原位自生TiC和(Ti,W)C增强Fe基复合材料的研究

利用块体原材料原位合成10%TiC-Fe和(Ti,W)C-Fe两种复合材料,采用扫描电镜分析了复合材料的微观结构,利用X射线分析了相组成.结果表明,在TiC-Fe复合材料中,TiC作为唯一的第二相呈现粒状和条状两种形态.分析认为,粒状相为亚共晶相,而条状第二相为共晶相.通过用W替代部分Ti,成功地制备了10%(Ti,W)C-Fe复合材料,其中(Ti,W)C作为唯一的第二相比较均匀地分布在Fe基体中,其形态大部分呈粒状,条状相较少.在粒状(Ti,W)C相中,中心富Fe,而边缘W、Ti和C元素的分布是均匀的.与TiC相比,(Ti,W)C的密度更接近Fe,更适合作为大型铸件的增强相.

In-situ Synthesis of TiC and (Ti,W) C Reinforced Iron Matrix Composites

In-situ synthesis of 10% TiC/Fe and (Ti,W)C/Fe composites made in block raw materials was investigated using scanning electron microscopy and X-ray diffraction. The results show that in the TiC-Fe composite, the TiC, as only second phase is in two kinds of morphologies, i.e. spherulic and rod-like ones. It is thought that the spherulic TiC is a hypoeutectic phase and the rod-like one is a eutectic phase. The (Ti,W)C reinforcements in (Ti,W)C/Fe composites, as only one second phase, are more homogeneously distributed in iron matrix by replacing part of titanium for tungsten in TiC/Fe composite. Most of the reinforcements are spherulic, rod-like are few. Titanium, tungsten and carbon are homogeneously distributed within the spherulic (Ti,W)C phase except that its core is rich in iron. Comparing with the TiC, the (Ti,W)C phase has a density matchable for iron melt, which makes it more suitable for in-situ synthesis reinforcements in large size ingots of iron matrix composites. Therefore in-situ synthesis of the 10% (Ti,W)C-Fe composite in liquid iron is feasible.