(哈尔滨工业大学材料科学与工程学院，哈尔滨 150001
*东南大学分析测试中心，南京 210018)
摘 要: 用粉末冶金法制备出HA-Ti/Ti/HA-Ti轴对称生物功能材料(FGM)，并测定了HA-Ti复合体材料的力学性能和热膨胀系数。应用经典叠层板理论和热弹性力学理论分析了HA40-Ti/Ti/H A40-Ti直接叠层体和轴对称FGM制备残余热应力。结果表明其微观组织呈对称型梯度化分布。FGM中间纯Ti层具有最高的抗弯强度和断裂韧性(分别为971.96 MPa和29.691 MPa·m1/2)，而表面层的弹性模量最低，只有87.71GPa。从生物医学应用的角度看，力学性能如此分布的生物材料正是我们所期望的。其热膨胀系数随着HA含量和温度的升高而增大。制备残余热应力强烈依赖于组成分布，组成对称梯度化分布导致了FGM中残余热应力也呈现对称梯度化分布，并降低了其表面层制备残余拉应力。
关键字: 功能梯度材料 生物材料 热应力缓和 轴对称
（School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, P. R. China
*Analysis and Testing Center, Southeast University, Nanjing 210018, P. R. China）
Abstract:The hydroxyapatite(HA)-Ti/Ti/HA-Ti axial symmetrical functionally graded biomaterial (FGM) has been developed by powder metallurgical process. Mechanical properties and thermal expansion coefficient of HA-Ti composite materials were investigated. The residual thermal stress in axial symmetrical FGM and HA40-Ti/Ti/HA40-Ti non-FGM plate cooled to room temperature after sintering has been analyzed by the classical lamination theory and thermal-elastic mechanics. The results showed that the microstructure of FGM displays a symmetrical graded distribution; the middle pure Ti layer in FGM has the maximal bending strength and fracture toughness(971.96 MPa and 29.69 MPa·m1/2 respectively), while the Young's modulus of surface layer (only 87.71 GPa) is minimal, the biomaterial with such a distribution of mechanical properties is expected from the viewpoint of bio-applications. The thermal expansion coefficient increases with the rise of the testing temperature and HA content; the residual thermal stress strongly depends on the constitutional distribution. The graded distribution of the compositions results in the decrease of residual tensile stress in surface layer. The residual thermal stress in FGM exhibits the axial symmetrical graded distribution as the compositions .
Key words: functionally graded material; biomaterial; thermal stress relaxation; axial symmetrical
