Influence of milling time on the processing of Fe–TiCN composites

Fe–TiCN composites were prepared according to conventional powder metallurgical techniques. Composite powders of iron and titanium carbonitride have been prepared by a high-energy milling route. A proper characterisation of powders is necessary and it was carried out by different means: scanning electron microscopy (SEM) to study the particle morphology and microstructure; X-ray diffraction (XRD) to find possible transformations during the milling; chemical analyses to determine the percentage of oxygen, carbon and nitrogen; and particle size distribution. The sintering process was carried out at different temperatures under N2–10H2–0.1CH4 atmosphere. The density, chemical composition and Vickers hardness (HV30) was measured, and their microstructures were observed by using scanning electron microscopy. As a result of the study it is clear that the higher the C/N ratio, higher hardness are related with the microstructure; an increase in the C/N ratio, the hard phase is finer and more disperse throughout the matrix.