【摘要】 利用液氮球磨、真空热压和挤压工艺制备块体纳米晶Al-Zn-Mg-Cu合金,并对其固溶和时效处理进行研究,得到时效硬度曲线。利用X射线衍射仪和透射电镜对该合金热处理前后的微观组织进行分析,结果表明:块体制备过程中析出的MgZn2可以通过固溶处理使其回溶并在时效后沉淀析出;热压后晶粒尺寸为50~100 nm,热处理后晶粒长大到100 nm,部分晶粒达到200 nm。更多还原

【Abstract】 Bulk nanocrystalline Al-Zn-Mg-Cu alloy was fabricated by cryomilling combined with vacuum hot pressing and extrusion.The aging-curve was obtained.The crystal structures and microstructures before and after heat treatment were investigated by X-ray diffractometry(XRD) and transmission electron microscopy(TEM),respectively.The results show that the deposition(MgZn2) of consolidation can be dissolved again by solid-solution,and precipitated during aging.The grain sizes of the bulk nanocrystalline Al-Zn-Mg-Cu alloy produced by vacuum hot pressing are 50?100 nm,some of them grow to 100 nm even part of them reach 200 nm after heat-treatment.更多还原