摘要目的 评价三维打印成型技术(3DP)用于多孔钛植入体制备的可行性,研究不同烧结温度对其组织结构和力学性能的影响.方法 设计试件大小为25×20 mm圆柱体,设定每层的黏结面积为80％.选择纯度98.5％、颗粒直径约75 μm的钛粉为原料,聚乙烯醇粉作为黏结剂,聚乙烯吡咯烷酮粉作为辅助黏结剂.通过三维打印获得多孔钛植入体试件初胚,在氩气保护下,将试件分别烧结至1 200、1 300、1 400℃；对烧结完成的试件进行性能检测,包括孔隙率、显微硬度、扫描电镜观察试件的显微结构、抗压强度及弹性模量.结果 最终获得的多孔钛植入体试件,其收缩均匀、无明显变形、细节清晰、肉眼可见排列整齐的微孔结构、表面无裂纹,呈现金属光泽.在1 200、1 300、1 400℃的烧结温度下,孔隙率分别为(65.01±1.03)％、(46.73±0.73)％、(41.06±0.31)％,显微硬度为115.2±0.6、148.6±1.1、182.8±2.1,弹性模量为(5.9±0.5)、(16.2±0.9)、(34.8±1.5) GPa,抗压强度为(81.3±4.3)、(135.4±8.5)、(218.6±7.1)MPa.扫描电镜观察其孔隙相互连通成三维网状结构.结论 证实了应用三维打印成型技术制备多孔钛植入体的可行性,得到的多孔钛植入体具有与骨组织相匹配的良好的生物力学相容性.

abstractsObjective The aim of this study was to evaluate the feasibility of three-dimensional printing (3DP) for the preparation of porous titanium implant and to investigate the impacts on microstructure and mechanical properties with different sintering temperatures.Methods The CAD model of the specimens was designed to be 25 mm in diameter,20 mm in height,and with 0.5 mm pore size mesh.On every cross-section,80％ bonding area was designed.Titanium powder (purity of 98.5％,75 μm diameter) was selected as raw material.Polyvinyl alcohol powder (160 μm diameter) was selected as a binder,and polyvinylpyrrolidone powder was selected as an auxiliary binder.The green porous titanium implants were fabricated by 3DP followed by sintering at 1 200,1 300,1 400 ℃,separately,under the protection of argon gas.After sintering,the properties of porous titanium implants were evaluated,including the porosity,microstructure,microhardness,compressive strength and elastic modulus.Results After sintering,the specimen had uniform contraction and no obvious distortion.The specimen sintered at 1 200,1 300 and 1 400 ℃ sintering temperatures had porosity of (65.01±1.03)％,(46.73±0.73)％ and (41.06±0.31)％,hardness of 115.2±0.6,148.6±1.1 and 182.8±2.1,elastic modulus of (5.9±0.5),(16.2±0.9) and (34.8±1.5) GPa,compressive strength of (81.3±4.3),(135.4±8.5) and (218.6±7.1) MPa,respectively.A porous structure with three-dimensional network of connected pores was observed under scanning electron microscope.Conclusion It is feasible to fabricate porous titanium implants by three dimensional printing technique.The mechanical properties of the porous titanium implants match well with bone tissue which has excellent biomechanical compatibility.