(1. 安陽工學(xué)院 機(jī)械工程學(xué)院，安陽 455000；
2. 河南理工大學(xué) 材料科學(xué)與工程學(xué)院，焦作 454000；
3. 安陽工學(xué)院 安陽市先進(jìn)航空材料與加工技術(shù)重點實驗室，安陽 455000)
摘 要: 采用電子背散射衍射(EBSD)研究了1060鋁/AZ31B鎂異種金屬攪拌摩擦焊(FSW)接頭的晶粒組織、織構(gòu)演化和力學(xué)性能。結(jié)果表明：接頭組織中從熱影響區(qū)(HAZ)至焊核區(qū)(NZ)，低角度晶界(LAGBs)百分比和平均晶粒粒徑均逐漸減少。在HAZ，晶粒組織與母材相似，熱機(jī)械影響區(qū)(TMAZ)則發(fā)生了動態(tài)再結(jié)晶，形成了粗晶粒和細(xì)小等軸晶粒共存的顯微組織，而NZ由均勻細(xì)小的等軸晶組成。HAZ織構(gòu)與母材相似，鋁側(cè)NZ形成了{(lán)001}〈100〉再結(jié)晶立方織構(gòu)，在NZ中心，鎂晶粒取向從〈0001〉||ND向〈0001〉||WD偏轉(zhuǎn)，而在鎂側(cè)NZ，晶粒的取向為〈0001〉||TD。接頭的抗拉強(qiáng)度為96.1 MPa，伸長率為13.2%，分別達(dá)到1060鋁合金母材抗拉強(qiáng)度的95%和伸長率的65%。鋁側(cè)HAZ位錯密度減小導(dǎo)致的材料軟化以及鋁側(cè)HAZ與TMAZ之間晶粒粒徑的差異促使接頭從鋁側(cè)HAZ/TMAZ界面附近斷裂。
關(guān)鍵字: 鋁/鎂異種金屬攪拌摩擦焊；晶粒組織；織構(gòu)演化；力學(xué)性能；斷裂機(jī)理
（1. School of Mechanical Engineering, Anyang Institute of Technology, Anyang 455000, China;
2. School of Materials Science and Engineering, Henan Polytechnic University, Jiaozuo 454000, China;
3. Anyang Key Laboratory of Advanced Aeronautical Materials and Processing Technology, Anyang Institute of Technology, Anyang 455000, China）
Abstract:The grain structure, texture evolution and mechanical properties of friction stir welded dissimilar metal joints of 1060 aluminum and AZ31B magnesium alloys were studied by electron backscatter diffraction (EBSD). The results show that the proportion of low angle grain boundaries (LAGBs) and average grain size decrease gradually from heat affected zone (HAZ) to nugget zone (NZ). In HAZ, the grain structure is similar to that of the base metals, while dynamic recrystallization occurs in the thermo-mechanical affected zone (TMAZ), forming a microstructure in which coarse grains and fine equiaxed grains coexist. NZ is composed of uniform and fine equiaxed grains. The texture of HAZ is similar to that of base metals. The {001}〈100〉 recrystallized cubic texture is formed in the Al-side NZ. At the NZ center, the grain orientation of magnesium grains deflects from the 〈0001〉|| normal direction (ND) to 〈0001〉|| welding direction (WD), while at the Mg-side NZ, the orientation of grains is 〈0001〉|| transverse direction (TD). The tensile strength of the joint is 96.1 MPa and the elongation is 13.2%, reaching 95% of the tensile strength and 65% of the elongation of 1060 aluminum alloy base metal respectively. The material softening caused by the decrease of HAZ dislocation density on the aluminum side and the difference of grain size between HAZ and TMAZ on the Al-side jointly promote the fracture of the joint near the Al-side HAZ/TMAZ interface.
Key words: Al/Mg dissimilar metal friction stir welding; grain structure; texture evolution; mechanical property; fracture mechanism
