Cryomilling and Characterization of Metal/ceramic Powders
Al/Fe2O3 thermite powders were prepared by cryomilling at liquid nitrogen temperature.The cryogenic temperature will restrain the mechanochemical reaction between alumina and iron oxide,leading to high reactivitive nanoscale powders.The size distribution of the powders was analyzed using laser particle size analyzer,and cryomilling was proved to be an effective method to prepare ultrafine powders.The differential scanning calorimetry (DSC) analysis indicated that the cryomilled powders get more fully-reacted,a larger proportion of solid-solid reaction and more heat release in the solid-liquid reaction,comparing with the powders milled at room temperaure.Furthermore,the reaction kinetics of Al-Fe2O3 system is analyzed by a model-free Starink method.The activation energy for solid-solid reaction of 2Al-Fe2O3 thermite mixture cryomilled for 40 min is determined as 250 kJ/mol.The alternating gradient magnetometer (AGM) analysis shows that long time milling evoked the thermit reaction between Al and Fe2O3,leading to the increase in saturation magnetization (Ms) and remanent magnetization (Mr).
Al/Fe2O3 powder Cryomilling Reaction kinetics Magnetic properties
Qing Hou Zhi-cheng Shi Run-hua Fan Li-cheng Ju
Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials(Ministry of Education),Shandong University,Jinan,250061,China
国际会议
The Seventh China International Conference on High-Performance Ceramics (第七届先进陶瓷国际研讨会(CICC-7))
厦门
英文
127-131
2011-11-04（万方平台首次上网日期，不代表论文的发表时间）