原位制备Fe(TiC)_p复合材料中增强相颗粒的组织遗传性及调控技术

以羰基Fe粉、Ti粉及C粉为原料,采用真空原位反应烧结法制备颗粒增强型Fe(TiC)_p复合材料。对微观组织的观察和元素分析发现,原料Ti粉对TiC增强颗粒的形貌和粒径具有较明显的遗传性。对这一组织遗传性,从反应热力学和扩散动力学方面给出解释,并基于此认识,设计原料Ti粉的球磨细化预处理工序。经预处理后原位反应烧结材料的致密度明显提升,并能够在铁基体中形成分散度更高、尺度更细小、且近球形的TiC增强颗粒,从而使复合材料的硬度从HV99.4提高到HV152.3,抗弯强度从550 MPa提高到935 MPa。

Microstructural heredity and controlling of strengthening particles in Fe(TiC)p composites fabricated by in-situ reaction

A particle-reinforced Fe(TiC)p composite was fabricated through in-situ reaction sintering (IRS) of Fe, Ti, and C powders in vacuum furnace. Microstructural and elemental analyses suggest the strong heredity of particle morphology and size of in-situ formed TiC from the raw Ti powders. An understanding of this microstructural heredity was explored from reaction thermodynamics and diffusion kinetics, and based on which, the pretreatment of refining the raw Ti powders by ball milling was suggested. After the pretreatment, the in-situ reaction sintering density is significantly improved. A much more dispersive distribution of finer and near-spherical TiC particles in iron matrix is also achieved. As results, the hardness (HV) of the composite improved from 99.4 to 152.3 and the bending strength improved from 550 to 935 MPa.