High-pressure sintering and magnetic properties of Fe86Zr11-xNbxB3(x=5.5, 6) amorphous alloys
(1. School of Materials Science and Engineering, Central South University,
Changsha 410083, China;
2. Institute of Materials Science and Engineering, Tongji University,
Shanghai 200092, China;
3. Shanghai Institute of Ceramics, Chinese Academy of Sciences,
Shanghai 200050, China)
Changsha 410083, China;
2. Institute of Materials Science and Engineering, Tongji University,
Shanghai 200092, China;
3. Shanghai Institute of Ceramics, Chinese Academy of Sciences,
Shanghai 200050, China)
Abstract: The thermal stability of milling Fe86Zr11-xNbxB3(x=5.5, 6) melt-spun strip powders and the influence of high-pressure sintering conditions on phase component and grain size of bulk alloys were investigated by X-ray diffractometry(XRD), differential scanning calorimetry(DSC) and scanning electron microscopy(SEM). The results show that milling melt-spun powder remains in the amorphous state, and the crystallization temperature of which is 480-530℃, the apparent activation energy Ep of crystallization process is 294.1-219.5kJ/mol. The increasing Nb content can increase crystallization temperature and decrease Ep. Under the sintering conditions of 5.5GPa/3min, when Pw is 1150W, single phase α-Fe nanocrystalline (20.6-26.7nm) bulk alloy with relative density higher than 99.0% can be obtained. Under the sintering conditions of 5.5GPa/1150W/3min, the magnetic properties of these nanocrystalline bulk alloys are Fe86Zr5.5Nb5.5B3 alloy, Bs=1.15T, Hc=5.08kA•m-1; Fe86Zr5Nb6B3 alloy, Bs=1.26T, Hc=4.27kA•m-1.
Key words: Fe-based alloy; amorphous alloy; thermal stability; high-pressure sintering; bulk alloy; nanocrystalline; magnetic properties