HA(ZrO_(2))/316L不锈钢纤维对称功能梯度生物材料

Researches on HA(ZrO_2)/316L stainless steel fibre symmetrical functionally graded biomaterial

制备了HA(ZrO2)/316L不锈钢纤维对称功能梯度材料(FGM),316L不锈钢纤维的含量(体积分数)按20%→10%→0→10%→20%呈轴向对称梯度变化.分析了材料的微观结构和微区元素含量,研究了材料的性能与316L不锈钢纤维含量的关系.结果表明,在HA(ZrO2)/316L不锈钢纤维对称FGM中,316L不锈钢纤维在微观上呈无序和均匀分布状态,它被包裹于HA(ZrO2)基体中,两者紧密结合.316L不锈钢纤维与HA(ZrO2)基体间的界面表现为部分凹凸不平,紧紧地咬合在一起.在FGM基体中发生了微量的韧化相Fe元素扩散,在韧化相316L不锈钢纤维不发生基体相Ca、P元素的扩散,基体与韧化相之间不发生化学反应.随着316L不锈钢纤维含量的增加,HA(ZrO2)/316L不锈钢纤维复合材料的断裂韧性和弹性模量逐渐增加,体现了FGM中各梯度层的力学性能缓和设计.按Miao模型计算HA(ZrO2)/316L不锈钢纤维FGM中的残余热应力为515MPa,FGM的增韧机理主要为纤维的拔出增韧和层间的裂纹偏转增韧.

HA(ZrO2)/316L stainless steel fibre symmetrical functionally graded biomaterial (FGM) was successfully fabricated at 1100°C using low pressure hot isostatic pressing (HIP) technique, whereas axial stepwise change of volume fraction of 316L stainless steel fibre according to 20%&rarr10%&rarr0&rarr10%&rarr20% can be corresponded in the FGM. The results show that 316L stainless steel fibre is randomly and evenly distributed in the FGM. 316L stainless steel fibre is enwrapped in the HA(ZrO2) matrix and both integrate each other tightly. The interface between 316L stainless steel fibre and HA (ZrO2) matrix is partly concavo-convex. Some Fe element diffusion of the toughing phase takes place in the HA(ZrO2) matrix. No chemical reaction is observed in the FGM. With the increase of contents of 316L stainless steel fibre, both fracture toughness and Young's modulus of HA(ZrO2)/316L stainless steel fibre composites increase gradually, which results in mechanical properties relaxation design of the FGM. Furthermore, residual thermal stress in the FGM can be calculated as 515 MPa on the ground of Miao model. The fibre pulling out and interbedded crack deflexion are the major toughing mechanism in the symmetrical FGM.