Effect of Cu Addition on Thermal Stability and Crystallization Process of FeCoZrB Amorphous Alloy

Fe41.5Co41.5Zr7B9Cu1 and Fe38.5Co38.5Zr7B5Cu1 amorphous alloys were prepared by adding lat% Cu based on Fe42Co42Zr7B9 with low B content and Fe39Co39Zr7B15 alloy with high B content. Crystallization curves and structure of crystalline phase of the alloys were tested by synchronous thermal analyzer (STA), X-ray diffraction (XRD) and transmission electron microscope (TEM). The effects of Cu addition on the thermal stability and crystallization process of Fe42Co42Zr7B9 and Fe39Co39Zr7B15 amorphous alloys were investigated. The results show that the addition of Cu slightly improves the thermal stability of Fe42Co42Zr7B9 amorphous alloy, and significantly improves the thermal stability of Fe39Co39Zr7B15 amorphous alloy. For Fe42Co42Zr7B9 and Fe39Co39Zr7B15 amorphous alloys, there is obvious peak shift at the initial stage of crystallization. For Fe41.5Co41.5Zr7B9Cu1 and Fe38.5Co38.5Zr7Bi5Cu1 alloys, there is almost no peak shift during the crystallization process. TEM results show that the addition of Cu improves the distribution uniformity of nanocrystals and slightly increases the grain size. The effect of Cu addition on the thermal stability and crystallization process of Fe39Co39Zr7B15 alloy with high B content is greater than that of Fe42Co42Zr7B9 alloy with low B content.