热变形参数对铸态高强铝合金微观组织的影响

The Influence of Hot Deformation Parameters on Microstructure Evolution of High Strength Aluminum Alloy with As-cast Starting Structures

文中采用Gleeble-1500D热力模拟试验机对具有铸态初始组织的新型Al-Zn-Mg-Cu高强铝合金试样进行了热压缩试验,分析了热变形参数对该合金铸态组织在热变形过程中演变的影响。研究结果表明,热变形过程中,铸态树枝晶粒组织在热变形过程中变形拉长的同时,晶内树枝晶界在高温压缩扩散的作用下逐渐消失,转变为均匀的晶粒组织;析出相逐渐溶入基体组织;合适的热变形参数条件下,可以获得均匀的锻态组织。

Hot compression tests of new Al-Zn-Mg-Cu alloy with as-cast and as-forged starting structures are carry out by Gleeble-1500 D thermo-mechanical simulator. The author analyzes the influence of hot deformation parameters on microstructure evolution of the high strength aluminum alloy with as-cast starting structure. The investigation indicate 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 transformed to uniform microstructure; Precipitates resolved into matrix during hot deformation gradually; the uniform deformed microstructure can be obtained at proper hot deformation parameters.