钇对Nd-Fe-Al-Ni非晶合金热稳定性与晶化行为的影响

Effect of Yttrium on Thermal Stability and Crystallization Behavior of Nd_(60)Fe_(20)Al_(10)Ni_(10) Amorphous Alloys

采用差示扫描量热法(DSC)、X射线衍射(XRD)和透射电镜(TEM)研究了Y对Nd-Fe-Al-Ni非晶合金热稳定性和晶化行为的影响。结果表明,淬火态的Nd60Fe20Al10Ni10-xYx(x=0,2)合金基本为非晶组织同时还含有少量的淬态相,Y的加入抑制了淬态相的析出。加入Y后,非晶合金的晶化开始温度和晶化峰值温度都向高温方向移动,证明其热稳定性提高。Y的加入改变了合金的晶化方式和最终晶化产物,使非晶基体中析出的晶化相更加弥散圆整细小。并且Y具有在化学上钝化氧杂质的作用,从而抑制了氧的有害作用。利用Kissinger方程获得了Nd60Fe20Al10Ni8Y2非晶合金的晶化开始和晶化峰值激活能分别为1.21和1.16 eV。

The effect of Y on the thermal stability and the crystallization behavior of Nd-Fe-Al-Ni amorphous alloys was investigated using X-ray diffraction （XRD）, differential scanning calorimetry （DSC） and transmission electron microscopy （TEM）. The results indicated that the as-cast Nd60Fe20Al10Ni10- xYx （x = 0, 2） amorphous alloys were fabricated with some quenched-in crystals which could be restrained by Y. With the effect of Y, both the crystallization temperature and the exothermic peak shifted to a higher temperature, illustrating that the thermal stability could be improved. The Y addition changed crystallization mode and final crystallization product. And the crystallites in the amorphous matrix became more homogeneous and smaller. Meanwhile, the addition of Y was useful for the passivation of oxygen in chemistry and then restrained the negative effect of oxygen. The activation energies of crystallization start and peak were 1. 21 and 1.16 eV, respectively, according to Kissinger equation.