YAO Daping HU Zhuangqi LI Yiyi ZHANG Yun SHI Changxu Institute of Metal Resarch
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Shenyang
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China Institute of Metal Research
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Academia Sinica
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Shenyang 110015
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China
金属学报(英文版)
The aging precipitation structure and the properties of Al-Li-Cu-Zr alloys with 3 different Cu/Li ratios have been studied.Experimental results show that the aging hardening of the alloys consists of two steps:The first is strengthened by δ′-phase(δ′+T_1 phase in alloy No.3),and the second by δ′+T_1 phase(δ′+T_1+θ′phase in alloy No.3).The plate of T_1-phase can absorb the Li atoms from δ′ particles when the plate bumped into δ′-phase,and therefore, these δ′ phase particles become smaller and gradually disappear.The strength and hardness increase with the increase of Cu/Li ratio and cuases a decrease in plasticity.The crack mode would change from transgranular to intergranular.This is due to the precipitation of the equi- librium phases contained Cu at grain boundaries.
关键词:
A1-Li alloy
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ZHANG Yun ZHAO Hong'en YAO Daping GAO Guozhong CHEN Jizhi HU Zhuangqi Institute of Metal Research
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Academia Sinica
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Shenyang
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China[Originally published in ACTA METALL SIN(CHINESE EDN)25(3)1989 pp A161—A167. Associate Professor
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Institute of Metal Research
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Academia Sinica
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Shenyang
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110015
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China
金属学报(英文版)
The relationship among the microstructures,properties and the phase transformation in Al-2.2Li-2.5Cu-0.2Mg alloy after various treatments have been studied by optical microscopy and TEM observations.It is verified that solution treated at 525℃ for 1h is saris- factory for this alloy in which all the alloying elements are dissolved in the α-Al matrix,and aging at 190℃ for 16 h is the peak-aged condition.The alloy subjected to treatment is strengthened only be T_1 phase.In overaged or underaged conditions,the alloy is strengthened by two phases,in this cases,the strengthening effect is smaller than that by one phase.The deformation prior to aging would develop the plasticity and do not decrease the strength of the experimental alloy.
关键词:
A1-Li alloy
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