(合肥工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院，合肥 230009)
摘 要: 利用高能球磨和后續(xù)熱處理技術(shù)制備納米晶Fe50Al50(摩爾分?jǐn)?shù)，%)合金粉體。采用X射線衍射、透射電鏡和掃描電鏡對元素混合粉在機(jī)械合金化過程中的結(jié)構(gòu)演變及熱處理對合金化粉體結(jié)構(gòu)的影響等進(jìn)行分析，討論其機(jī)械合金化合成機(jī)制。結(jié)果表明：球磨過程中Al向Fe中擴(kuò)散，形成Fe(Al)固溶體。機(jī)械合金化合成Fe(Al)遵循連續(xù)擴(kuò)散混合機(jī)制；球磨30 h后，粉體主要由納米晶Fe(Al)構(gòu)成，晶粒尺寸5.65 nm；熱處理導(dǎo)致Fe(Al)納米晶粉體有序度提高，轉(zhuǎn)變?yōu)橛行虻?/FONT>B2型FeAl金屬間化合物，粉體的晶粒尺寸增大，但仍在納米尺度范圍。
關(guān)鍵字: Fe50Al50；機(jī)械合金化；結(jié)構(gòu)演變；合金化機(jī)制；熱處理
of Fe50Al50 binary system
ZHENG Zhi-xiang
（School of Materials Science and Engineering, Hefei University of Technology,
Hefei 230009, China）
Abstract:Nanocrystalline Fe50Al50 (mole fraction, %) alloy powder was synthesized by high-energy ball milling and subsequent heat treating. Both the structural evolution of elemental powder during mechanical alloying and the effect of heat treatment on microstructure of as-milled powder were investigated by X-ray diffractometry (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The mechanical alloying mechanism of Fe50Al50 powder during ball milling was also discussed. The results show that the diffusion of Al into Fe lattice occurs during milling, leading to the formation of Fe(Al) solid solution. The process was controlled by continuous diffusion mixing mechanism. After milling for 30 h, the powder is composed of Fe(Al) with grain size of 5.65 nm. The transformation from the disordered Fe(Al) solid solution into the ordered B2-FeAl intermetallic compound occurs after heat treating, accompanying with the growth of B2-FeAl grain which is still in nanometer scale.
Key words: Fe50Al50; mechanical alloying; structural evolution; reaction mechanism; heat treatment
