Mechanical properties and microstructure of Fe3Al intermetallics fabricated by mechanical alloying and spark plasma sintering
(1.北京市北京科技大学材料科学与工程学院
2.School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China)
2.School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China)
Abstract: Fabrication technology and mechanical properties of the Fe3Al based alloys were studied by spark plasma sintering from elemental powders (Fe-30Al, volume fraction, %) and mechanically alloying powders. The mechanically alloying powders were processed by the high-energy ball milling the elemental mixture powders with the milling time of 5, 8 and 10 min, respectively. The spark plasma sintering process was performed under the pressure of 50 MPa at 1 050 ℃ for 5 min. The phase identification by X-ray diffraction presents the Fe reacts with Al completely during the processing time. The samples are nearly full density (e.g. the relative density of sinter of raw powder is 99%). The microstructure was observed by TEM. The mechanical properties were tested by three-point bending at room temperature in air. The results show that the mechanical properties are better (e.g. bend strength of 1 500 MPa ) than those of the ordinary Fe3Al casting.
Key words: iron aluminides; mechanical alloying; spark plasma sintering; bend strength; microstructure