交叉轧制钼带冷深冲性能及微观组织研究

采用单辊急冷法制备了Fe71Nb6B23非晶薄带,并用差示扫描热分析法(DSC)研究了该非晶合金的变温晶化动力学.从DSC曲线可知,玻璃化转变温度Tg、晶化起始温度Tx和晶化峰值温度Tp均随着升温速率的增加向高温方向移动,这些特征温度均具有明显的动力学效应.分别利用Kissinger方程和Ozawa方程计算了该Fe基非晶薄带的玻璃化转变激活能Eg、晶化激活能Ex和激活能Ep,并解释了此非晶合金具有高的热稳定性的热力学机制.结果表明:两种方程计算得出的Ex均大于Ep,表明该合金的形核过程比晶粒长大更为困难;晶化的动力学效应较玻璃化转变更为明显.

Study on Cold Deep Drawing Performance and Microstructures of Cross-Rolled Molybdenum Strip

The Fe71Nb6B23 amorphous ribbons were prepared using melt spinning method. Differential scanning calorimeter was applied to investigate non-isothermal crystallization kinetics of the amorphous ribbons at different heating rates from 10 to 40 K/min. As the heating rate is increased, the values of Tg, Tx, and Tp are shifted toward a higher temperature region, suggesting that the amorphous ribbons have obvious crystallization kinetics. The effective activation energies including Eg, Ex and Ep were calculated with Kissinger and Ozawa equations by means of DSC traces at different step-up temperature rates. Thermodynamical mechanism of the amorphous ribbons was explained. The results reveal that the nucleation is quite more difficult than growth of the grains because Ex is larger than Ep. And the crystallization kinetics is more obvious than that of glass transition