| Effect of aging condition on the microstructure and hardness properties of Al-3Li, Al-3L₁-2Cu, Al-3Li-2Cu-0.3Zr have bean studied. The alloy ribbons have been prepared by means of Single Roll Melt Spinning by rapid solidification technique. In rapidly solidified Al-3Li-2Cu, Al-3Li-2Cu-0.3Zr alloy ribbons show the icosahedral intermetallic compound of five-fold symmetry which is placed in cell-boundary and matrix. In the matrix precipitated fine δ(Al₃Li) phase. Heat-treated at 250 ℃ 1hr. In this condition, δ`(Al₃Li) phase started decompose. The icosahedral intermetallic compound has been grown. When heat-treated at 300 ℃ 1hr, the δ(Al₃Li) phase has been decomposed all. In the matrix, icosahedral intermetallic compound has been grown greatly. The micro-hardness has been obtained in more high Al-Li-Cu-(Zr) alloy than Al-Li alloy. Strength-hardened phenomena showed solution hardening by the addition of Cu. When the heat-treated at 250 ℃ 1hr, in the alloy of Zr addition, delayed decomposed δ` phase. In the case, micro-hardness gradually decreased. When the heat-treatment have done at 300 ℃ 1hr, the micro-hardness has been decreased because δ` phase decomposed all. |
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