摘要
采用OM、SEM及硬度测试等手段研究了均匀化退火处理对Al-4.8Zn-1.6Mg合金微观组织与性能的影响。结果表明:合金铸态组织主要由α-Al和晶界处非平衡低熔点第二相组成。随着退火温度升高或保温时间延长,晶界上熔点较低的非平衡第二相逐渐回溶到α-Al中,偏析现象基本消除,合金元素分布趋于均匀。在退火时间保持不变时,随着退火温度升高,合金硬度逐渐上升。当退火温度不低于315℃时,随退火时间的延长,合金硬度呈下降趋势。当退火温度超过355℃时,随着退火时间的延长,合金硬度逐渐上升。该合金适宜的均匀化退火处理工艺为465℃/24 h。
Influence of homogenized annealing on microstructure evolution and hardness of Al-4. 8Zn-1. 6Mg alloy was studied by means of optical microscopy（ OM）,scanning electron microscopy（ SEM） and hardness test. The results show that the microstructure of as-cast alloy is mainly composed of α-Al matrix and a lot of non-equilibrium second phases in the grain boundary. After homogenized treatment,the second phases with low melting point are gradually dissolved into α（ Al） matrix with the increase of homogenized temperature and homogenization time. The segregation of elements was largely eliminated with uniform microstructure. When the homogenization time keep unchanged,the hardness of alloy gradually rises with the increase of the homogenization temperature. When the homogenization temperature is less than or equal to 315 ℃,the hardness value of the studied alloy gradually decreased with the increase of the homogenization time.When the homogenization temperature exceeds 355 ℃,the hardness value of the studied alloy gradually increased with the increase of the homogenization time. The optimal homogenizing treatment process is 465 ℃/24 h.
出处
《金属热处理》
CAS
CSCD
北大核心
2017年第4期104-109,共6页
Heat Treatment of Metals
基金
湖北省教育厅科学技术研究计划优秀中青年人才项目(Q20161202)
水电机械设备设计与维护湖北省重点实验室开放基金(2016KJX04)
