| In order to investigate the effect of Ce on the thermal stability of Al Ti alloy, Al- 8wt.%(Ti+Ce) powders with different Ti to Ce atomic ratio were mechanically alloyed in an attritor. The steady state was obtained after 16 hours milling for all the alloys. The mechanically alloyed powders were vacuum hot pressed and isothermally aged for 100 hours at 400 550℃. The coarsening of A1- Ti intermetallic compounds was retarded by addition of Ce and the thermal stability was improved. The lattice parameter variations of Al-Ti-Ce intermetallic compounds were measured, and the addition of Ce increased the overall lattice mismatch between the intermetallic compound and Al matrix, and so the interfacial energy. Therefore, when considered the solubility and diffusivity of Ce in Al, it was considered that the low solid solubility of Ce in Al matrix was the major factor to the increased thermal stability of Al-Ti alloy. |
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