摘要
采用电场激活自蔓延高温燃烧合成(FASHS)技术制备了致密度高、且晶粒细小的TiC-Fe-Ni系梯度功能材料。外 加电场通过焦耳加热效应及电流分配作用使蔓延波自持续下去,克服了SHS的热力学及动力学局限性,提高反应率;试验 发现,电场促使梯度过渡层在宏观上呈均匀分布和稳定过渡;反应前沿的成分梯度是传质现象的驱动力,它促使Ni3Ti、 Fe5C2的生成。电场通过增加电子和离子的运动速度,加快了离子的交换过程,使反应更加充分,生成物的成分更均匀。
In this paper, high compacted and fine-grained TiC/Ni/Fe functional gradient materials（FGM） was prepared by electric field-activated self-propagating high-temperature synthesis（FASHS）. The imposed field makes the reaction wave propagate under the effect of Joule heating and the current distribution, overcomes the limits of thermodynamic and kinetic of SHS and increases reaction speed. It indicates that the transitional layers appear more smooth and uniform macres-copieally under the effect of electric field. The gradient of composition in the reaction front is the driving force of mass transferring, which promotes the generating of Ni3Ti, FesC2. The field promotes the exchange of ions and improves the plenitude of reaction and the uniformity of products by accelerating the diffusion speed of electrons and ions,
出处
《兵器材料科学与工程》
CAS
CSCD
北大核心
2005年第6期10-13,共4页
Ordnance Material Science and Engineering
基金
国家自然科学基金项目(50375105)
山西省自然科学基金项目(20031051)
