Al-Zn-Mg-Cu合金铣削表面变形层的微观组织和织构

发布时间：2018-10-20 14:41

【摘要】：利用透射电镜(TEM)技术以及配套的旋进电子衍射(PED)技术对铣削Al-Zn-Mg-Cu合金表面变形层的微观组织和织构进行研究。结果表明:表面变形层是由最表层的等轴纳米晶/超细晶层和亚表层的层状纳米晶/超细晶层组成,晶粒周围分布大量的粗大晶界析出相(GBPs);最表层再结晶的纳米晶/超细晶的存在说明除了位错运动,动态再结晶也在晶粒细化过程中发挥作用;与原始粗晶相比,加工表面变形层内GBPs和晶内析出相(GIPs)尺寸和密度明显的不同是由于热机械作用诱发析出相重新分布;表面变形层的织构类型为由近铜型织构{112}111、旋转立方织构{001}110和F型织构{111}112组成的混合型织构,铣削加工过程引入的表面剧烈剪切变形是上述织构形成的主要原因。
[Abstract]:The microstructure and texture of the surface deformation layer of milling Al-Zn-Mg-Cu alloy were studied by means of transmission electron microscopy (TEM) technique and a complete set of precession electron diffraction (PED) technique. The results show that the surface deformation layer is composed of the topmost equiaxed nanocrystalline / ultrafine crystal layer and the layered nanocrystalline / ultrafine crystal layer in the subsurface layer. The existence of the nanocrystalline / ultrafine crystal, which is the most superficial recrystallization of (GBPs); precipitated phase at the grain boundary, indicates that in addition to dislocation movement, dynamic recrystallization also plays a role in the grain refinement process, and compared with the original coarse grain, dynamic recrystallization also plays an important role in the grain refinement process. The obvious difference in the size and density of GBPs and precipitated phase (GIPs) in the deformed layer of machined surface is due to the redistribution of precipitated phase induced by thermo-mechanical action. The texture types of the surface deformation layer are mixed texture consisting of near-copper texture {112} 111, rotating cubic texture {001} 110 and F-type texture {111} 112. The main reason for the formation of these textures is the severe shear deformation of the surface introduced during milling.
【作者单位】：西北工业大学材料学院;
【基金】：973项目资助
【分类号】：TG146.21;TG54

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