On the practicability of permanent magnets in the system Sm - Fe - Ti: A constitutional argumentation

• Published in: 1992. Digests of Intermag. International Magnetics Conference p. 297
• Main Authors: Reinsch, B., Grieb, B., Henig, E.Th, Petzow, G.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 1992
• Subjects: Grain boundaries; Iron; Permanent magnets; Samarium
• ISBN: 0780306376; 9780780306370
• DOI: 10.1109/INTMAG.1992.696480

Permanent magnets based on the SmFe11Ti (1/12) compound were considered to compete with Nd2Fe14B based magnets. However, maximum coercivity values reached so far by mechanical alloying or rapid quenching were rather disappointing (≈ 5 kOe). On the other hand, extremely high coercivity values at a low remanence were found in mechanically alloyed Sm-rich samples based on the hexagonal Sm5(Fe,Ti)17 (5/17) compound. As coercivity strongly depends on the microstructure of a magnet, detailed knowledge of the phase relations is indispensable. The yet published papers dealing with this question disagree in several points, and in both the 5/17 compound was not confirmed to exist. Therefore, comprehensive constitutional investigations based on microstructural examinations, X-ray diffraction, EDX and thermal analyses were carried out to clear up the points at issue of the phase diagram and to clarify the question, whether or not magnets in this system could become feasible.