Reactive sintering of TiC-based cermets by using iron, titanium and carbon powders

Abstract

It has been carried out to investigate the production parameters of TiC-reinforced iron-based cermets through the reactive sintering technique in the present MSc thesis. Based on the analysis of reactive sintering parameters, it was tried to improve the physical property such as density and mechanical property such as hardness according to the results obtained. The cermet which was produced with optimum parameters as a result of the study is planned to be a ready-to-use. The reaction between Ti and C occurring on sintering is highly exothermic and the energy which was released in the reaction was considered as an extra driving force for sintering. In this respect, it was aimed to observe an enhancement on the final physical and mechanical properties as a result of reactions taking place during sintering processes. In experiments, titanium, graphite, and iron were used as raw materials. Mixing operations were applied as uniaxial mixing in a dry medium to homogenize raw materials. Various ratios of raw materials were used to obtain different TiC percentages in final products. Powder mixtures were pressed in a uniaxial press under constant pressure to obtain green pellets. Interactions between reactant powders were investigated by developing thermochemical models at high temperatures. In the next step, the reactive sintering processes were realized for the same duration at various synthesis-sintering temperatures. Reactive sintering experiments were conducted in a vacuum sintering furnace allowing carrying out experiments under an inert gas atmosphere. Depending on these experimental parameters, density and hardness measurements were conducted in sintered pellets. To take micrographs from sintered pellets, the SEM-EDS technique and optical microscopy were used. XRD method was also be utilized to characterize final phase properties. The results were compared to the literature for benchmarking. In this thesis, together with obtaining high mechanical properties, it is economical and bulk producibility is aimed.