喷射成形Al-Zn-Mg-Cu系超高强度铝合金热处理制度的实验研究

Experimental Investigation on Heat Treatment of Spray-Forming Ultrahigh Strength Al-Zn-Mg-Cu Alloys

研究了喷射成形Al-Zn-Mg-Cu系超高强度铝合金的沉积态和挤压态的组织,对挤压态合金进行了固溶处理和时效处理,得到了时效硬度曲线,并进行了力学性能测试.结果显示:沉积态合金孔隙较多;挤压态合金内存在大量的颗粒,经能谱分析为富铜相;固溶温度达到490℃时,晶界出现熔化现象.时效硬度曲线表明:采用120℃时效,在15～25h之间达到硬度峰值;采用135℃时效,达到硬度峰值的时间与合金的成分有关,随着Zn含量的增加,达到硬度峰值的时间变短,而抗拉强度基本稳定在700MPa芹右.

The microstructures of as-deposited and extruded ultrahigh strength aluminum alloys by spray-forming were investigated. The aging-curves and tensile properties were tested after solid-solution treatment and aging treatment. The result shows that in as-deposited alloys, many porosities are obvious. In extruded alloys, however, there are large amount of Cu-rich particles. The solid-solution treatment temperature should not be higher than 490°C because much of grain-boundaries melt in this temperature. At 120°C, the time to obtain hardness peaks ranges from 15 to 25 h. At 135°C, the relationship is obvious between the time and the composition of the alloys: The more Zn contented, the less the time; the tensile strength of the alloys keeps on about 700 MPa.