Thermal expansion of Fe-TM-B ( TM = transition metal) bulk amorphous forming alloys

In order to clarify the potential of bulk amorphous alloys as a new class of structural materials with high dimensional stability, the thermal expansion and magnetic properties of amorphous Fe 56 Co 7 Ni 7 Zr 10 B 20 doped with Cr have been investigated. Both the magnetic moment and the Curie point of amorphous Fe 56 Co 7 Ni 7 Zr 10 B 20 were suppressed by Cr addition. The effect of Cr on the magnetic moment was well described by assuming a reduction of 4 μ B ∕ Cr atom. It was found that the Curie temperature can be controlled by Cr content over a wide range of 200 K in the vicinity of room temperature. Although Invar characteristics were absent from the thermal expansion curves, amorphous Fe 56 Co 7 Ni 7 Zr 10 B 20 doped with 1 at. % Cr was found to exhibit a small coefficient of thermal expansion comparable to Kovar alloys, indicating that bulk amorphous alloys may have a potential for commercial low expansion materials.