Structural Design and Mechanical Properties Analysis of Fused Triply Periodic Minimal Surface Porous Scaffold

In the field of bone tissue engineering, additive-manufactured metal scaffolds based on triply periodic minimal surfaces (TPMS) are expected to become a substitute for bone injury repair. The bone scaffolds based on the triply periodic minimal surfaces are similar in shape to natural bone tissue and also have many advantages in terms of strength and permeability, which have become one of the research hotspots in the field of additive manufacturing of metal scaffolds in recent years. In this study, the research of the mechanical properties and porosity of the fused TPMS porous bone scaffold provides us with a predictive tool to assist the design of the bone scaffold. First, porous bone scaffold models are established by fusing two different TPMS units, and the samples are manufactured by selective laser melting technology and subjected to quasi-static compression test. The response surface method is used to analyze the effects of TPMS unit constants K-1, K-2,K- and fused boundary r on the mechanical properties and porosity of the porous scaffold, and the optimal structural parameters of multiple response targets are obtained by optimization. The results show that the most ideal design parameters are K-1 = 10.000, K-2 = 2.656, r = 5.564, and the yield strength of the fused porous structure is 400.962 Mpa, the elastic modulus is 10.532 GPa, and the porosity is 64.027%, the error between the optimized result and the predicted result is very small. In summary, the porous bone scaffold with high yield strength and low elastic modulus is manufactured by fusion of TPMS, which provides an effective method for the application of bone substitutes.