Abstract ▼ AI-Helper

The texture and thermomechaincal properties of nanocrystalline Ni and Invar alloy foil fabricated by using an electroforming method were investigated. The average crystalline sizes of the materials were calculated to range between 5 and 20 nanometers. The as-deposited texture was characterized by a ...

The texture and thermomechaincal properties of nanocrystalline Ni and Invar alloy foil fabricated by using an electroforming method were investigated. The average crystalline sizes of the materials were calculated to range between 5 and 20 nanometers. The as-deposited texture was characterized by a strong //ND fibre and a weak //ND fibre. Nanocrystalline Ni and Invar alloy foil reveal superior mechanical properties to the conventional Ni and Invar alloy due to the nanostructures. Especially, it is striking that nanocrystalline Invar alloy holds minus coefficients of thermal expansion in a certain temperature range. Grain growth occurred when the Ni foil was annealed at above 260℃, and so was the Invar foil at above 375℃. It is noted that in the early stages of annealing, abnormal grain growth occurred with rapid growth of //ND grains. in both the samples, the texture evolution following the grain growth was chareacterized as strongly developed //ND fibre components at the expense of the //ND fibre components. This texture change was interpreted and discussed in terms of orientation dependence of energy density.

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