Fe_2B-Mo_2FeB_2基金属陶瓷的显微组织与性能

Microstructure and properties of Fe_2B-Mo_2FeB_2 based cermets

采用XRD、SEM及EPMA等方法研究Fe2B-Mo2FeB2基系列金属陶瓷的显微组织与性能。结果表明:Fe2B-Mo2FeB2基系列金属陶瓷的相组成均为Fe2B相、Mo2FeB2相、Fe3B相及少量Fe基黏结相,C及Mo原子分别部分置换Fe3B相中的B及Fe原子是该相能稳定存在于室温的重要原因。随着Mo含量的增加,金属陶瓷的硬度略有提高,抗弯强度由371 MPa增至833 MPa,提高452 MPa,增幅达到121.8%;金属陶瓷中长棒状Mo2FeB2相与Fe3B相复合组织含量增加的同时,Fe2B相含量减少是金属陶瓷获得优异性能的原因。

The microstructures and properties of Fe2B-Mo2FeB2 based cermets were investigated by means of XRD, SEM, EPMA, and so on. The results show that Fe2B-Mo2FeB2 based cermets are composed of Fe2B, Mo2FeB2, Fe3B and a small amount of Fe based binder phase. The main reason why Fe3B, a metastable phase, is stable at room temperature is that some B and Fe atoms in Fe3B are replaced by C and Mo atoms, respectively. With the increase content of Mo, the hardness of cermets increases slightly, the transverse rupture strength is improved from 371 MPa to 833 MPa, the increasing rate is as high as 121.8%, the excellent property of cermets obtained is attributed to the increase of content of composed structure (Mo2FeB2+Fe3B), as well as the decrease of Fe2B phase content.