Zr-Al-Ni-Cu(Nb,Ti)大块非晶玻璃转变的动力学性质

Glass transition kinetic property of novel bulk Zr-Al-Ni-Cu (Nb,Ti) amorphous alloy

以Zr Al Ni Cu(Nb ,Ti)大块非晶合金差示扫描量热分析实验为基础 ,利用Lasocka方程、Kissinger方程及Vogel Fulcher Tamman(VFT)方程对其玻璃转变的动力学性质从不同方面进行了研究 .分析结果表明 :玻璃转变表观激活能越小 ,则晶化转变激活能越大 ,表现出相反的难易程度 ,且玻璃转变表观激活能数值远较传统非晶要小 ,验证了大块非晶合金独特的结构特点及玻璃形成能力 (GFA)强的原因 .利用VFT方程对玻璃转变弛豫时间与升温速度的VFT曲线进行了拟合 ,所算得的玻璃脆性参数m均在 30左右 ,反映了Zr Al Ni Cu(Nb ,Ti)非晶合金强的脆性属性 .玻璃转变处Lasocka关系的B值、原子表观激活能及玻璃脆性参数均反映了相同的GFA大小趋势 ,从不同方面进一步揭示了非晶合金玻璃转变区间的动力学行为与GFA之间的密切联系 。

The kinetic property during the glass transition process of Zr_Al_Ni_Cu (Nb,Ti) amorphous alloys was systematically investigated by differential scanning calorimetry method. The activation energy (ΔE) at the glass transition temperature was much smaller than tradition amorphous alloys and have different magnitude compared to ΔE value at T x. These reveal that the bulk amorphous alloys show special structure characteristics and that is the reason of its big glass_forming ability. The Vogel_Fulcher_Tammann fits to the experimental data are given by the full curves and the fragility parameter m value was calculated to be about 30, reflecting its “strong' liquid property in deep_undercooled region. The B value of Lasocka function,atom activation energy and glass fragility parameter reveal a close relationship between kinetic behavior at glass transition and the glass_forming ability. So it could be used as an important judgment for glass_forming ability.