Lam Tu-Ngoc, Chen Kuang-Ming, Tsai Cheng-Hao, Tsai Pei-I, Wu Meng-Huang, Hsu Ching-Chi, Jain Jayant, Huang E-Wen
Department of Materials Science and Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan.
Department of Physics, College of Education, Can Tho University, Can Tho City 900000, Vietnam.
Materials (Basel). 2023 Jan 12;16(2):751. doi: 10.3390/ma16020751.
To minimize the stress shielding effect of metallic biomaterials in mimicking bone, the body-centered cubic (bcc) unit cell-based porous CoCrMo alloys with different, designed volume porosities of 20, 40, 60, and 80% were produced via a selective laser melting (SLM) process. A heat treatment process consisting of solution annealing and aging was applied to increase the volume fraction of an ε-hexagonal close-packed (hcp) structure for better mechanical response and stability. In the present study, we investigated the impact of different, designed volume porosities on the compressive mechanical properties in as-built and heat-treated CoCrMo alloys. The elastic modulus and yield strength in both conditions were dramatically decreased with increasing designed volume porosity. The elastic modulus and yield strength of the CoCrMo alloys with a designed volume porosity of 80% exhibited the closest match to those of bone tissue. Different strengthening mechanisms were quantified to determine their contributing roles to the measured yield strength in both conditions. The experimental results of the relative elastic modulus and yield strength were compared to the analytical and simulation modeling analyses. The Gibson-Ashby theoretical model was established to predict the deformation behaviors of the lattice CoCrMo structures.
为了在模拟骨骼时尽量减少金属生物材料的应力屏蔽效应，通过选择性激光熔化（SLM）工艺制备了具有20%、40%、60%和80%不同设计体积孔隙率的体心立方（bcc）晶胞基多孔CoCrMo合金。采用包括固溶退火和时效的热处理工艺来增加ε-六方密堆积（hcp）结构的体积分数，以获得更好的力学响应和稳定性。在本研究中，我们研究了不同设计体积孔隙率对铸态和热处理CoCrMo合金压缩力学性能的影响。随着设计体积孔隙率的增加，两种状态下的弹性模量和屈服强度均显著降低。设计体积孔隙率为80%的CoCrMo合金的弹性模量和屈服强度与骨组织的弹性模量和屈服强度最为接近。对不同的强化机制进行了量化，以确定它们在两种状态下对测量屈服强度的贡献作用。将相对弹性模量和屈服强度的实验结果与分析和模拟建模分析进行了比较。建立了Gibson-Ashby理论模型来预测晶格CoCrMo结构的变形行为。
