Effect of Particle Size Distribution on Microstructure and Mechanical Properties of Spark-Plasma-Sintered Titanium from CP-Ti Powders

Abstract

The aim of this study was to determine the effect of particle size distribution on the microstructure and mechanical properties of spark-plasma-sintered titanium made from commercial pure titanium (CP-Ti) powders. The spark plasma sintering (SPS) of 100-mesh, 200-mesh, 325-mesh CF-Ti powders and mixtures thereof (100-mesh and 325-mesh powders mixed in weight ratios of 3:7, 5:5, and 7:3) was carried out in a flowing atmosphere of Ar + H-2 gas at 800-850 degrees C under a pressure of 30 MPa. Dense titanium with a relative density of up to 99% was found to form for SPS conditions of over 850 C and 30 MPa. The sintered body showed a difference in sintered properties depending on the particle size of the powder: the smaller the particle size, the more rapid the densification, and in terms of the grain size of the sintered body, equiaxed grain of about 20-40 gm in diameter was formed regardless of the particle size distribution of the powder Regarding the hardness and tensile properties in the fully densified sintered body, smaller average particle sizes gave rise to higher values because of the increase in the content of interstitial solid solution and the formation of a homogeneous and fine-grained structure through the rapid densification process.