| Raipidly solidified Al-Ti-Si and Al-Ti-Si-Cr base alloys were prepared by melt spinning process. The effects of solute on the microstructural change and age hardening after heat treatment have been studied to improve the high temperature properties in the Al alloys. In the supersaturated Al-Ti-Si alloy, age hardening occurred after lhr aging in the range of 400℃∼500℃, which seems to be attributed to the precipitation of metastable L1₂-(Al, Si)₃Ti phase. And the addition of Cr to Al-Ti-Si alloy system affected the precipitate morphology by forming (Al, Si)₃Ti containing Cr to stabilize the microstrucure at elevated temperature. As a result, it is found that there is a strong correlation between the microstructure and the precipitation hardening for the aged alloys. |
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