熔体冷速对Co48Cr15Mo14C15B6Er2块体非晶合金晶化及磁性能的影响

Effect of Melt Cooling Rate on Crystallization and Magnetic Properties of Co48Cr15Mo14C15B6Er2 Bulk Metallic Glass

摘要:

分别用单辊甩带法和铜模铸造法制备了Co48Cr15Mo14C15B6Er2非晶合金薄带以及Φ2 mm和Φ7 mm的非晶圆棒。利用差热分析仪和振动样品磁强计研究了冷却速率对Co48Cr15Mo14C15B6Er2非晶合金的晶化动力学及磁性能的影响。结果发现，冷却速率对晶化动力学有显著影响。对非等温晶化来说，随着冷速降低，试样的玻璃转变温度下降，玻璃转变激活能减小。虽然晶化峰值温度不受冷速的影响，但是晶化激活能随冷速降低而降低。对等温晶化来说，虽然不同冷速条件下制备的试样都表现出扩散控制的晶核三维长大过程，但

Abstract:

The Co48Cr15Mo14C15B6Er2 amorphous ribbon and rods with diameters of 2mm and 7mm were prepared by melt spinning and copper mold casting. The different Scanning calorimetry and the vibrating sample magnetometer were employed to investigate the effect of cooling rate on crystallization kinetics and magnetic properties of metallic Co48Cr15Mo14C15B6Er2 glass. It was found that the cooling rate had significant influence on the crystallization kinetics. In the case of non-isothermal crystallization process, the glass transition temperature and the activation energy for the glass transition decreased with decreasing of cooling rate. The activation energy for crystallization also decreased with decreasing of cooling rate, in despite of that the peak temperature of crystallization was independent of cooling rate. Although the isothermal crystallization was governed by diffusion-controlled three-dimensional growth with decreasing of nucleation rate for Co48Cr15Mo14C15B6Er2 glasses under different cooling rates, how rapidly the nucleation rate decreased was related to cooling rate. The more rapid the cooling rate was, the faster the decrease of the rate was. The magnetic properties of Co48Cr15Mo14C15B6Er2 glass was significantly affected by cooling rate. The sample obtained at high cooling rate took on paramagnetic property, whereas the sample obtained at low cooling rate took on ferromagnetic property. The saturation magnetization increased with decreasing of cooling rate.