【摘要】 采用Rhino软件构建孔隙率沿轴向与径向梯度变化的片状（Sheet型）三周期极小曲面（TPMS）-螺旋二十四面体（Gyroid）多孔结构（简称为轴向梯度多孔结构和径向梯度多孔结构），平均孔隙率在45%～85%，采用Ansys Workbench与Fluent软件对不同结构的压缩性能和渗透性能进行仿真，并与孔隙率均匀分布的均匀多孔结构（TG结构）进行对比；以TC4钛合金粉末为原料，采用选区激光熔化（SLM）技术打印出上述3种结构件，研究不同孔隙率结构件的压缩性能和渗透性能，并将试验结果与仿真结果进行对比。结果表明：仿真得到在相同平均孔隙率下轴向梯度和径向梯度多孔结构的等效弹性模量与平均应力均小于均匀多孔结构；径向梯度多孔结构的平均应力和等效弹性模量更接近于均匀多孔结构，且平均孔隙率越小，二者越接近于均匀多孔结构。2种梯度多孔结构的流体压力与速度分布与均匀多孔结构类似，但梯度多孔结构的流体速度更高；在平均孔隙率为85%时，径向梯度多孔结构的渗透率大于轴向梯度多孔结构和均匀多孔结构。试验得到3种SLM成形TC4钛合金结构件的弹性模量和抗压强度均在天然人体骨植入物的要求范围内，其中均匀多孔结构的压缩性能最好，径向梯度多孔结构的抗压强度和弹性模量更接近于均匀多孔结构；弹性模量和抗压强度随孔隙率的变化趋势与仿真等效弹性模量和平均应力的变化趋势相同，压缩初始断裂处与仿真的应力集中位置基本一致，验证了仿真结果的可靠性；在压缩过程中梯度多孔结构的应力波动较为剧烈，吸能特性较优异。径向梯度多孔结构更适合作为人体骨植入物。更多还原

【Abstract】 The sheet-like(Sheet type) triperiodic minimal surface(TPMS)-spiral eicosahedral(Gyroid) porous structures with porosity gradient variation along the axial and radial directions(called axial gradient porous structure and radial gradient porous structure) were constructed by Rhino software; the average porosities were 45%-85%. The compression properties and permeability of different structures were simulated by Ansys Workbench and Fluent software,and were compared with those of the uniform porous structure(TG structure) with uniformly distributed porosity. With TC4 titanium alloy powder as raw material,the above three structure parts were printed by selective laser melting(SLM)technique. The compression properties and permeability of different structure parts with different porosities were studied,and the test results were compared with the simulation. The results show that the equivalent elastic modulus and average stress of axial gradient and radial gradient porous structures were smaller than those of the uniform porous structure under the same average porosity by simulation. The average stress and equivalent elastic modulus of radial gradient porous structure were closer to those of the uniform porous structure,and the smaller the average porosity,the closer to those of the uniform porous structure. The fluid pressure and velocity distributions of the two gradient porous structures were similar to those of the uniform porous structure,but gradient porous structures had higher fluid velocities. At an average porosity of85%,the permeability of the radial gradient porous structure was larger than that of the axial gradient porous structure and the uniform porous structure. The elastic modulus and compressive strength of the three types of SLM-formed TC4 alloy structure parts by tests were within the required range for natural human bone implants. The compression properties of the uniform porous structure was the best, and the compressive strength and elastic modulus of the radial gradient porous structure were closer to those of the uniform porous structure. The variation trends of elastic modulus and compressive strength with the porosity were the same as those of the simulated equivalent elastic modulus and average stress,and the initial fracture points were basically consistent with the stress concentration positions in the simulation, verifying the reliability of the simulation. The stress fluctuation of the gradient porous structure was more intense during the compression,and the energy-absorbing property was more excellent. The radial gradient porous structure was more suitable for human bone implants.更多还原