(西安建筑科技大學(xué) 冶金工程學(xué)院，西安 710055)
摘 要: 采用普通熔鑄法制備含鐵3%(質(zhì)量分?jǐn)?shù))的鋁鐵二元合金，研究多道次往復(fù)攪拌摩擦加工(Friction stir processing, FSP)對(duì)合金顯微組織的影響。結(jié)果表明：進(jìn)行1~3道次往復(fù)FSP后，各道次加工區(qū)組織不均勻；隨著加工道次的增加，組織均勻細(xì)化程度增大。合金鑄態(tài)組織由α-Al和粗大針狀A(yù)l3Fe相組成，經(jīng)3道次FSP后，攪拌區(qū)組織明顯細(xì)化。原始鑄態(tài)組織轉(zhuǎn)變?yōu)榧?xì)小等軸的再結(jié)晶晶粒，尺寸為2~5 μm，并且部分晶粒中出現(xiàn)層錯(cuò)；粗大的Al3Fe針狀相被破碎成長度小于1 μm的細(xì)小粒狀，彌散分布在鋁基體晶界和晶粒內(nèi)部，細(xì)化的Al3Fe粒子呈現(xiàn)孿晶結(jié)構(gòu)。
關(guān)鍵字: 鋁鐵合金；Al3Fe相；顯微組織；攪拌摩擦加工
（School of Metallurgical Engineering, Xi’ an University of Architecture and Technology, Xi’ an 710055, China）
Abstract:Al-3%Fe (mass fraction) binary alloy was prepared by fusion casting. The effect of reciprocating multi-pass friction stir processing (FSP) on the microstructure of the alloy was studied. The results show that the microstructure of each pass in stir zone is non-uniform after one to three passes reciprocating FSP. With the increase of processing passes, the degree of uniformity and refinement of the microstructure increases. The as-cast alloy is composed of the α-Al and coarse needle Al3Fe phases. The microstructure in stir zone is significantly refined after three passes FSP. The as-cast microstructure in the stir zone is changed into fine equiaxed recrystallized grains with the size of 2−5 μm, and stacking fault appears in some grains. Coarse needle Al3Fe phases are broken into granular phases with the length of less than 1 μm, and disperse in Al matrix grain boundary and grain interior. Refined Al3Fe particles present twin structure.
Key words: Al-Fe alloy; Al3Fe phase; microstructure; friction stir processing (FSP)
