Mechanical behavior of porous Mg-10Zn bone scaffolds fabricated via low-temperature powder metallurgy

Abstract

The development of bone scaffold materials must balance the conflict between high porosity for biological integration and sufficient mechanical strength to support physiological loads. This reasoning underpins the investigation of biodegradable magnesium alloys, which offer biocompatibility and a bone-like modulus to prevent stress-shielding. This study focuses on the low-temperature  fabrication of a porous Mg-10 wt% Zn alloy scaffold via powder metallurgy route, with the purpose of  rigorously characterizing its mechanical properties and establish a critical structure-property relationships fabricated for bone implant applications. Therefore, scaffolds with target porosities of 40%, 60%, and 70% were fabricated, with the resultant architectural analysis confirming achieved porosities of 40.65%, 60.38%, and 68.70%, respectively. Their mechanical performance was evaluated through Vickers microhardness measurements and uniaxial compressive testing. Interestingly, the microhardness of the scaffolds remained nearly constant at approximately 42.3 ± 3.0 HV, irrespective of porosity. Whereas, the compressive strength demonstrated a predictable decline with increasing porosity, from 20.11 ± 0.40 MPa to 3.81 ± 0.45 MPa. Crucially, all three scaffold variants exhibited compressive strength and elastic modulus values that fall within the documented range for human cancellous bone. The results demonstrate that low-temperature fabricated Mg-10 wt% Zn scaffolds provide tunable porosity and predictable mechanical performance, offering a basis for future investigations into their degradation behavior and biological response.