Nb添加对Cu-Zr非晶合金玻璃转变和晶化动力学的影响

Effect of Nb addition on the glass transition and crystallization kinetics of bulk Cu-Zr metallic glasses

采用铜模吸铸法制备出直径为2mm的Cu50.3Zr49.7-xNbx(x=0,2)大块非晶合金,利用示差扫描量热分析(DSC)研究了2at%Nb元素添加对Cu-Zr非晶合金玻璃转变动力学和晶化动力学的影响,发现含Nb合金具有较低的脆性指数,和较高的晶化激活能.这表明微量Nb的添加提高了该二元Cu基非晶合金过冷金属液相的热稳定性,从而有利于其非晶合金的形成.

In the present work, bulk Cu50.3 Zr49.7-x Nbx （x = 0,2） amorphous alloys 2 mm in diameter were produced by copper mold suction casting. The effect of Nb addition on the glass transition as well as crystallization kinetics of the binary Cu based amorphous alloy has been investigated by using differential scanning calorimetry （DSC）. It is found that the alloy containing 2 % Nb has a lower fragility parameter m and higher crystallization activation energy Ec , which suggests that the thermal stability and hence the glass forming ability of the surpereooled metallic liquid for the Cu based alloy are enhanced by the addition of very small amounts of Nb element.