王东董春林肖伯律高崇何淼栾国红马宗义
金属学报
doi:10.3724/SP.J.1037.2012.00163
在不同的搅拌头转速及焊接速度下, 对2 mm厚AlCuLi合金进行了搅拌摩擦焊接. 结果表明, 焊核区由细小等轴再结晶晶粒组成. 随搅拌头转速增加, 晶粒尺寸逐渐增加; 随焊接速度增加, 晶粒尺寸略有减小. TEM分析表明, 焊核区的析出相大部分溶解, 在随后的冷却过程中形成粗大的析出相, 而在热影响区析出大量的粗大平衡相. 在较低的焊接速度(80 mm/min)下, 接头在热影响区的硬度最低点发生断裂, 随搅拌头转速增加, 接头强度逐渐升高, 最高可达母材的87%, 延伸率约为10%. 而在较高的焊接速度(200 mm/min)下, 搅拌头转速较低时, 焊核区材料流动不充分, 样品在焊核处发生断裂, 强度较低, SEM分析表明, 断口出现材料流动不充分导致的缺陷; 随搅拌头转速增加, 断口处缺陷明显减少, 对强度影响不显著, 接头强度可达母材的84%.
关键词:
搅拌摩擦焊
,
Al-Li alloy
,
mechanical property
,
microstructure
,
recrystallization
孟亮
,
张宝昌
金属学报
测定了含Ce2090合金-纯Al扩散偶中Cu原子的浓度分布曲线,用Boltzman—Matano法计算了扩散系数.结果表明:微量Ce可使Cu的扩散系数下降Cu的扩散系数与其在扩散偶中浓度分布及浓度梯度有关在合金中添加0.40％Ce与添加0.23％Ce相比,两者降低Cu扩散能力的效果相近
关键词:
扩散
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Al-Li alloy
,
Ce
,
Cu
YAO Daping HU Zhuangqi LI Yiyi ZHANG Yun and SHI Changxu Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
110015
,
China.
材料科学技术（英文）
In this paper,the activation energy for precipi- tate dissolution in binary AI-Li alloy has been in- vestigated by considering precipitate dissolution in Al-Li alloy,continuously heated as a thermally ac- tivated process.The proposed calculation was car- ried out by changing the scanning rate in DSC measurement.The results show that the formation of GP zone is easy because the activation energy for its dissolution is smaller than that for Li atom diffu- sion in the matrix.The δ′dissolution consists of two steps:the first step needs larger thermal activation to break down the superlattice structure,and the second is much easier like GP zone dissolution.The phase is the most stable,which needs much larger thermal activation to disappear.
关键词:
Al-Li alloy
,
null
,
null
,
null
LIU Qing HUANG Xiaoxu YAO Mei YANG Jinfeng Harbin Institute of Technology
,
Harbin
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China Department of Metals and Technology
,
Harbin Institute of Technology
,
Harbin 150006
,
China
金属学报(英文版)
A much higher elongation of a warm rolled superplastic Al-Li-Cu-Mg-Zr alloy was made under two-stage strain rate tests comparing with the single ones.During initial stage of deformation a deformation-induced continuous recrystallization which converted a subgrain structure into a recrystallized grain structure by a continuous increase in boundary misorientations had occurred.The higher the strain rate,the faster the continuous recrystallization and the finer the recrystallized grains.The fine recrystallized grain structure formed during the first stage deformation is the essential condition for the material to have high strain rate hardening and strain hardening during the low second stage superplastic deformation.The combination of strain rate hardening and strain hardening is the reason why the higher elongation may be obtained during two-stage superplastic deformation of the alloy.
关键词:
Al-Li alloy
,
null
,
null
,
null
LIU Yulin ZHANG Yun ZHAO Hong'en HU Zhuangqi SHI Changxu Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
China Associate Professor
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
The solid-liquid interface morphology and solute segregation behaviour of AI-Li alloy 8090 during unidirectional solidification were studied by the liquid metal quenehing method under varied processing conditions.When solidification rate,RO.75 mm/min (temper- ature gradient,G_L=130℃/cm),the structure revealed of planar or dendritic interface respectively.With the increase of R,the interface morphology becomes cellular from planar gradually,within a narrow range.And the greater the R,the,finer the dendrite.Segregation of element Cu and impurity elements Fe and Si are quite severe,the interface morphology markedly influences on solute segregation.During solidification at coarse dendrite interface, their segregation ratios are rather great and solidified structure is coarse.
关键词:
Al-Li alloy
,
null
,
null
,
null
,
null
WANG Zhengfu ZHU Ziyong KE Wei Corrosion Science Laboratory
,
Institute of Corrosion and Protection of Metals
,
Academia Sinica
,
Shenyang
,
ChinaZHANG Yun HU Zhuangqi Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
China
金属学报(英文版)
Studies were made of the influence of aging conditions and applied potentials on the stress corrosion carcking(SCC)susceptibility for an Al-Li-Cu-Mg alloy by slow strain rate technique.The relationship between the relative hydrogen content on specimen surface,the applied potentials and elapsed time has also been examined.The SCC susceptibility was found to be dependent on aging conditions in which the peak aged condition gave the worst SCC resistance and the natural aged condition had the best one. The SCC susceptibility and surface hydrogen content relates to the applied potentials. The anodic potentials increase SCC susceptibility,while the cathodic ones below the critical potential accelerate SCC.It is considered that both the anodic dissolution and
关键词:
Al-Li alloy
,
null
,
null
,
null
CHEN Zheng Northwestern Polytechnical University
,
Xi′an
,
China Lab.No.401
,
Northwestern Polytechnical University
,
Xi′an 710072
金属学报(英文版)
Threshold of fatigue for short through cracks for Al-Li alloy 8090 was evaluated to be lower than that of long cracks,and to decrease with the shortening of the crack length.The correla- tion among the threshold,crack wake,and crack tip shielding of the short fatigue cracks was discussed.The super demarcation length and lowest theoretical threshold of short through fa- tigue cracks were presented.
关键词:
Al-Li alloy
,
null
,
null
,
null
,
null
