SLA打印制备融合TPMS氧化铝陶瓷支架结构优化设计研究

Structure Optimal Design of Fusion TPMS Alumina Ceramic Scaffold Prepared by SLA Printing

三周期最小表面(TPMS)结构具有优异的力学性能与生物医学性能,设计制造合适的TPMS骨支架结构能为骨修复、骨替代、骨愈合的临床治疗提供可能。本文基于人体骨组织结构参数分别设计了以P、G、D三种类型为主的TPMS支架及其不同融合系数K值影响下的融合TPMS支架,采用紫外立体光刻技术(SLA)打印制备了陶瓷生坯,通过脱脂与烧结后处理获得了成型氧化铝陶瓷支架,并对支架模型与成型陶瓷试样分别进行了有限元仿真与实验测试。结果表明:1)陶瓷支架具有相对光滑的表面与较高的成型精度,其整体形态与设计模型基本一致,侧面比顶面稍显粗糙。2)与单类型结构相比,融合TPMS结构支架表现出较好的抗压强度与应力分布。其中,当融合系数K=4时,P与G结构融合支架支架的力学性能最优,抗压强度为71.72 MPa,最大应力与平均应力分别为141.90和13.214 MPa;3)融合结构的渗透性均弱于单类型结构,且不同融合系数K值的结构支架渗透性也不同,结合数值模拟与实验数据,当融合系数K=1、2时,P与G结构、P与D结构融合支架渗透性表现较好。综上,当融合系数K=1时,P与G结构融合支架同时具备较优的力学性能和渗透性,适合作为人体骨支架结构类型。

The three-cycle minimum surface(TPMS)structure has excellent mechanical and biomedical properties.By designing and manufacturing suitable TPMS bone scaffold structure,it provides the possibility for the clinical treatment of bone repair,bone replacement and bone healing.Based on the structure parameters of human bone tissue,TPMS scaffolds with three main types of P,G and D and the fusion TPMS scaffolds with different fusion coefficient K values were designed respectively.The ceramic billets were prepared by UV stereophotolithography(SLA),and the molded alumina ceramic scaffolds were obtained through degrease and post-sintering treatment.The results show that:1)the ceramic bracket has a relatively smooth surface and high molding accuracy,and its overall shape is basically consistent with the design model,and the side surface is slightly rougher than the top surface.2)Compared with the single-type structure,the fused TPMS structure shows better compressive strength and stress distribution.When the fusion coefficient K=4,the mechanical properties of the P and G fusion scaffold are the best,the compressive strength is 71.72 MPa,and the maximum stress and average stress are 141.90 and 13.214 MPa,respectively.3)The permeability of fusion structures is weaker than that of single-type structures,and the permeability of scaffolds with different fusion coefficient K values is also different.Combined with numerical simulation and experimental data,when the fusion coefficient K=1 or 2,the permeability of scaffolds with P and G structures and P and D structures is better.In conclusion,when the fusion coefficient K=1,the fusion scaffold with P and G structure has better mechanical properties and permeability,so it is suitable for the structure type of human bone scaffold.