医用钛合金微弧氧化复合陶瓷膜层断裂力学研究

Fracture Mechanics of Composite Ceramic Coating Prepared by Micro-arc Oxidation on Biomedical Titanium Alloy

以Ti6Al4V钛合金为基体材料,通过微弧氧化方法在电解液中制备多孔氧化锆和羟基磷灰石复合医用钛合金陶瓷膜层。利用能谱分析仪、扫描电镜和X-射线衍射仪分析膜层结构及相组成特点。对试样断裂韧性进行测量试验,通过测试结果对膜层断裂韧性进行了分析研究。探究了氧化锆对于钛合金羟基磷灰石膜层的增韧机制,并建立了适于多孔微裂纹膜层材料断裂韧性数学模型。结果表明,ZrO2/羟基磷灰石医用钛合金复合陶瓷膜层比单一的羟基磷灰石陶瓷膜层具有更好的断裂韧性。

In order to fabricate porosity medical coating on the titanium alloy surface,Ti6A14V were used as the matrix material and the complex ceramic coating of zirconia （ ZrO2 ）/bydroxyapatite were ultimately fabricated by Micro-arc oxidation in the electrolyte. The structure and morphology characteristics of coatings were analyzed by energy dispersive spectrometer （EDS）, scanning electron microscopy （SEM） and X-ray diffraction, respectively. Besides, the fracture toughness measure experiment was carried out, and the data were analyzed. And the fracture mechanics mathematical models were established at the same time. The experimental and calculated complex methods were researched for coating biomechanics properties. The results showed that the ZrO2/hydroxyapatite coatings exhibited better fracture toughness and biomechanical properties as compared to the individual hydroxyapatite coatings, which was attributed to the introduction of second phase toughening, phase transformation toughening and microcrack toughening. So it could be concluded that the toughening effect of ZrO2 was obvious and the established model was scientific and rational and had certain theoretical meanings.