Compressive behavior and vibration-damping properties of porous Ti-6Al-4V alloy manufactured by laser powder bed fusion

Abstract

• Compressive behavior of porous Ti-6Al-4 V alloy is governed by the relative densities. • Compression mechanism tends to be elasto-plastic in specimens with larger cell size. • Energy absorption capacity increases linearly with the as-manufactured density. • Natural frequency of cellular structure is proportional to the strength-weight ratio. • Cellular structures with larger cell size exhibit better damping abilities. Porous Ti-6Al-4V alloy with various cell geometries and cell sizes was manufactured by laser powder bed fusion (LPBF) technique, and the influence of the structural characteristics on the compressive behavior and vibration-damping abilities was systematically investigated. In terms of the compressive performance, both elasto-brittle and elasto-plastic features are observed from the compressive stress-strain curves and the corresponding transformation from elasto-brittle to elasto-plastic can be achieved by increasing the cell size. Moreover, the compressive performances are found to be closely related to the relative density determined by both the cell geometries and cell sizes of specimens. The energy absorption capability of each cellular structure increases linearly when increasing the as-manufactured density, while the energy absorption efficiency presents sensitivities to both the cell geometry and the cell size. The results also reveal that the variation of natural frequency is proportional to the specific strength (i.e., strength-weight ratio), and the cellular structure with larger cell size exhibits better damping ability than smaller sized structures.