放電等離子燒結制備Al-Zn-Mg-Cu納米晶合金的組織

Microstructure of a bulk nanocrystalline Al-Zn-Mg-Cu alloy prepared by cryomilling and spark plasma sintering

摘要: 利用低溫液氮球磨和放電等離子燒結工藝制備了塊體納米晶Al-Zn-Mg-Cu合金.采用X射線衍射(XRD)技術分析了材料的晶粒尺寸和微觀應變,利用透射電鏡(TEM)研究了合金微觀組織的演變.結果表明:采用放電等離子燒結法制備的7000系納米鋁合金具有兩種不同的納米晶結構,以晶粒尺寸50~100nm的等軸晶為主,少量200~400nm的大晶粒為輔;燒結過程中發生再結晶及第二相析出,析出的第二相以η(MgZn₂)為主,θ(Al₂Cu)以及S(Al₂CuMg)為輔.

Abstract: A bulk nanocrystalline Al-Zn-Mg-Cu alloy was produced by cryomilling and spark plasma sintering. The grain size, the microstrain, phase transformation and microstructure of this alloy were investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results show that the bulk nanocrystalline 7000 aluminum alloy prepared by spark plasma sintering has two types of distinctive nanostructures-primarily equiaxed grains with diameters of 50-100 nm, and a few of larger grains with diameters of 200-400 nm. The precipitate of second phases, mainly including η (MgZn₂) and a few θ (Al₂Cu) and S(Al₂CuMg), and recrystallization of the bulk nanocrystalline 7000 aluminum alloy were found during the consolidation process by SPS