Formation of NiAl2O4 by Solid State Reaction |
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| Authors: | F S PETTIT E H RANDKLEV E J FELTEN |
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| Affiliation: | Pratt &Whitney Aircraft, Division of United Aircraft Corporation, North Haven, Connecticut 06473 |
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| Abstract: | The growth of nickel-aluminum spinel, NiAl2O4, in diffusion couples of polycrystalline Al2O3 and NiO was investigated between 1200° and 1500°C. The growth kinetics for the spinel layer obeyed a parabolic rate law in this temperature range. Marker experiments showed that the spinel layer formed by counterdiffusion of nickel and aluminum ions. Comparison of experimental and theoretical values of the parabolic rate constants suggests that the diffusion of aluminum ions through the spinel layer is rate controlling. |
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