Effect Of Structural Parameters On Mechanical Behaviors Of Ordered Porous Copper

Porous metals are considered as a new engineering material in many industry fields because of advantages like low density, high specific strength, large specific surface area and low thermal conductivity. Ordered porous metal is a new kind of porous material, which is characterized by cylindrical pores arranged directionally in the matrix. This unique pore structure is expected to give completely different mechanical behaviors compared with that of traditional porous material.Ordered porous copper with various structural parameters was fabricated by metal-gas eutectic unidirectional solidification technique. Tensile and compressive tests were conducted in room temperature to systematically investigate the effects of structural parameters such as porosity, load direction on mechanical behaviors of ordered porous copper. The tensile and compressive models were established by Finite Element Simulation (FES) for wider range of porosities. The results of FES could server as a supplement for experimental data.The tensile properties of ordered porous copper depend on the porosity and the Angle between Load direction and Pores axis (ALP). The tensile properties decrease linearly with the increasing porosity and show apparent anisotropic behavior. The tensile properties of the specimens with ALP of 0°are the best, while that of 90°are the worst. Ultimate tensile strength from FES, experiment and mathematic models are consistent well each other when the ALP is 0°. Ultimate tensile strengths obtained from stress concentration model are fit well with the experimental data with the ALP of 45°, while the stress concentration model are more consistent with the ALP of 90°. The results from FES fit well with that from area bearing model.The compressive properties of ordered porous copper are decreased with the increasing of porosity. The yield strength, compressive strength and absorbed energy of porous copper are anisotropic in compressive process due to difference of deformation, effective bearing area, grain orientation and stress concentration. The highest compressive properties are achieved in samples with ALP of 0°, and the compressive properties drop down as the ALP increases from 0°to 45°,60°and 90° respectively. Compressive mechanical models of ordered porous copper with ALP of 0°,45°and 90°are established by numerical analysis. The calculated stress-strain curves are well consistent with experimental results.The deformation behavior of ALP of 0°is characterized by bending of pore structures, which involves a drum shaped expansion of pore walls and subsequent destruction of pore structure. While that in ALP of 90°, the compressive processing is characterized by collapsing of pore walls and subsequent overlaying of pore walls. The deformation of the samples with ALP between 0°and 90°combine above two deformation mechanisms. The Deformation mechanisms analyzed by FES are well consistent with experiment process for the samples with ALP of 0°and 90°.