| Dispersion strengthened Al-Ti alloys with very fine microstructures were fabricated by double mechanical alloying (DMA) process, and the elevated temperature mechanical properties of these alloys were investigated. The alloys prepared by DMA process represented better distribution and smaller size of precipitates than those by single mechanical alloying(SMA) process. The analysis of XRD and TEM observation indicated that the size of Al₃Ti phase was smaller than 30 ㎚. The lattice parameter of Al was decreased from 4.0485 to 4.0401Å during MA, which indicates the dissolving of Ti into Al matrix. In this study, the maximum solid solubility of Ti during MA was estimated to be 8.82 wt%. Inspite of effective dispersion of intermetallic compound by DMA process, the alloys did not show improved mechanical properties as expected, due to too high volume percentage of intermetallic dispersoids. |
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