2618铝合金新型固溶处理工艺研究

Study on New Solid Solution Treatment Technology of 2618 Aluminum Alloy

对不同固溶处理方式后的2618铝合金挤压态显微组织进行了观察与分析,并测定了固溶处理前后的硬度变化。结果表明:挤压态2618铝合金主要是由α-Al、Al9FeNi、Al7Cu2Fe和少量细小的Al2Cu相组成;在恒温+升温固溶处理时,随着固溶温度升高,2618铝合金的硬度先升高后降低,在547℃时达到最大值,比恒温固溶处理2618铝合金的硬度提高6.1%,且合金未出现晶粒粗化和过烧现象。在恒温+升温+降温升温循环固溶处理时,随着循环次数的增加,2618铝合金的硬度同样先升高后降低,在2次循环固溶处理时达到最大值,比恒温固溶处理2618铝合金的硬度提高14.5%,合金也未出现晶粒粗化和过烧现象。恒温+升温固溶处理或恒温+升温+降温循环固溶处理能有效提高2618铝合金的固溶效果和力学性能。

The microstructure of 2618 aluminum alloy extruded state after different solution treatment was observed and analyzed.The hardness changes before and after solution treatment were measured.The results show that the extruded 2618 aluminum alloy is mainly composed ofα-Al,Al9FeNi,Al7Cu2Fe and small amount of Al2Cu phases.In solution treatment at fixing temperature+temperature rise,the hardness of 2618 aluminum alloy increases first and then decreases with the increase of solid solution temperature.At 547℃,the hardness of 2618 aluminum alloy is increased by 6.1%compared with that of constant temperature solution treatment,and no grain coarsening and over-firing occur in the alloy.In solution treatment at fixing temperature+temperature rise+cooling and heating cycle,with the increase of cycle times,the hardness of 2618 aluminum alloy also increases first and then decreases.The maximum value is reached in two cycles of solid solution treatment.The hardness of 2618 aluminum alloy treated with fixing temperature solution is increased by 14.5%.There is no grain coarsening and over-burning in the alloy.Solid solution treatment of fixing temperature+temperature rise or fixing temperature+temperature rise+cooling and heating cycle can effectively improve the solid solution effect and mechanical properties of 2618 aluminum alloy.