2519铝合金的均匀化热处理

Homogenization heat treatment of 2519 aluminum alloy

本文采用差热扫描分析(DSC)、扫描电镜(SEM)、能谱分析(EDS)和X射线衍射(XRD)等研究了2519铝合金铸态及不同工艺均匀化处理后的显微组织结构和合金元素分布状况。结果表明:合金铸态组织的成分偏析严重,合金元素Cu、Fe多偏聚于晶界处,形成Al2Cu和Al7Cu2Fe共晶相;最佳均匀化温度是530℃,时间是12.15 h。在这种情况下,共晶相Al2Cu溶解充分,溶入晶内基体中的Cu元素浓度最高;在530℃下进行均匀化处理,合金也表现出最佳的力学性能。本文结果为工艺提供了依据与参考。

The microstructure and the alloy elements distribution of as-cast and as-homogenized 2519 Al alloy were studied by differential scanning calorimetry（DSC） analysis,scanning electron microscopy（SEM）,energy dispersive X-ray spectroscopy（EDS） and X-ray diffraction（XRD）.It was found that there was serious dendrite segregation in the as-cast 2519 Al alloy ingot and the alloy elements Cu,Fe congregated in grain boundary to form the eutectic phases Al2Cu and Al7Cu2Fe.After homogenized at 530℃,eutectic phase Al2Cu almost dissolved and the concentration of Cu in the matrix grains reached to the maximum.The tensile test showed that the mechanical property of the alloy homogenized at 530℃ was the best.Besides,the kinetic calculation indicates that the proper time for homogenizing is 12.15 hours at 530℃,which coincides with the experimental result（530 ℃,12 h）.