Thermal Stability of Microstrucuture and Microhardness in Nanostructured Ni-Cr Alloy Foils Prepared by RF Sputtering Method(Materials, Metallurgy & Weldability)
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Nanostructured Ni-Cr binary alloy foils were fabricated by utilizing the RF-magnetron sputtering method and characterization of the foils was performed to examine microstructure, mechanical properties and thermal stability. Each foil was a nanostructured solid solution with an average grain size less than 60nm. Average grain size increased with an increase in Cr content up to 40at%. The microhardness of the foils increased with the solute content up to 5at% and showed the maximum value of 7.0GPa, but then decreased for the further increase of Cr content. The Ni-15at%Cr alloy foil showed no decrease of microhardness up to 773K during isochronal annealing for 7.2ks, but a drastic decrease occurred as the annealing temperature was raised above 773K and the hardness decreased to 2.5GPa at 923K. Abnormal grain growth was observed in the Ni-15at%Cr alloy during isothermal annealing at 973K. The decrease of the microhardness was due to the grain growth during the annealing.
- Transactions of JWRI
Transactions of JWRI 31 (1), 25-32, 2002-09