Regensburg 1998 – wissenschaftliches Programm

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M: Metallphysik

M 25: Postersitzung, gemeinsam mit AM,DS,DF,TT,SY B

M 25.24: Poster

Donnerstag, 26. März 1998, 15:10–19:10, A (Sammelgeb"aude)

extraction of boron from Fe-Si-B and Fe-Co-Si-B amorphous ribbons. — •g. david, s. roth, j. eckert, and l. schultz — ifw dresden, institut for metallic materials

Crystalline TM alloys are brittle and cannot be cold rolled, furthermore they may have a large melting point and may, therefore, be difficult to process by RS-technology. Such alloys are often more easly processable by RS-technology if some boron, carbon or phosphorus is added. It is well known, that small amounts of carbon can be extracted by annealing in wet hydrogen. It is demonstrated here, that rather large amounts of boron may be extracted, too, using a proper two-steps annealing treatment in wet and dry hydrogen. We suppose that boron escapes as boric acid. So, hydrogen as well as oxygen have to be supplied during annealing. Fe-Si-B and Fe-Co-Si-B of different compositions were rapidly quenched to ribbons about 10 mm wide and 20-25 m thick. Using a proper two-steps annealing treatment in wet and dry hydrogen, the ribbons are composed of single-phased Fe-Si or Fe-Co-Si solid solution with the boron being extracted completely The annealing treatment effect on the amorphous ribbons was investigated by XRD, SEM and TEM measurements. Soft magnetic properties will be discused as a function of composition and annealing parameters.