SPS法で製造したTi–6%Al–4%V合金多孔質焼結材の組織と力学的特性

抄録

The purpose of this study is to estimate the elastic modulus, strength and ductility of porous Ti6Al4 V alloy prepared by spark plasma sintering process using gas atomized powders. Porous alloys have nominally 0, 20, 30 and 40% porosities after sintering. Three-point bending test has been carried out to evaluate the effects of porosity on strength to biomaterials application. In order to investigate an effect of microstructures on materials properties, tensile properties and elastic modulus have also been measured with 20% porosity Ti6Al4 V/PMMA composites and 20% porosity Ti6Al4 V alloy treated by solid solutioning, annealing and ageing respectively. Bending strength lineally decreases with increasing porosity at a range from 20 to 40%. It has been showed that all heat treated or composites specimens have a superior strength property compared with human cortical bone. Elastic modulus has been estimated around 40~48 GPa, and failure strain has a range from 0.8 to 1.0% in all specimens. Both tensile strength and strain depend on porosity rather than the microstructure of particles after heat treatment. 20% porosity Ti6Al4 V/PMMA composites give a smooth surface to porous samples without a degradation of strength characteristics. Ductile fractures are observed on particle surfaces after tensile test, and it is indicated that a bonding between particles after sintering is strong.