铸造过程中超声处理对2219铝合金固溶后组织和性能的影响

Effect of Ultrasonic Treatment During Casting on Microstructuer and Properties of 2219 Aluminum Alloy after Solid Solution Treatment

对超声铸造和常规铸造的2219铝合金进行热力学和动力学分析,并研究了两种合金在铸态和不同固溶温度热处理后组织和性能的差异。结果表明：在铸造过程中进行超声处理可以显著减少铸锭中的粗大枝晶组织,并使晶粒得到细化,晶内的第二相也更加细小,分布均匀,密集;超声铸锭对固溶温度的变化更加敏感,当固溶温度较高时,超声铸锭固溶效果更好,硬度也比常规铸锭高。当固溶温度为545℃时,固溶效果最好,超声铸锭硬度达到最大值114.3 HV,比常规铸锭高6.6 HV。超声铸锭中共晶组织尺寸较小,分布均匀,合金的热加工性能好,固溶温度为560℃时,两者都产生过烧,但常规铸锭中存在较多的粗大共晶组织,淬火过程中更容易出现裂纹。

The thermodynamic and kinetic analysis of ultrasonic casting and conventional casting of 2219 aluminum alloy was carried out, and the difference of microstructure and properties of the as-cast alloy and the alloy after solid solution treatment at different temperatures was studied. The results show that ultrasonic treatment in casting process can significantly reduces the coarse dendrites of the ingot and refines the grains, and the second phases in the crystal are finer, evenly distributed and denser. The ultrasonic ingot effect is more sensitive to the solid solution temperature. When the solution temperature is high, the solid solution of ultrasonic ingot is good and the hardness is higher than that of the conventional ingot. When the solution temperature is 545℃, the solid solution is the best, and the hardness of ultrasonic ingot reaches the maximum value of 114.3HV, which is 6.6 HV higher than that of conventional ingot. The size of eutectic structure in ultrasonic ingot is small, the distribution is uniform, and the alloy has good thermal processing property. When the solution temperature is 560 ℃, both of the alloys are over-burned. However, there is a lot of coarse eutectic structure in the conventional ingot, and it is more likely to crack in quenching process.