STP1366: Effect of Ion-Irradiation on Phase Transformation in TiNi Shape Memory Alloys

    Matsukawa, Y
    Graduate Students, Associate Professor and Professor, Hokkaido University, Sapporo,

    Sumita, Y
    Graduate Students, Associate Professor and Professor, Hokkaido University, Sapporo,

    Ohnuki, S
    Graduate Students, Associate Professor and Professor, Hokkaido University, Sapporo,

    Watanabe, S
    Graduate Students, Associate Professor and Professor, Hokkaido University, Sapporo,

    Namba, C
    Associate Professor, National Institute for Fusion Science, Toki,

    Takahashi, H
    Professor, Center for Advanced Research of Energy Technology, Hokkaido University, Sapporo,

    Pages: 12    Published: Jan 2000


    Abstract

    Ion-irradiation induced amorphization and crystallization processes in TiNi shape memory alloys have been investigated. The primary concern is to clarify the relationship between the critical temperature for irradiation-induced amorphization and the thermal crystallization temperature. The critical temperature for irradiation-induced amorphization was 673K, however, the edge of the foil specimen crystallized during the irradiation at a lower temperature. The crystallization temperature of the specimen edge during irradiation decreased with increasing of incident ion energy. Thermal annealing experiments revealed that the thermal crystallization preferentially occurred at the specimen edge and the crystalline-amorphous (C-A) interface; The crystallization temperature of the preferential sites were 573K and 623K, respectively. These preferential nucleation indicate that the nucleation barrier dominates the thermal crystallization temperature; the critical temperature for amorphization is higher than the thermal crystallization temperature with no nucleation barrier.

    Keywords:

    inter-metallic compounds, shape memory alloy, ion-irradiation, amorphization, crystallization


    Paper ID: STP12460S

    Committee/Subcommittee: E10.08

    DOI: 10.1520/STP12460S


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