高体积含量TiC/Fe复合材料的制备及力学性能

The fabrication and mechanical properties of high volume content of TiC reinforced Fe matrix composites

摘要:

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437 MPa；80 %TiC/Fe的维氏硬度最大，为12.2 GPa。

Abstract:

TiC/Fe composites have been fabricated by planetary ball milling, cold-pressing and pressureless sintering, which used the mixture of TiC powders, reduced iron powders and carbonyl iron powders. The effect of carbonyl iron powder volume contents, sintering temperature and TiC volume contents on microstructure and mechanical properties of the composites was investigated. The results demonstrated that when carbonyl iron powders accounted for 60% volume fraction of Fe matrix powders, it was the optimal proportion for the properties of TiC/Fe compoaites. The relative density, Vickers hardness and bending strength of composites were improved with increasing temperature from 1460 °C to 1500 °C. Further increasing temperature to 1530 °C caused the mechanical properties decreased. The relative density and bending strength of 70 vol. % TiC/Fe were both to be maximized: 99.5% and 437 MPa at the temperature of 1500 °C. The Vickers hardness of 80 vol. % TiC/Fe reached the peak of 12.2 GPa at 1500 °C.