高体积含量TiC/Fe复合材料的制备及力学性能

Fabrication and Mechanical Properties of High Volume Content TiC Reinforced Fe Matrix Composites

以TiC粉、还原铁粉和羰基铁粉为原料,采用行星球磨混料、冷压成型后无压烧结工艺制备了TiC颗粒体积含量为70%~90%的TiC/Fe复合材料,重点研究了羰基铁粉添加量、烧结温度及TiC体积含量对TiC/Fe复合材料的微观结构和力学性能的影响。结果表明:羰基铁粉的最佳添加量为铁基体粉体积含量的60%。当TiC体积含量一定时,随烧结温度的升高,TiC/Fe复合材料的相对密度、维氏硬度与弯曲强度均先增大后减小,经1500℃烧结后,复合材料的综合性能最佳。其中,70%TiC/Fe的相对密度及弯曲强度最高,分别为99.5%和437MPa;80%TiC/Fe的维氏硬度最大,为12.2GPa。

TiC/Fe composites have been fabricated by planetary ball milling,cold-pressing and pressureless sintering,using the mixture of TiC powders,reduced iron powders and carbonyl iron powders as starting materials. The effect of carbonyl iron powder volume content,sintering temperature and TiC volume content on microstructure and mechanical properties of the composites was investigated. The results demonstrate that the optimal proportion of carbonyl iron powders is 60% volume fraction of Fe matrix powders. The relative density,Vickers hardness and bending strength of the composites are improved with increasing temperature from 1460 °C to 1500 °C,but they decrease with further increasing of temperature. The comprehensive properties are the best when the sintering temperature is 1500 °C. The relative density and bending strength of 70 vol% TiC/Fe are both maximum,which are 99.5% and 437 MPa,respectively at the temperature of 1500 °C. The Vickers hardness of 80 vol% TiC/Fe reaches the peak of 12.2 GPa at 1500 °C.