激光选区熔化成型CoCrMo多孔结构的设计与性能研究

Study on Design and Properties of Porous CoCrMo Alloy Structure Manufactured by Selective Laser Melting

为获得具备良好力学性能和生物相容性的多孔植入体,需对激光选区熔化（SLM）成型Co Cr Mo多孔结构进行性能分析。在电子万能试验机上沿零件加工的纵向进行压缩试验,应用分形插值理论分析相关参数对其压缩性能的影响。试验结果表明：变形主要以滑移为主;弹性模量和抗压强度随着孔隙率和平均孔径的增大而减小,随表面积体积比的增大而增大。正八面体和正六面体多孔结构孔隙率为55%~84%,平均孔径为0.51~0.99 mm,表面积体积比为2~4.2时,弹性模量都能满足要求。正八面体圆柱形多孔结构的性能比方形结构更加优越,正六面体方形结构的性能比圆柱形结构更好,为激光选区熔化成型多孔Co Cr Mo合金结构医学植入体的研制提供重要依据。

To obtain porous medical implants with excellent mechanical properties and biocompatibility, compression performance analysis of CoCrMo alloy parts manufactured by selective laser melting （SLM） is performed. Compression experiments are conducted on the electronic universal testing machine along longitudinal direction, in which the CoCrMo alloy parts are made and fractal interpolation theory is used to analyze the influence caused by relevant parameters on compression performance. The experiment results show that the main deformation is slippage. Both of the elastic modulus and the compressive strength decrease with increasing porosity and average pore size, while decrease with the reduction of surface area to volume ratio. When the regular octahedral and regular hexahedral porous structures are with porosity in the range of 55%-84%, average pore size of 0.51-0.99 mm, and surface area to volume ratio from 2 to 4.2, the elastic modulus will meet the requirement. Regular octahedral cylindrical porous structures have better performance than the square structures, but regular hexahedral square porous structures have better performance than the cylindrical structures. The conclusions above provide important basis for selective laser melting process of porous CoCrMo alloy structures used as medical implants.