Formation and stability of a supersaturated solid solution phase formed during a melt-spinning process

A supersaturated Ni(Hf) solid solution with a Hf concentration up to 5.4% b esides a HfNi5 compound nanophase was shown to have formed in a Hf11Ni89 al loy during melt-spinning. Formation of the supersaturated solubility was di scussed based on a solute trapping model. The composition of the Ni(Hf) pha se was related to the corresponding magnetic property and its evolution upo n the subsequent heating was examined using magnetothermal analysis. The Hf concentration in the Ni(Hf) solid solution phase was found to be significa ntly depleted, and to approach to a lower limit of 1.7% upon isothermal ann ealing treatments while the grain size of the HfNi5 phase remains almost un changed at about 10 nm. (C) 1999 Acta Metallurgica Inc.