Abstract
BACKGROUND:Machinable bioglass-ceramics became a new inorganic biomaterial; moreover, strength, toughness and machinability are significantly studied.

OBJECTIVE: To observe the effect of ZnO, Fe2O3 and ZrO2 additives on the microstructure and properties of machinable bioglass-ceramic in K2O-MgO-CaO-SiO2-P2O5-F system.

DESIGN: Observational contrast study.

SETTING: Department of Orthopaedics, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology.

MATERIALS: The experiment was carried out in the Laboratory of Materials, Wuhan University of Technology from October 2003 to April 2004. K2O-MgO-CaO-SiO2-P2O5-F system, ZnO, Fe2O3 and ZrO2 additives, D/Max-ⅢA X-ray diffractometer (Japan), JSM-5610LV scanning electron microscope (SEM), HVS-1000 microhardnessmeter and 3257-35 magnetic testing device (Japan) were used in this study.

METHODS: In the glass-ceramic of K2O-MgO-CaO-SiO2-P2O5-F system, three kinds of additives ZnO, ZnO-Fe2O3 and ZnO-Fe2O3-ZrO2 were added respectively. These three kinds of ceramics were prepared by being melted at 1 400 ℃ for 1 hour. After fire, crystal temperature was set based on differential thermal analysis curve. ① Physical properties: Microhardness was determined with microhardnessmeter (HVS-1000). The flexural strength and fracture toughness were established measured with ceramic mechanical test system (MTS) method and single edge notched beam (SENB) method, respectively. Saturation magnetic moment and Curie temperature were determined with 3257-35 magnetism test machine made in Japan. Holing method was used to measure machinability. ② Test of crystalline phase and microstructure: Crystalline phase analysis was carried out with X-ray diffraction (XRD: D/Max-ⅢA) and microstructure analysis were conducted on an etched fracture surface using SEM (JSM-5610LV, Japan).

MAIN OUTCOME MEASURES: Effects of ZnO, Fe2O3 and ZrO2 additives on physical properties, mineral composition and crystalline phase.

RESULTS: ① The addition of ZnO to the glass-ceramic in K2O-MgO-CaO-SiO2-P2O5-F system was beneficial to crystal growth, increasing aspect ratio of crystal, decreasing microhardness and improving toughness and machinability. ② The addition of ZnO-Fe2O3 to the glass-ceramic in K2O-MgO-CaO-SiO2-P2O5-F system can form minority Mg-Zn ferrite with magnetism. The main crystalline phase present in the glass- ceramic was diopside with small size and hardness was improved, which led to worse machinability. ③ Because of the addition of ZnO-Fe2O3-ZrO2, magnesia fluormica and fluorapatite became the main crystalline phases, and the minor phases including Mg-Zn ferrite, t-ZrO2 and m-ZrO2, etc. also presented in the glass-ceramic. This material possessed high strength and toughness, good machinability and magnetism, which could stimulate formation of new bone, and was good substitute of bone restorations. Bioassay and in vitro test indicated that the glass-ceramic in K2O-MgO-CaO-SiO2-P2O5-F system was bioactive and biocompatible.

CONCLUSION: ZnO, Fe2O3 and ZrO2 additives play a significant role in changing crystalline structure, enhancing strength, toughness and machinability of machinable bioglass-ceramic and generating magnetism.

1Department of Orthopedics, Beijing Jishuitan Hospital, Beijing 100035, China; 2School of Material Science and Engineering, Wuhan University of Technology, Wuhan 430070, Hubei Province, China; 3Department of Orthopedics, the Affiliated Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China

Zhou Xin-hua☆, Doctor, Attending physician, Department of Orthopedics, Beijing Jishuitan Hospital, Beijing 100035, China
bjzhouxinhua@sina.com

Received:2007-02-13
Accepted:2007-05-22 (06-50-2-1110/YWY)

Zhou XH, Chu Y, Chen AM, Sun SZ.Effect of additives on the microstructure of machinable bioglass-ceramic.Zhongguo Zuzhi Gongcheng Yanjiu yu Linchuang Kangfu 2007;11(22):4443-4446(China)

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zglckf/ejournal/
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22k-4443(ps).pdf]

添加剂对可切削生物微晶玻璃结构的影响☆

摘要
背景：医用可加工微晶玻璃是一种新型的无机生物新材料，可切削生物微晶玻璃的强度、韧性和可切削加工性能值得研究。
目的：分析ZnO、Fe2O3和ZrO2添加剂对 K2O-MgO-CaO-SiO2-P2O5-F系统可切削微晶玻璃的结构和性能的影响。
设计：观察对比实验。
单位：华中科技大学同济医学院附属同济医院骨科。
材料：实验于2003－10/2004－04在在武汉理工大学材料学院实验室完成。K2O-MgO-CaO-SiO2-P2O5-F系统及ZnO、Fe2O3和ZrO2添加剂，日本理学D/Max-ⅢA型X射线衍射仪及JSM-5610LV型扫描电镜，HVS-1000显微硬度计，日产3257-35磁性测试仪。
方法：采用K2O-MgO-CaO-SiO2-P2O5-F系统可切削生物微晶玻璃，分别加入适量的ZnO、ZnO-Fe2O3和ZnO-Fe2O3-ZrO2添加剂，在1 400 ℃下熔制，保温1 h，浇铸成型，经退火后根据差热分析曲线制定晶化温度制度，制备了3组不同组分的微晶玻璃。① 物理性能的测试：采用HVS-1000显微硬度计测定显微硬度、MTS陶瓷试验系统三点弯曲法及单面切口三点弯曲法测定抗弯强度和断裂韧性、日产3257-35磁性测试仪测定饱和磁矩及居里温度、钻孔法测定了可切削性。②矿物组成及晶体形貌的测定：采用日本理学D/Max-ⅢA型X射线衍射仪及JSM-5610LV型扫描电镜分别测定了3种试样的矿物组成及晶体的形貌。
主要观察指标：ZnO、ZnO-Fe2O3和ZnO-Fe2O3-ZrO2添加剂制备不同组分的微晶玻璃物理性能、矿物组成及晶体形貌的测定结果。
结果：① ZnO加入K2O-MgO-CaO-SiO2-P2O5-F微晶玻璃中，有利于晶体成长，增加晶体的长径比，显微硬度低，韧性较好，易于切削。②ZnO-Fe2O3加入K2O-MgO-CaO-SiO2-P2O5-F微晶玻璃中，形成少量镁锌铁尖晶石铁氧体，具有磁性。主晶相为透辉石，晶粒细小，硬度较大，切削性能下降。③ ZnO-Fe2O3-ZrO2加入K2O-MgO-CaO-SiO2-P2O5-F微晶玻璃中，析晶后主晶相为氟镁白云母、氟磷灰石，另有少量的镁锌铁尖晶石铁氧体、t-ZrO2、m-ZrO2等。材料强度高、韧性及可切削性能良好，具有的磁性能激发新骨形成，用其做骨替代材料可加速骨缺损的修复。
结论： ZnO、ZnO-Fe2O3和ZnO-Fe2O3-ZrO2添加剂的加入对改变生物微晶玻璃的晶体结构，提高生物微晶玻璃的强度、韧性和可切削性具有重要意义，并同时赋予了磁性。
关键词：添加剂；可切削生物微晶玻璃；显微结构

周新华1，褚 颖2，陈安民3，孙淑珍2
1北京积水潭医院矫形骨科，北京市 100035； 2武汉理工大学材料学院，湖北省武汉市 430070； 3华中科技大学同济医学院附属同济医院骨科，湖北省武汉市 430030
周新华☆，男，汉族，1967年生，湖北省黄梅县人，2004年华中科技大学同济医学院毕业，博士，主治医师，主要从事生物材料、人工关节的研究。

中图分类号:R318.08 文献标识码:A 文章编号:1673-8225(2007)22-04443-04
周新华，褚颖，陈安民，孙淑珍.添加剂对可切削生物微晶玻璃结构的影响[J].中国组织工程研究与临床康复，2007，11(22):4443-4446
[www.zglckf.com/zglckf/ejournal/upfiles/07-22/22k-4443(ps).pdf]