Containerless Melting and Solidification Process of Nd85Fe15 and Nd90Fe10 Alloys during Electromagnetic Levitation Apparatus under Microgravity Condition by Parabolic Flight and the Effect of Microgravity Condition on the Ferromagnetic Metastable Phase Crystallizationt

Abstract

Containerless solidification experiments of NdasFe1s and Nd 90Fe10 alloys during parabolic flights were carried out using an electromagnetic levitation furnace with 1 kW power supply. The tempera­ture of the sample during melting and solidification processes was precisely measured with an optical pyrometer. The forced cooling by helium gas was also tried to attain the lager cooling rate of the sample. The same ferromagnetic metastable phase as that obtained by levitation experiments under gravity condition was obtained. The cooling rate for the formation of the metastable phase under microgravity was small and about one seventh of that under gravity condition. The results showed the microgravity condition was effective for the metastable phase formation of hard magnetic materi­als.