三维打印制备钛/羟基磷灰石复合体及功能梯度材料

Three-dimensional printing of titanium/hydroxyapatite composite and functionally graded materials

背景:传统压模成形法制备的钛/羟基磷灰石复合材料结构简单,自动化程度较低,难以控制材料的孔隙率及孔径,不能满足多样化需求。目的:评价三维打印成型技术制备钛/羟基磷灰石复合体及功能梯度材料的可行性。方法:设计钛/羟基磷灰石复合体为直径25mm、高度15mm的圆柱体,功能梯度材料为直径25mm,上层5mm的钛粉末层,下层5mm钛/羟基磷灰石粉末层的圆柱体CAD模型。利用三维打印技术制备钛/羟基磷灰石复合体及功能梯度材料并进行烧结。观察烧结完成后钛/羟基磷灰石复合体和钛/羟基磷灰石功能梯度材料的显微结构,并行X射线衍射分析和抗压强度检测。结果与结论:烧结后的钛/羟基磷灰石复合体及功能梯度材料试件均匀无收缩和变形。钛/羟基磷灰石复合体形成紧密结晶体,孔径为50-150μm。钛和羟基磷灰石在烧结中发生了化学反应,生成物包含Ca3(PO4)2、CaTiO3、TiO2和CaO,其抗压强度为(184.3±27.1)MPa。烧结后钛/羟基磷灰石功能梯度材料在微观结构下可见不同材料间较为清晰的分界线,具有梯度结构。表明三维打印技术制备钛/羟基磷灰石复合体及功能梯度材料的微观结构和力学性能可满足医用生物植入材料的要求。

BACKGROUND：Preparation of titanium/hydroxyapatite composite by conventional methods has the deficiency of simple structure, low degree of automation and difficulty in porosity and pore size control, which limits the diverse process and manufacture. OBJECTIVE：To evaluate the feasibility of three-dimensional printing technology for the preparation of titanium/hydroxyapatite composite and titanium/hydroxyapatite functional y graded material molding. METHODS：A CAD model of titanium/hydroxyapatite composite was designed to be the cylinder （diameter 25 mm, height 20 mm）, while the titanium/hydroxyapatite functional y graded implant designed as a CAD model of the cylinder with 25 mm in diameter asnd 10 mm in height with two layers, the upper layer with titanium powder and the lower layer with titanium/hydroxyapatite powder. The composite and functional y graded implant were processed by the three-dimensional printing and sintered. The sintered titanium/hydroxyapatite composite and titanium/hydroxyapatite functional y graded implant were observed for their microstructures, and the X-ray diffraction analysis and compressive strength testing were performed. RESULTS AND CONCLUSION：The sintered titanium/hydroxyapatite composite and titanium/hydroxyapatite functional y graded implant had uniform contraction and no obvious distortion. The sintered titanium/hydroxyapatite composite had the aperture size from 50 to 150μm. There occurred a chemical reaction between titanium and hydroxyapatite during the sintering process, obtaining the new creations of Ca3（PO4）2, CaTiO3, TiO2 and CaO. Its compressive strength was （184.3±27.1） MPa. The microstructure of titanium/hydroxyapatite functional y graded implant had graded structures with a visible line between the two layers. The results of the microstructure and mechanical properties of titanium/hydroxyapatite composite and titanium/hydroxyapatite functional y graded implant can meet the requirements of medical biological implant materials.