微纳尺度HA陶瓷的显微硬度与断裂韧性研究

Study on microhardness and fracture toughness of micro-nano scale HA ceramics

本文用化学沉淀法制备HA-NPs,以制备的HA-NPs为原料采用粉末烧结法制备微纳尺度HA陶瓷材料;利用扫描电子显微镜、EBSD和显微硬度计,研究微纳尺度HA陶瓷材料的显微组织结构,显微硬度和断裂韧性,探究烧结工艺参数对材料显微组织结构及力学性能的影响规律。研究结果表明:基于响应面法建立了烧结温度和烧结时间与材料的显微硬度的二次回归模型。经方差分析,证明了所构建的模型具有良好的拟合效果,可用于材料显微硬度的预测及工艺参数的优化。HA陶瓷材料具有较高的脆性,在断裂过程中几乎无塑性变形。断裂韧性在实验设计参数范围内介于0.90~1.15 MPa·m^(0.5)之间。断裂韧性随HA晶粒尺寸的增加呈先升后降的趋势。

In this work,HA-NPs were prepared by a chemical precipitation method,and micro-nano HA ceramic materials were prepared by a powder sintering method using the prepared HA-NPs as raw materials.Scanning electron microscope(SEM),EBSD and micro-hardness tester were used to study the microstructure,micro-hardness and fracture toughness of HA ceramics to explore the influence of sintering process parameters on the microstructure and mechanical properties of the materials.The results show that the quadratic regression model of sintering temperature,sintering time and micro-hardness is established based on response surface method.The variance analysis proves that the model has good fitting effect and can be used to predict the micro-hardness of materials and optimize the process parameters.HA ceramics have high brittleness and almost no plastic deformation during fracture.The fracture toughness ranges from 0.90-1.15 MPa·m^(0.5)within the experimental design parameters.The fracture toughness increases first and then decreases with the increase of HA grain size.