| Abstract |
| The cold rolled Al-0.2 wt% Sc alloy sheets were pre- heat treated: (1) as solution treated at 630℃ for 1 hour and (2) as artificial aged at 300℃ for 5 hours, and the following accumulative roll bonding was conducted up to the 8 cycles at ambient temperature. The interconnecting boundary spacing of the aged alloys was narrow and maintained constantly at each ARB cycle. While, the spacing of solution treated alloy was relatively broad and decreased rapidly with increasing ARB cycles. The fraction of high angle boundaries in both alloys increased gradually with increasing equivalent strain, however the age-ARB alloys showed relatively higher fraction of HAGBs than the solution treat-ARB alloys at the same strain levels. And the former shows faster development of lamellar structure than the later. These variations are attributed to the fact that the nano-scale, semi-coherent A13Sc hinders the migration of dislocation. However, those precipitates cannot apply pinning effect sufficiently during static recrystallization above 350℃ because the driving pressure for recrystallization overcomes the Zener pinning pressure. (Received September 30, 2004) |
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| Key Words |
| Al3Sc, Accumulative roll bonding, High angle boundary, Lamellar structure, Dynamic recovery, Abnormal grain growth |
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