Effect of compaction pressure and heating rate on microstructure and mechanical properties of spark plasma sintered Ti6Al4V alloy

In the present paper, the use of spark plasma sintering on Ti6Al4V powder was investigated. Sintering experiments were conducted at the temperature of 1000°C for 5 min. The simultaneous effect of compaction pressures of 5, 25 and 50 MPa and heating rates of 200, 300 and 400°C/min on the structure, density, microhardness, elastic modulus and compressive strength were analyzed and ranged between 4.14 and 4.43 g/cm3, 293 and 373 HV0.05, 116 and 142 GPa, 1169 and 1414 MPa respectively. With increasing compaction pressure, the effect of an increase in grain size was observed. The obtained results show that very good mechanical properties can be achieved using spark plasma sintering at a rapid heating rate and already with the 25 MPa compaction pressure. The best results of microhardness (373 HV0.05) and compressive strength (1414 MPa) with an elastic modulus of 138 GPa were obtained by the compacts sintered under the compaction pressure of 50 MPa and at the heating rate of 300°C/min.