Effect of the Decomposition of the Supersaturated beta Solid Solution in Melt-Quenched Ni_(65)Al_(35) and Ni_(56)Al_(34)Co_(10) Alloys on the Reversibility of the Martensitic Transformation

摘要

Melt-quenched Ni_(65)Al_(35) and Ni_(56)Co_(10)Al_(34) (at percent) alloys are studied by electrical resistance measurement and electron microscopy. The effects of the isothermal holding time in the supersaturated beta solid solution field and the heating rate during thermal cycling on the restoration of the reversibility of the martensitic transformation are investigated. After short-term aging in the B2 austenite field followed by long-term aging in the L1_0 martensite field, the melt-quenched Ni_(65)Al_(35) and Ni_(56)Co_(10)Al_(34) alloys retain their high thermal stability of the reversibility of the martensitic transformation.