(1. 廣東省工業(yè)分析檢測中心，廣州 510650；
2. Australian Centre for Microscopy & Microanalysis, The University of Sydney, Sydney 2006 Australia)
摘 要: 應(yīng)用高分辨透射電鏡觀察了5083鋁合金軋制退火組織中彌散相的形態(tài)和微觀結(jié)構(gòu)。結(jié)果表明：呈球狀或不規(guī)則形狀、尺寸約200~300 nm的彌散相為θ-Al45(Mn,Cr)7相，屬單斜結(jié)構(gòu)，晶胞大小a=2.5196 nm，b=0.7574 nm，c=1.0949 nm，β=128.72°。另外，還發(fā)現(xiàn)該相顆粒內(nèi)部易產(chǎn)生孿晶、孿晶疇和復(fù)合孿晶，伴有二次孿晶(或微孿晶)和反相疇界等晶體缺陷，孿晶面分別為 或 ，共軛面為 或 。同時從晶體學(xué)角度解釋了該相孿晶和復(fù)合孿晶等缺陷的生成機(jī)制。
關(guān)鍵字: 5083鋁合金；透射電鏡；θ-Al45(Mn,Cr)7相；孿晶
（1. Guangdong Industrial Analysis and Testing Center, Guangzhou 510650, China;
2. Australian Centre for Microscopy & Microanalysis, The University of Sydney, Sydney 2006, Australia）
Abstract:The morphology and microstructure of dispersoids in 5083 alloy with H116 temper condition were investigated using JEOL 2100F transmission electron microscope equipped with EDS and STEM. The results show that the discrete spherical-like or irregular-shaped θ-Al45(Mn,Cr)7 phase which has monoclinic structure with a unit cell of a=2.5196 nm, b=0.7574 nm, c=1.0949 nm, β=128.72° is observed in 5083 alloy. One type of twin is shown to be a or twin with the or plane serving as the twinning plane, and another type of orientation twin is seen to be a domain with the plane serving as the coherent plane. The boundaries of both domain and twin are found to be coincident with the twinning plane. In addition composite-twins are also observed in θ-Al45(Mn,Cr)7 particles. Possible formation mechanisms of the twins are discussed based on a crystallographic consideration.
Key words: 5083 aluminium alloy; TEM; θ-Al45(Mn,Cr)7 phase; twin
