Interfacial Properties of Bonded Dissimilar Materials Fabricated via Spark Plasma Sintering

Abstract

This paper deals with characterization of interfacial properties of bonded dissimilar materials to fabricate biocompatible composites and functionally graded materials(FGMs) with high mechanical performance. To develop biomaterials with conflicting properties, such as hardness and toughness, for artificial bone, much attention has been paid to the composites and FGMs consisting of biocompatible ceramics and metals. Their mechanical properties are influenced by interface of dissimilar materials, and the interfacial properties should be evaluated. Hence, this study aims to investigate the influence of material combination on interfacial strength and toughness of bonded dissimilar materials consisting of four types of biocompatible materials: titanium, type 316L stainless steel, partially stabilized zirconia, and alumina. The bonded dissimilar materials were fabricated via spark plasma sintering technique, which is a powder metallurgy technique utilizing uniaxial load and pulsed direct current in vacuum. The interfacial strength and toughness of the materials were evaluated via compression-bending testing and indentation testing, respectively. The distributions of elements near the interfaces due to atomic diffusion during sintering were evaluated, and the influence of material combination on interfacial properties was discussed based on the distributions. As a result, it was found that the mechanical properties of all interfaces became lower than those of the monolithic materials, and the amount of reduction in mechanical properties was dependent on the material combination. If the atom diffusion occurred on both sides of the interface, the interfacial toughness and strength tended to be relatively high.