TZP增韧HA复合材料的电镜研究

用透射电子显微镜对四方氧化锆多晶（TZP）增韧羟基磷灰石（HA）复合材料的微观相结构进行了观察与分析。结果表明，氧化锆的加入没有改变羟基磷灰石的晶体结构，羟基磷灰石材料的生物活性没有降低。氧化锆以三种晶形存在，即单斜氧化锆、四方氧化锆和立方氧化锆。单斜氧化锆的出现说明材料内发生了四方氧化锆（t-ZrO2）向单斜氧化锆（m-ZrO2）马氏体相变，这种马氏体相变有利于提高HA材料的韧性。力学性能结果表明，加入ZrO2后，材料的断裂韧性明显提高。同时对TZP增韧HA材料的增韧机制进行了探讨，并认为ZrO2对HA材料的增韧机制主要是应力诱导相变增韧和相变诱发微裂纹增韧。

A TEM Study on the Bioactive Composites of Hydroxyapatite Reinforced by Tetragonal Zirconia Polycrystal

The microstructure and phases present in hydroxyapatite(HA) reinforced by tetragonal zirconia polycrystal (TZP) were investigated by using transmission electron microscopy(TEM). It was found that the crystal structure of HA was not changed by the composite_making process, thus the bioactivity of the composite was not degraded either; and that c _ZrO 2, t _ZrO 2 and m _ZrO 2 were all present in the composite, suggesting the occurrence of a martensitic phase transformation, which would have been responsible for the toughening of the TZP_reinforced HA composite. The toughening mechanism of ZrO 2_reinforced HA composite were stress_induced phase transformation toughening and phase transformation_induced micro_crack toughening.