FeNbYB非晶合金的晶化过程及磁性能

Crystallization processes and magnetic properties of FeNbYB amorphous alloys

用单辊快淬法制备Fe74Nb6-xYxB20(x=3 at%、4 at%、5 at%)非晶合金,取不同的温度对合金热处理,利用差热分析仪(DTA)、X射线衍射仪(XRD)、透射电子显微镜(TEM)、振动样品磁强计(VSM)研究了合金的非晶形成能力、晶化过程和磁性能。结果表明,添加微量Y元素提高了合金的非晶形成能力,当Y含量为5 at%时,Fe74Nb1Y5B20非晶合金过冷液相区具有最大值、△Tx=63℃。Fe74Nb6-xYxB20(3 at%、4 at%、5 at%)合金的晶化过程为:非晶→非晶+α-Fe+Fe23B6+Fe2B→α-Fe+Fe23B6+Fe2B。随着退火温度的升高,3种合金Fe74Nb6-xYxB20(x=3 at%、4 at%、5 at%)饱和磁化强度MS变化趋势是一致的,在670℃退火后3种合金MS均达到最大、分别为128、122、134 A·m2·kg-1,矫顽力Hc为2.96、3.12、3.36 kA·m-1,在750℃退火后,Hc快速增大。

Fe74Nb6-xYxB20(x = 3 at%,4 at%,5 at%) amorphous alloys were prepared by melt-spinning technique and annealed at different temperatures.The glass forming ability,crystallization process and magnetic property of the Fe74Nb6-xYxB20 amorphous alloys were studied by differential thermal analysis(DTA),X-ray diffraction(XRD),transmission electron microscopy(TEM) and vibrating sample magnetometer(VSM).The results show that minor Y addition enhances the glass forming ability of the alloys.The supercooled liquid region of Fe74Nb1Y5B20 amorphous alloy reaches the maximum value(△Tx= 63 ℃).The crystallization processes of the Fe74Nb6-xYxB20(x = 3 at%,4 at%,5 at%) amorphous alloys are similar on the whole,which is as follows:amorphous→ residual amorphous + α-Fe + Fe23B6+ Fe2 B → α-Fe + Fe23B6+ Fe2 B.The changing trends of saturation magnetization(MS) of the Fe74Nb6-xYxB20(x =3 at%,4 at%,5 at%) alloys are the same with increasing annealing temperature.The saturation magnetization(MS) and the coercive force(Hc) of the Fe74Nb6-xYxB20(x = 3 at%,4 at%,5 at%) alloys annealed at 670 ℃ are 122,128,134 A·m2·kg-1and 2.96,3.12,3.36 kA·m-1,respectively.Abruptly deterioration of the coercive force(Hc) of Fe74Nb6-xYxB20(x =3 at%,4 at%,5 at%) alloys annealed at 750 ℃ are observed.