摘要
采用扫描电镜(SEM)、显微硬度分析、X-ray衍射和差热分析(DTA)技术研究了Ti-46at%Al混合粉末机械合金化过程中的显微组织演变。结果表明:随着球磨过程的进行,Ti-46at%Al颗粒逐渐等轴化,粒度变小,粒度分布变窄;显微硬度增大,硬度分布和颗粒内成分逐渐均匀。经过60h高能球磨,Al元素完全固溶入Ti晶格内,形成纳米Ti(Al)过饱和固溶体,同时,有非晶相形成;球磨至100h,形成完全非晶相。非晶相的形成是界面处非平衡扩散的结果,在Ti-46at%Al合金中,机械合金化致非晶的晶粒条件是:晶粒尺寸15nm。
Blended elemental powder with the nominal composition (at%) Ti(54)Al(46) was mechanically alloyed in a planetary ball milling system for up to 100h. The structure evolution in the powder was characterized by scanning electron microscope, micro-hardness analysis, X-ray diffraction and differential thermal analysis techniques. It was found that with increased milling time, powders became equiaxed and the distribution of particle size became narrow; the micro-hardness of powders increased and the distribution of micro-hardness of different particles became uniform. After 60h milling, elemental powders were progressively transformed into nanocrystalline Ti (Al) supersaturated solid solution, then into amorphous phase which was attributed to the fine grain size, and the grain size condition for formation of amorphous phase in this system is less than or equal to 15nm.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2002年第6期440-444,共5页
Rare Metal Materials and Engineering
基金
国家863计划项目资助(715-005-0040)
