(哈爾濱工業(yè)大學(xué) 現(xiàn)代焊接生產(chǎn)技術(shù)國(guó)家重點(diǎn)實(shí)驗(yàn)室，
哈爾濱 150001)
摘 要: 采用攪拌摩擦焊方法對(duì)2mm厚的Al-Cu-Li合金軋制板進(jìn)行了焊接。 接頭內(nèi)形成了焊核區(qū)、 熱機(jī)影響區(qū)和熱影響區(qū)。 焊核區(qū)由細(xì)等軸再結(jié)晶組織構(gòu)成； 熱機(jī)影響區(qū)內(nèi)的組織發(fā)生較大的彎曲變形， 并在熱循環(huán)的作用下發(fā)生了回復(fù)反應(yīng)； 熱影響區(qū)形成了粗大的板條狀組織。 實(shí)驗(yàn)結(jié)果表明： 在200mm/min的焊接速度下， 接頭的拉伸強(qiáng)度最高， 達(dá)到393MPa， 斷裂形式為韌性和脆性的混合型斷裂； 在500mm/min的焊接速度下， 接頭強(qiáng)度為267.7MPa， 斷裂形式為脆性斷裂。
關(guān)鍵字: 攪拌摩擦焊； Al-Cu-Li合金； 接頭組織； 力學(xué)性能
（State Key Laboratory of Advanced Welding Production Technology, Harbin Institute of Technology, Harbin 150001, China）
Abstract: Friction-stir welds of Al-Cu-Li aluminum rolled sheet material in 2mm thickness were completed and the joint microstructures could be divided into there regions, namely, welded nugget zone(WNZ), thermal-mechanically affected zone(TMAZ) and heat affected zone(HAZ). And there are much difference for microstructures among the above three zones: the microstructures within the WNZ, in which dynamic recrystallization occurred, consist of refined, equiaxed grains; those within the TMAZ, in which recovery occurred, consist of highly deformed grains; those within the HAZ consist of coarse lath grains. Mechanical property measurement and fracture analysis demonstrate that the peak tensile strength of the joint is 393MPa at 200mm/min and the fracture mode is ductile/brittle mixed fracture; and at 500mm/min, tensile strength of the joint is 267.7MPa, and the fracture mode is brittle fracture.
Key words: friction-stir welding; Al-Cu-Li alloy; joint microstructures; mechanical property
