TiC/Cr18Ni8不锈钢钢结硬质合金原位反应合成研究

Study on in situ reactive synthesis of TiC/Cr18Ni8 steel bonded carbide

以钛铁粉、铬铁粉、铁粉、镍粉和胶体石墨等为原料,原位反应合成了TiC/不锈钢钢结硬质合金,并用扫描电镜(SEM)、X射线衍射等对烧结试样进行了组织结构分析.结果表明:钢结硬质合金主要相组成为TiC和Fe-Cr-Ni固熔体,TiC颗粒细小,形状规则,最大约3μm,大部分在1μm以下;随烧结温度的升高,钢结硬质合金的孔隙度减小,密度和硬度升高,但TiC颗粒略有长大.在相同烧结条件下,C/Ti原子比为0.9的钢结硬质合金的密度和硬度比C/Ti原子比为1.0的钢结硬质合金高,所合成的TiC颗粒更细小,分布更均匀.

TiC/Cr18Ni8 steel bonded carbides were in situ synthesized by vacuum sintering the compacts of mixed ferrotitanium, ferrochromium, iron and carbon powers, etc. The microstructure of the steel bonded carbides was analyzed by scanning electron microscope （ SEM）, X - ray diffraction （XRD）. The results show that ： the synthesized TiC particles are fine, most of which are no more than 1μm. The size of TiC particles increases with the increase of sintering temperature. Under the same sintering conditions, the steel bonded carbides with C/Ti atomic ratio 0.9 have higher density and hardness, better refinement and distribution uniformity of TiC particles than those with C/Ti atomic ratio 1.0.