Mechanical Properties Directionality and Permeability of Fused Triply Periodic Minimal Surface Porous Scaffolds Fabricated by Selective Laser Melting

Titanium alloy porous scaffolds possessexcellent mechanicalpropertiesand biocompatibility, making them promising for applications in bonetissue engineering. The integration of triply periodic minimal surface(TPMS) with porous scaffolds provides a structural resemblance tothe trabecular and cortical bone structures of natural bone tissue,effectively reducing stress-shielding effects, enabling the scaffoldto withstand complex stress environments, and facilitating nutrienttransport. In this study, we designed fused porous scaffolds basedon the Gyroid and Diamond units within TPMS and fabricated samplesusing selective laser melting technology. The effects of the rotationdirection and angle of the inner-layer G unit on the elastic modulusof the fused TPMS porous scaffold were investigated through quasi-staticcompression experiments. Furthermore, the influence of the rotationdirection and angle of the inner-layer G unit on the permeability,pressure, and flow velocity of the fused TPMS porous scaffold structurewas studied using computational fluid dynamics (CFD) based on theNavier-Stokes model. The quasi-static compression experimentresults demonstrated that the yield strength of the fused TPMS porousscaffold ranged from 367.741 to 419.354 MPa, and the elastic modulusranged from 10.617 to 11.252 GPa, exhibiting stable mechanical performancein different loading directions. The CFD simulation results indicatedthat the permeability of the fused TPMS porous scaffold model rangedfrom 5.70015 x 10(-8) to 6.33725 x 10(-8) m(2). It can be observed that the fusedporous scaffold meets the requirements of the complex stress-bearingdemands of skeletal structures and complies with the permeabilityrequirements of human bone tissue.