效处理后的组织和性能。结果表明:7A99铝合金锻件经过120℃/4h+165℃/8 h双级时效处理后的抗拉强度、屈服强度、伸长率和电导率分别为548 MPa,513 MPa,12.0%和38.2%IACS;锻件的L-T向断裂韧度为30.5 MPa·m1/2,锻件显示了较好的强韧匹配和耐蚀性;合金的断裂方式为穿晶韧窝断裂方式;主要沉淀相为η'相和η相。
Effects of two-step aging treatment on the microstructure and mechanical properties of 7 A99 forged aluminum alloy were studied using optical microscopy（OM）,scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,tensile test and fracture toughness test. The results show that after 120 ℃/4 h ＋ 165 ℃/8 h two-step aging treatment,the ultimate tensile strength,yield strength,elongation and electrical conductivity are 548 MPa,513 MPa,12. 0% and 38. 2% IACS,respectively.Meanwhile,the L-T toughness fracture is 30. 5 MPa·m1/2. The fracture mode of the alloy is transgranular dimple fracture mechanism,and the major precipitates are η＇ and η phases under the aging condition.
出处
《航空材料学报》
EI
CAS
CSCD
北大核心
2018年第1期54-59,共6页
Journal of Aeronautical Materials
关键词
7A99铝合金
锻件
双级时效
显微组织
力学性能
7A99 aluminum alloy
forging
two-step aging
microstructure
mechanical properties
