铸态和锻态高强铝合金热变形组织的演变

采用Gleeble-1500D热力模拟试验机对具有铸态和预锻态初始组织的新型Al-Zn-Mg-Cu高强铝合金试样进行了热压缩试验，分析了该合金铸态和锻态初始组织在热变形过程中的演变。研究结果表明，高温低应变速率条件下，铸态树枝晶粒在热压缩变形拉长的同时，晶内树枝晶界在高温压缩扩散的作用下逐渐消失，转变为粗大均匀且变形拉长的晶粒组织。当压缩变形量很大时，剧烈拉长的晶粒将通过几何动态再结晶得到细化。预锻态试样压缩过程中，适当的温度和应变速率条件下即可发生动态再结晶，形成细小均匀的再结晶新晶粒。

Microstructure Evolution During Hot Deformation of High Strength Aluminum Alloy with As-cast and As-forged Starting Structures

Hot compression tests of new AI-Zn-Mg-Cu alloy with as-cast and as-forged starting structures were carfled out by Gleeble-1500D thermo-mechanical simulator. Microstructure evolution during hot deformation of the alloy with as-cast and as-forged starting structures has been analyzed. The investigation indicates that as-cast dendritic grains elongate under the applied compression conditions, while interdendritic boundaries in as-cast coarse grains disappear gradually due to diffusion at higher temperatures and lower geometric recrystallization occurs and new small grains appear in the pies, dynamic recrystallization occurs at certain temperature and strain strain rates. When the deformation is heavy, severe elongated grains. For as-forged samrate conditions, new small and uniformed re-crystallized grains will be formed when reduction is large enough.