凝胶注模成型技术制备氧化石墨烯/HA复合材料的研究

以氧化石墨烯和纳米羟基磷灰石(HA)粉体为原料,采用凝胶注模成型技术制备了氧化石墨烯/HA复合材料。研究了有机单体、浆料固相含量和石墨烯含量对氧化石墨烯/HA浆料粘度的影响,观察了陶瓷浆料的凝胶固化过程并测量了固化后生坯的密度和抗压强度,分析了氧化石墨烯含量对烧结后复合材料抗弯强度和断裂韧性的影响,观察了试样断口的显微组织。研究结果表明,有机单体含量为15%(质量分数,下同),固相含量为45%,氧化石墨烯含量为1.5%时,氧化石墨烯/HA浆料的粘度最佳,为362.9mPa·s,浆料的分散性良好,固化后生坯具有较高的密度和抗压强度。随氧化石墨烯含量的增加,复合材料的抗弯强度和断裂韧度均先增加后降低。当氧化石墨烯含量为1.5%时,1 150℃烧结样品的抗弯强度为81.5MPa,断裂韧性为1.52MPa·m1/2,分别比HA基体提高了151.8%和74.7%,因此添加氧化石墨烯后的HA复合材料的力学性能更佳。

Study on Graphene Oxide/HA Composites Prepared by Gelcasting Technology

Graphene oxide (GO) and hydroxyapatite(HA) particles were used as initial materials to prepare GO/HA composites by gelcasting method.The effects of the contents of organic monomer and graphene oxide,the solid content of the slurries on viscosity of GO/HA slurries were studied.The gelcasting processes of the GO/HA slurries were observed and the green density and compressive strength of green compacts were measured.The effects of GO contents on bending strength and fracture toughness of GO/HA composites were analyzed.The microstructure of the fracture surface of the HA composites were observed.The results show that at organic monomer of 15wt％,GO particles of 1.5wt％ and the solid content of slurries of 45wt％,the GO/HA slurries have better viscosity of 362.9 mPa · s and good dispersion.The solidified compacts have better density and compressive strength.With the increase of the contents of the GO particles,the bending strength and fracture toughness of the HA composites first increase and then decrease.When the content of GO particles is 1.5wt％,the GO/HA composites sintered at 1 150 ℃ have bending strength of 81.5 MPa and flexural toughness of 1.52 MPa · m1/2,which are 151.8％ and 74.7％ higher than those of HA matrix.Therefore,the GO/HA composites have better mechanical properties with the addition of GO particles.