机械工程学报
機械工程學報
궤계공정학보
CHINESE JOURNAL OF MECHANICAL ENGINEERING
2009年
7期
108-113
,共6页
高强铝合金%冲击韧性%热影响区%微观组织
高彊鋁閤金%遲擊韌性%熱影響區%微觀組織
고강려합금%충격인성%열영향구%미관조직
High strength aluminum alloy Impact toughness Heat affected zone Microstructure
以2519-T87高强铝合金为研究对象,研究其接头的冲击断裂性能及微观组织.研究表明,晶界上分布的α+θ(CuAl<,2>)共晶相是焊缝中心和熔合线附近区域韧性较差的主要原因,并且由于熔合线附近等轴晶区中的共晶相数量高于焊缝中心区域,导致其成为接头韧性最差的区域.晶界液化以及显微裂纹的产生是部分熔化区脆化的主要原因.析出物的溶解使完全回归区获得接头最大冲击吸收功22 J,而析出物的粗化导致过时效区韧性降低,冲击吸收功仅仅只有7 J.断口观察发现除了部分熔化区的断口是脆性断口,接头其他区域断口均为韧窝型断口,且完全回归区中的韧窝最深,韧窝内部的析出物最少.
以2519-T87高彊鋁閤金為研究對象,研究其接頭的遲擊斷裂性能及微觀組織.研究錶明,晶界上分佈的α+θ(CuAl<,2>)共晶相是銲縫中心和鎔閤線附近區域韌性較差的主要原因,併且由于鎔閤線附近等軸晶區中的共晶相數量高于銲縫中心區域,導緻其成為接頭韌性最差的區域.晶界液化以及顯微裂紋的產生是部分鎔化區脆化的主要原因.析齣物的溶解使完全迴歸區穫得接頭最大遲擊吸收功22 J,而析齣物的粗化導緻過時效區韌性降低,遲擊吸收功僅僅隻有7 J.斷口觀察髮現除瞭部分鎔化區的斷口是脆性斷口,接頭其他區域斷口均為韌窩型斷口,且完全迴歸區中的韌窩最深,韌窩內部的析齣物最少.
이2519-T87고강려합금위연구대상,연구기접두적충격단렬성능급미관조직.연구표명,정계상분포적α+θ(CuAl<,2>)공정상시한봉중심화용합선부근구역인성교차적주요원인,병차유우용합선부근등축정구중적공정상수량고우한봉중심구역,도치기성위접두인성최차적구역.정계액화이급현미렬문적산생시부분용화구취화적주요원인.석출물적용해사완전회귀구획득접두최대충격흡수공22 J,이석출물적조화도치과시효구인성강저,충격흡수공부부지유7 J.단구관찰발현제료부분용화구적단구시취성단구,접두기타구역단구균위인와형단구,차완전회귀구중적인와최심,인와내부적석출물최소.
The 2519-T87 high strength aluminum alloy is welded to study the impact properties and microstrueture of the joints. Results indicate that the lower impact toughness of weld centre zone and fusion line zone is caused by the network distribution of α+θ (CuAl<,2>) euteetic phase along the grain boundary. And the higher amount of euteetic phase is in the equiaxed zone along fusion line, which makes it have the poorest impact toughness. The local melting and microfissure are the main cause for the embrittlement of partially melted zone. The value of the impact absorbed energy in the full-reverted region reaches the maximum 22 J because of the dissolution of precipitates, whereas that value in overaged zone is only 7 J because of coarsening of precipitates. Fractography shows that the fracture of partially melted zone is brittle intergranular fracture, and those of other zones are dimple fractures. The dimples in the fracture of the fully reverted zone are the deepest, and there are least particles in them.