B、N小原子对Dy(Gd)基合金非晶形成能力和晶化动力学的影响

Effect of Small Atoms of B and N on Glass-Forming Ability and Crystallization Kinetics of Dy(Gd)-Based Alloys

采用水冷铜模吸铸法制备添加B、N小原子的Dy(Gd)基合金系样品,利用X射线衍射(XRD)仪检测合金的相结构,利用示差扫描量热(DSC)仪研究合金的玻璃转变和晶化行为,用Kissinger和Arrehenius方程分别计算出合金的晶化激活能、频率因子、晶化速率常数等晶化动力学参数。结果表明:Dy31Gd25Co20Al24合金中添加小原子B和N,晶化模式发生改变;合金的过冷液相区和晶化激活能先减小后增大;加入B原子,合金的晶化速率常数先增大后减小,加入N原子,合金的晶化速率常数先减小后增大。

A series of Dy（Gd）-based bulk metallic glasses with small atoms of B and N were prepared by casting the melt ingots into a water-cooled copper mould.Their phase structure was analyzed by X-ray diffraction.The glass transition and crystallization behavior were measured by differential scanning calorimetry（DSC）.Kinetics parameters of crystallization such as crystallization activation energy,frequency factor and crystallization rate constant were calculated by Kissinger equation and Arrehenius law.The results show that for the Dy31Gd25Co20Al24 alloy with addition of small atoms of B and N,the crystallization model changed;both the supercooled liquid region and crystallization activation energy were first decreased and then increased;with added B atom,crystallization rate constant of the alloy was first increased and then decreased;while with added N atom,crystallization rate constant was first decreased and then increased.