Consolidation by electrical resistance sintering of Ti powder

In this study, commercially pure Ti powder was consolidated by the electrical resistance sintering (ERS) technique. This consolidation technique consists of the application of pressure (around 100 MPa) to a powder mass at the same time that the powder is heated by the passage of an electric current of high intensity (around 10 kA), low voltage (around 5 V) and a frequency of 50 Hz. Several current intensities and dwell times were tested during the consolidation process. The work includes a microstructural study of the most relevant characteristics of the compacts. Furthermore, the obtained compacts were mechanically characterised by the measurement of their hardness distribution and by an indirect tensile test. For all the compacts, the average hardness and the strength resulting from the indirect tensile test are empirically related to the global porosity of the compact and the electric energy supplied during the consolidation process. This energy is a function of the intensity of the electric current and the dwell time. These empirical relationships can be useful to select the best process conditions. The results were compared with values obtained for specimens prepared with the same powder by the conventional powder-metallurgy route of cold die pressing and furnace sintering.