Ti35Nb7Zr-xHA生物复合材料的微观组织与性能研究

Research on Microstructure and Properties of Ti35Nb7Zr-xHA Biocomposites

为了改善Ti-Nb-Zr合金的生物活性,采用放电等离子烧结(SPS)技术制备了不同羟基磷灰石(HA)含量的Ti35Nb7Zr-xHA(x=0、5、10、20(质量分数,%))生物复合材料,研究了HA含量对复合材料微观组织、力学性能及体外生物活性的影响。结果表明,复合材料主要由β-Ti、α-Ti、HA及陶瓷相(Ti_xP_y、CaTiO_3、Ti_2O、CaO)组成;HA含量增加会导致β-Ti减少而α-Ti和陶瓷相明显增多;与Ti-35Nb-7Zr合金(E:45GPa,σ:1 736 MPa)相比,HA含量为5%和10%时,复合材料的抗压强度分别为1 662MPa和1 593MPa,弹性模量分别为48GPa和49GPa,综合力学性能与Ti-35Nb-7Zr合金接近,展现出良好的力学性能,而过高的HA含量(20%)会导致复合材料弹性模量明显升高(E:55GPa)、抗压强度急剧下降(σ:958 MPa),复合材料的力学性能降低;体外生物活性实验表明,加入10%HA的复合材料在人工模拟体液(SBF)中浸泡7d后表面生成了大量的类骨磷灰石层,与Ti-35Nb-7Zr合金相比,其显示出更优异的体外生物活性。

To improve the bioactivity of Ti-Nb-Zr alloy,Ti35Nb7Zr-xHA biocomposites with different hydroxyapatite（HA）contents（x=0,5,10,20（mass fraction,%））were prepared by spark plasma sintering（SPS）technique.The effects of HA contents on microstructure,mechanical properties and in vitro bioactivity of the composites were investigated.The results show that the composites are mainly consisted ofβ-Ti phase,α-Ti phase,HA and metal-ceramic phases（Ti_xP_y,CaTiO_3,Ti_2O,CaO）.With the increase of the HA content,theβ-Ti phase decrease,while theα-Ti phase and metal-ceramic phase increase obviously.Compared to Ti-35Nb-7Zr alloy（E：45GPa,σ：1 736MPa）,the compressive strength and the elastic modulus of Ti35Nb7Zr-xHA composites（x=5,10）are in range of 1 593—1 662 MPa and 48—49 GPa,respectively,which are close to those of Ti-35Nb-7Zr alloy,and presenting agood mechanical properties.However,the Ti35Nb7Zr-20HA composite has highest elastic modulus（E：55GPa）and lowest compressive strength（σ：958MPa）compared with other composites,presenting poor mechanical property.Furthermore,lots of bone-like apatite is deposited on the surface of Ti35Nb7Zr-10HA composite after soaking in SBF for 7dvia in vitro bioactivity experiments,the Ti35Nb7Zr-10HA presents an excellent bioactivity compared with the Ti-35Nb-7Zr alloy.