变形工艺对01420Al-Li合金板材晶粒细化的影响  

Effects of deformation process on grain refinement of the 01420 Al-Li alloy plate

作　　者：罗智辉 叶凌英[2] 严明[1] 

机构地区：[1]湖南工程学院,湖南湘潭411104 [2]中南大学材料科学与工程学院湖南长沙410083

出　　处：《轻合金加工技术》2013年第11期29-34,共6页Light Alloy Fabrication Technology

基　　金：湖南省教育厅科研项目(10C0553)

摘　　要：采用机械热处理法(TMP)制备01420Al-Li合金细晶板材,研究包铝、预热温度、中间退火温度及转向轧制对轧制开裂及晶粒细化的影响。结果表明,板材包铝后轧制开裂得到明显抑制,但再结晶后晶粒尺寸较大;板材在低温(低于350℃)轧制时开裂严重,将轧制温度提高到400℃,并在400℃中间退火2 h可获得无轧制开裂的板材,但经再结晶退火后的晶粒组织粗大,粒径约为16μm;降低中间退火温度并采用转向轧制,板材轧制不开裂,而且细化晶粒及明显减小板材厚度方向层状分布的程度,再结晶后板材表面层的晶粒细小等轴,平均晶粒粒径为10μm;中心层晶粒组织相对粗大、略成扁平状,平均晶粒粒径为13μm,该中心层约占板材厚度的20%。Fine grained 01420 Al-Li alloy sheets were produced by thermo-mechanical process （TMP）. The effects of aluminum coating, preheating temperatures, intermediate annealing temperatures and cross-rolling on rolling cracks and grain refinement were investigated. The results show that aluminum coating can restrain rolling cracks,but lead to coarse recrystallization grains; low temperature rolling （lower than 350℃ ） usually leads to severe sheet crack. Non-fractured sheets can be obtained by rolling at 400℃and intermediate annealing 2 h at 400℃ ,which results in a coarse grain structure with the grain size of about 16 μm after recrystallization. Intermediate annealing at lower temperatures gives rise to finer grains, but if an unidirectional rolling is applied after annealing, cracks occur when the roll- ing reduction is too large. However, direction-changing rolling after annealing not only eliminates the cracks during deformation but also enhances grain refinement and decreases layer grain structure through the thickness. The surface layer contains fine equiaxed grains of about 10 μm whereas central layer contains coarse elongated grains of about 13 μm which accounts for about 20% of the whole thickness.

关 键 词：机械热处理 01420Al-Li合金 转向轧制 中间退火 晶粒细化 

分 类 号：TG339[金属学及工艺—金属压力加工]