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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