特種燒結(jié)及磁性能
劉會(huì)群1， 吳標(biāo)理1， 吳 煒1， 馬 瑞1
( 1. 中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083；
2. 中國科學(xué)院 上海硅酸鹽研究所 特種材料研究與發(fā)展中心，
上海 200050)
摘 要: 研究了放電等離子燒結(jié)和高壓燒結(jié)工藝條件對MA Fe73.5Cu1Nb3Si13.5B9納米晶粉末的燒結(jié)塊體合金的組織結(jié)構(gòu)與磁性能的影響。 結(jié)果表明： 球磨70 h后， 獲得了單相α-Fe納米晶(約9.5 nm)過飽和固溶體粉末； DSC升溫曲線中， 出現(xiàn)4個(gè)不同強(qiáng)度的放熱峰， 依次發(fā)生了納米晶過飽和固溶體的結(jié)構(gòu)弛豫、 非晶晶化以及過飽和固溶體相析出等過程， 且相析出過程分兩個(gè)階段完成； 在p=30 MPa, t=5 min放電等離子燒結(jié)(SPS)條件下， 當(dāng)溫度達(dá)到1 050 ℃后， 可獲得相對密度為98.9%、 主相為α-Fe的納米晶(100 nm)塊體合金， 其中， Bs=1.34 T, Hc=7.34 kA/m， 在p=5.5 GPa, t=5 min條件下， 當(dāng)Pw=1 150 W后, 可獲得相對密度約99.1%、 單相α-Fe納米晶(21.4 nm)塊體合金， 其中， Bs=1.14 T, Hc=8.22 kA/m。
關(guān)鍵字: Fe基合金； 機(jī)械合金化； 納米晶； SPS燒結(jié)； 高壓燒結(jié)； 塊體合金； 磁性能
mechanical alloying Fe73.5Cu1Nb3Si13.5B9
nanocrystalline powder
LIU Hui-qun1, WU Biao-li1, WU Wei1, MA Rui1
（ 1. School of Materials Science and Engineering,
Central South University, Changsha 410083, China;
2.Special Materials Research and Development Centre,
Shanghai Institute of Ceramics, Chinese Academy of Science,
Shanghai 200050, China）
Abstract: The influence of spark plasma sintering and high-pressure sintering technique on microstructure and magnetic properties of bulk alloys of MA Fe73.5Cu1Nb3Si13.5B9 nanocrystalline powder were investigated. The results show that after milling for 70 h, the single phase α-Fe nanocrystalline supersaturate solid solution powder with average grain size 9.5 nm and bcc structure can be obtained. In DSC heating-up curve of MA powder, four exothermal peaks with different strength appear, which are corresponding to the structure relaxing process of distorted nanocrystalline supersaturate solid solution, crystallization process of trace amorphous phases and phase precipitation of supersaturate solid solution, respectively. The precipitation process of supersaturate solid solution is decided into two stages. Under the SPS sintering conditions at p=30 MPa, t=5 min, when sintering temperature is 1 050 ℃, nanocrystalline (100 nm) bulk alloy with relative density of 99% and main phase of α-Fe can be obtained, the magnetic properties of bulk alloy are: Bs=1.34 T, Hc=7.34 kA/m. Under the high-pressure sintering conditions of p=5.5 GPa, t=5 min, when Pw=1 150 W, single phase α-Fe nanocrystalline (21.4 nm) bulk alloy with relative density of 99.1% can be obtained, the magnetic properties of which are: Bs=1.14 T, Hc=8.22 kA/m.
Key words: Fe-based alloy; mechanical alloying; nanocrystalline; SPS sintering; high-pressure sintering; bulk alloy; magnetic properties
