HA-316L不锈钢纤维非对称功能梯度生物材料制备与显微组织

用低压热等静压方法在1100℃下制备了HA(ZrO₂)-316L不锈钢纤维非对称FGM,其中316L不锈钢纤维含量按体积比20%→15%→10%→5%呈非对称梯度变化.并通过金相显微镜、SEM、EDXA分析了材料的微观结构和微区元素含量.结果表明,HA(ZrO₂)-316L不锈钢纤维非对称FGM微观上表现为316L不锈钢纤维在FGM中呈无序、均匀分布状态,316L不锈钢纤维包裹于HA(ZrO₂)基体中,两者结合紧密,界面表现为部分凹凸不平,316L不锈钢纤维与HA(ZrO₂)基体紧紧的咬合在一起.在FGM基体中发生了微量的韧化相Fe元素扩散,韧化相316L不锈钢纤维不发生基体相Ca、P元素的扩散,基体与韧化相均相对独立,二者之间不发生任何化学反应.随着HA含量增加,HA(ZrO₂)-316L不锈钢纤维复合材料的断裂韧性和弹性模量逐渐减小,体现了FGM中各梯度层的力学性能缓和设计.HA(ZrO₂)-316L不锈钢纤维FGM中,分析认为,增韧机理主要为纤维拔出增韧和层间裂纹偏转增韧.

Preparation and Microstructure of HA-316L Stainless Steel Fibre Asymmetrical Functionally Graded Biomaterial

HA(ZrO₂)-316L stainless steel fibre asymmetrical functionally gradient biomaterial(FGM) was successfully fabricated under 1100℃ by low pressure hot isostatic pressing(HIP) technique. Metallographical microscope, SEM, EDXA analysis were carried out to examine the microstructure and elemental contents of the asymmetrical FGM. The results show that asymmetrical stepwise change of volume ratio of 316L stainless steel fibre according to 20%→15%→10%→5% can be corresponded in the FGM. 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 of 316L stainless steel fibre and HA(ZrO₂) matrix is partly concavo-convex. The approach also indicates that some Fe element diffusion of the toughing phase takes place in the HA(ZrO₂) matrix and no Ca, P element diffusion of the matrix takes place in 316L stainless steel fibre toughing phase. Both matrix and toughing phase are relatively independent and no chemical reaction is observed in the FGM. With the increase of HA contents, both fracture toughness and Young’s modulus of HA(ZrO₂)-316L stainless steel fibre composites are gradually reduced, which leads to mechanical properties relaxation design of the FGM. It is suggested that fibre pulling out and interbedded crack deflexion are the major toughing mechanism in the asymmetrical FGM.