(哈爾濱工業(yè)大學(xué)材料科學(xué)與工程學(xué)院，哈爾濱 150001
*東南大學(xué)分析測試中心，南京 210018)
摘 要: 用粉末冶金法制備出HA-Ti/Ti/HA-Ti軸對稱生物功能材料(FGM)，并測定了HA-Ti復(fù)合體材料的力學(xué)性能和熱膨脹系數(shù)。應(yīng)用經(jīng)典疊層板理論和熱彈性力學(xué)理論分析了HA40-Ti/Ti/H A40-Ti直接疊層體和軸對稱FGM制備殘余熱應(yīng)力。結(jié)果表明其微觀組織呈對稱型梯度化分布。FGM中間純Ti層具有最高的抗彎強度和斷裂韌性(分別為971.96 MPa和29.691 MPa·m1/2)，而表面層的彈性模量最低，只有87.71GPa。從生物醫(yī)學(xué)應(yīng)用的角度看，力學(xué)性能如此分布的生物材料正是我們所期望的。其熱膨脹系數(shù)隨著HA含量和溫度的升高而增大。制備殘余熱應(yīng)力強烈依賴于組成分布，組成對稱梯度化分布導(dǎo)致了FGM中殘余熱應(yīng)力也呈現(xiàn)對稱梯度化分布，并降低了其表面層制備殘余拉應(yīng)力。
關(guān)鍵字: 功能梯度材料 生物材料 熱應(yīng)力緩和 軸對稱
（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
