摘要
采用燃烧合成-热压工艺制备热电材料β-FeSi2,研究了热压温度和热压压力对铁硅间化合物相变的规律。利用X射线衍射仪和扫描电子显微镜分析了合成的铁硅间化合物的相组成及其微观结构形貌。结果表明:当铁硅原子比Fe∶Si为1∶3,添加0.50 at%的Cu时,燃烧合成的产物主要为α-Fe2Si5和Si。热压温度为760℃时α-Fe2Si5完全转变为β-FeSi2,且压力的升高有助于β-FeSi2生成和产物致密度的提高。α-Fe2Si5分解发生共析反应时,部分Si固溶于β-FeSi2内形成了β-FeSi2合金。另一部分Si微粒粘附于β-FeSi2颗粒上,Si在β相的弥散分布可提高热电优值。
Abstract：Thermoelectric material β-FeSi2 was prepared by the method of combustion synthesis-hot pressing. Effects of temperature and pressure of hot pressing on the phase transformation of Fe-Si intermetallics were studied. The phase composition and microstructure of Fe- Si intermetallics were investigated by means of X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The resuhs show that the main products of combustion synthesis are α-Fe2Si5 and Si when the atomic ratio of Fe to Si is 1：3 and 0.5 at% copper is doped. When the temperature is 760 ℃ , α-FeESi5 is completely transformed into β-FeSi2 , and increasing pressure is favourable for increase of products density and transformation of α-Fe2 Si5 to β-FeSi2. Euteetoid reaction of β-Fe2Si5 decomposition occurs to form β-FeSi2 and Si with part of the Si solutioned in β-FeSi2 , and the other Si particles stick on the β-FeSi/particles, which can increase thermoelectric figure of merit.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2013年第1期1-5,共5页
Transactions of Materials and Heat Treatment
基金
国家自然科学基金项目(51161012)
关键词
Β-FESI2
热压
温度
相转变
微观结构
β-FeSi2
hot pressing
temperature
phase transformation
microstructure
