摘要
采用机械合金化及热压方法制备了纳米晶 Mg2Si 块体材料, 利用 X 射线衍射(XRD)、X 射线能谱(EDS)分析、场发射扫描电镜(FE SEM)及宏观密度测定对合成粉体及块体样品的微结构进行了表征。结果表明:正己烷作为合金化过程控制剂能有效避免粉体板结、团聚及防止合成粉体的氧化; 合适的工艺参数(如配球、球料比及球磨转速)可有效促进合金化和降低杂质含量; 配镁量对获得纯相 Mg2Si块体至关重要; 热压压力增大能显著提高Mg2Si块体的致密度; 在1.5 GPa压力热压获得了相对密度大于 98%、晶粒度为 69 nm的纯相纳米晶Mg2Si块体。
Bulk nanocrystalline Mg_2Si was prepared by mechanical alloying and hot-pressing, and its microstructures were characterized by X-ray diffraction, X-ray dispersive energy spectroscopy, field-emission scanning microscopy and density measurements. The results indicate that as process controlling agent n-hexane can inhibit agglomeration and avoid oxidation of the produced powders. Proper choice of technique parameters can facilitate the alloying process and reduce impurities. It is also found that surplus Mg is imperative in obtaining monolithic Mg_2Si phase. The increase in the pressure of hot-pressing can lead to significant densification of the bulk specimens. After hot-pressed at 400℃ under pressure of 1.5GPa, bulk Mg_2Si with a relative density higher than 98% and a mean grain size of 69nm was obtained.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2005年第3期380-385,共6页
The Chinese Journal of Nonferrous Metals
基金
国家自然科学基金资助项目(50371081)
关键词
MG2SI
机械合金化
热压
纳米晶
Mg_2Si
mechanical alloying
hot-pressing
nanocrystals
