On the physical and mechanical properties of spark plasma sintered pure Ti and Ti-TiB composite

Abstract

The physical and mechanical properties of spark plasma sintered pure Ti and Ti-TiB2 composite were investigated as a function of TiB2 concentration and sintering temperature. Experiments were conducted using the response surface methodology based on a full factorial design in order to model and evaluate the responses, namely sintered density, porosity, ultimate tensile strength, elongation, bending strength and micro-hardness. Analysis of variance was performed to evaluate the acceptability of the developed models. In order to confirm the accuracy of developed models, results of analyses by x-ray diffraction, optical and scanning electron microscopy from polished and fracture surfaces were investigated, in details. It was concluded that the sintering temperature has the most pronounced effect on the sintered density, porosity, and micro-hardness, while the TiB2 has the most pronounced effect on the ultimate tensile strength, elongation, and bending strength. Results showed that by introducing of TiB2 the strengthening occurs through grain refinement of matrix and in-situ formation of TiB needle like phases. Finally, it is concluded that the predicted values of responses obtained using mathematical models were in good agreement with the microstructural characteristics of sintered samples and optimum conditions for getting desired properties obtained using purposed models.