Effect of sintering conditions on the microstructural and mechanical characteristics of porous magnesium materials prepared by powder metallurgy

摘要

There has recently been an increased demand for porous magnesium materials in many applications, especially in themedical field. Powder metallurgy appears to be a promising approach for the preparation of suchmaterials. Many works have dealt with the preparation of porousmagnesium; however, the effect of sintering conditions on material properties has rarely been investigated. In this work, we investigated porous magnesium samples that were prepared by powder metallurgy using ammoniumbicarbonate spacer particles. The effects of the purity of the argon atmosphere and sintering time on themicrostructure (SEM, EDX and XRD) andmechanical behaviour (universal loadingmachine and Vickers hardness tester) of porousmagnesiumwere studied. The porosities of the prepared samples ranged from 24 to 29 vol.% depending on the sintering conditions. The purity of atmosphere played a significant role when the sintering time exceeded 6 h. Under a gettered argon atmosphere, a prolonged sintering time enhanced diffusion connections between magnesium particles and improved the mechanical properties of the samples, whereas under a technical argon atmosphere, oxidation at the particle surfaces caused deterioration in the mechanical properties of the samples. These results suggest that a refined atmosphere is required to improve the mechanical properties of porous magnesium.