凝胶注模成型制备医用多孔钛植入材料及其性能

Fabrication and characterization of gelcasting porous titanium implants

应用一种新的近净成型技术——凝胶注模成型技术，成功制备大尺寸、复杂形状医用多孔钛人造骨替代材料，并研究了凝胶注模成型工艺参数对浆料流动特性、坯体强度及烧结体孔隙、力学性能的影响。研究结果表明：预混液中有机单体的浓度、单体／交联剂比例以及固相含量是决定钛粉浆料表观粘度、Gelcasting坯体强度的重要参数；对于医用多孔钛植入材料的凝胶注模成型工艺，适合的顸混液单体浓度为30％（质量分数），单体，交联剂比例为120：1，浆料固相含量为34％（体积分数）；1100℃保温1．5h是凝胶注模成型多孔钛较为适合的烧结工艺路线；所制得孔隙度46．5％、开孔隙度40．7％多孔钛的抗压强度158．6MPa、弹性模量8．5GPa，与自然骨基本匹配，适合作为人造骨替代材料。

A novel near-net forming process, gelcasting, was successfully used to prepare porous titanium implants with large-size and complex-shape, and the effects of processing parameters on the viscosity of the slurry, dry green strength, porosity and mechanical properties of sintered body were investigated. Experimental results show that monomer content and the ratio of monomer to cross-linker in premixed solution, and solid loading of the slurry can affect apparent viscosity of the slurry and green strength. In gelcasting process of porous titanium implants, the optimum amounts of above-mentioned parameters are 30 wt. %, 120： 1 and 34 vol. % respectively. Moreover, the proper sintering process of gelcasting porous titanium is at 1373K for 1.5h, at which, the total porosity and open porosity of porous titanium were 46.5% and 40.7% respectively, and its mechanical properties are compressive strength 158.6MPa, Elastic modulus 8.5GPa, similar to those of human cortical bone and appropriate for implanting purpose.