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

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.

Key words:TiC/Fe composites; pressureless sintering; microstructure; mechanical properties