Department of Mechanical and Industrial Engineering, Ryerson University, 350 Victoria Street, Toronto, Ontario M5B 2K3, Canada.
Biomaterials. 2010 Mar;31(7):1493-501. doi: 10.1016/j.biomaterials.2009.11.046. Epub 2009 Dec 1.
Pure hydroxyapatite (HA) is brittle and it cannot be directly used for the load-bearing biomedical applications. The purpose of this investigation was to develop a new iron-containing HA/titanium composite via pressureless sintering at a relatively low temperature with particular emphasis on identifying the underlying toughening mechanisms. The addition of iron to HA/titanium composites led to a unique and favorable core/shell microstructure of Ti-Fe particles that consisted of outer titanium and inner iron, and good interfacial bonding with HA matrix. While the relative density, hardness and Young's modulus reduced, the flexural strength, fracture toughness, fatigue resistance, and the related fracture surface roughness increased significantly with increasing amount of Ti-Fe particles. Different toughening mechanisms including crack bridging, branching and deflection were observed in the composites, thus effectively increasing the crack propagation resistance and resulting in a substantial improvement in the mechanical properties of the composites.
纯羟基磷灰石（HA）是脆性的，不能直接用于承重的生物医学应用。本研究的目的是通过在相对较低的温度下无压烧结开发一种新型含铁 HA/钛复合材料，特别强调确定潜在的增韧机制。在 HA/钛复合材料中添加铁会导致 Ti-Fe 颗粒具有独特且有利的核/壳微观结构，该微观结构由外层钛和内层铁组成，并与 HA 基体具有良好的界面结合。虽然相对密度、硬度和杨氏模量降低，但随着 Ti-Fe 颗粒含量的增加，弯曲强度、断裂韧性、耐疲劳性和相关的断裂表面粗糙度显著增加。在复合材料中观察到不同的增韧机制，包括裂纹桥接、分支和偏转，从而有效提高了裂纹扩展阻力，复合材料的力学性能得到了显著提高。
