摘要
通过对不同时效制度下的常温拉伸性能、硬度、电导率、抗应力腐蚀性能等的测试及微观组织的观察 ,分析了不同时效制度对 74 75铝合金挤压型材的微观组织与综合性能的影响 .研究结果表明 ,单级峰值时效 (T6)具有很高的强度 ,但抗应力腐蚀性能较差 ;双级时效 (T76,T73 )由于晶界析出物呈粗大和孤立分布 ,具有较强的抗应力腐蚀性能 ,但由于过时效时晶内析出相尺寸增大 ,强度有较大幅度的下降 ;沿变形方向带状分布的粗大难熔硬相质点对合金塑性有较大影响 。
7475alloy is a kind of aluminum alloy with high strength. It is mainly used for construction parts of airplanes. The properties, such as tensile properties at room temperature, hardness, conductivity, SCC, and microstructure were systematically studied in this paper. The results show that very high strength, and poor resistance to SCC, were obtained at one step peak aging. The high resistance to SCC was gained at T76 or T73 temper, a little loss of strength followed. It is believed that the large grain boundary precipitates formed in over aged condition are favorable to the resistance to the SCC. Coarse particles existing along deformation bands facilitate the nucleation of cracks, thus have poor effect on the ductility.
出处
《中南工业大学学报》
CSCD
北大核心
2001年第4期394-397,共4页
Journal of Central South University of Technology(Natural Science)
