制备与表征
(中南大学 粉末冶金国家重点实验室, 长沙 410083)
摘 要: 采用干粉铺叠法和热压工艺制备了非对称HA/316L不锈钢功能梯度生物材料， 并测定了其相对密度和抗弯强度， 采用X射线衍射仪、 扫描电镜、 金相显微分析技术等对材料进行了物相和显微组织分析。 结果表明： 非对称HA-316L不锈钢生物FGM在宏观上呈现明显的梯度分布， 微观上则各成分分布连续、 均匀， 各梯度层之间没有明显的宏观界面， 界面结合紧密； 随着316L不锈钢含量的增大， 材料的相对密度增加，抗弯强度提高， 平均抗弯强度达450 MPa左右， 体现出FGM的热应力缓和行为；此外， 在生物FGM中， HA和316L不锈钢两相在热压过程中发生了不同程度的固溶，表明HA和316L不锈钢能够形成好的结合。
关键字: 316L不锈钢；羟基磷灰石； 生物材料； 功能梯度材料； 热压
asymmetrical HA/316L SS functionally
gradient biomaterial
（State Key Laboratory for Powder Metallurgy,
Central South University, Changsha 410083, China）
Abstract: Functionally gradient biomaterial of asymmetrical HA/316L stainless steel was prepared by hot pressing technology. The relative density and bending strength of these functionally gradient biomaterials were determined, and their phase analysis and microstructure were also examined by using X-ray diffractrometry, scanning electron microscope and metallographic analysis technology. The experimental results show that the biological FGM of asymmetrical HA-316L had obvious gradient on the macroscopic, while each component was distributed continuously and evenly. There was no obvious microscopical interface between each gradient layer, and the interface was combined closely. With the increase of the content of the 316L stainless steel, the relative density of the biomaterial was increased, the bending strength was improved, and the average bending strength was about 450 MPa. So that thermal stress relaxation of the FGM could be indicated. In addition, the two phases of HA and 316L stainless steel diffused in each other in some degree during hot pressing, indicating that HA and 316L stainless steel could combine firmly.
Key words: 316L stainless steel powder; hydroxyapatite (HA); biomaterial; functionally gradient material (FGM); hot pressing
