【作者】 李侠；

【导师】 钟涛兴；

【作者基本信息】 北京工业大学 ， 材料学， 2006， 硕士

【摘要】 随着CAD/CAM技术的不断进步和人们对于美学性能的更高追求,牙科可加工陶瓷材料越来越受患者的欢迎。目前已应用与临床的可加工长石瓷颜色与人体牙齿最为接近,可以再现自然牙齿的生动性。但长石瓷脆性大,断裂韧性低,临床失败率比较高。所以本论文利用SPS的特殊烧结机理提高长石瓷的断裂韧性并且研究它的其他性能。此外还利用SPS烧结技术制备、研究可加工ZrO2陶瓷材料。本论文重点研究了长石瓷晶相含量和晶粒度对断裂韧性的影响。晶相含量小于10vol%时,长石瓷随着晶相含量的增加KIC值呈现明显的上升趋势。但随着晶相含量的进一步增加,KIC值不再进一步提高而稳定在1.50-1.64MPa·m1/2。经XRD衍射分析,长石瓷烧结前后晶相都是微斜长石相。SPS制备长石瓷中的晶相是原粉料中晶体烧结后残留的。所以升温速度和烧结温度对长石烧结体的晶相含量和晶粒度起着非常重要的作用。对于粒度为2-9μm的长石瓷烧结温度大概在1100-1160℃之间。此外,最佳升温速度应控制在150-200℃/min。粉料粒度也是影响晶相的一个重要因素。随着粉料粒度的减小晶相含量和晶粒度都呈现变小的趋势。粉料粒度控制在2-7μm之间可获得晶粒度和晶相含量的最佳结合点。此时长石瓷的断裂韧性达到最高值（1.64MPa·m1/2）。HA加入到长石中可以解决长石在SPS中烧结容易变黑的问题。对烧结工艺没有影响。并且随HA含量的增加,样品的白度增加,透光率下降。当HA含量在5-10wt%时,长石瓷具有接近牙齿的色泽和半透明性。KIC值也能达到1.49MPa·m1/2,基本没有削弱纯长石瓷的断裂韧性。着色剂CeO₂和V₂O₅共同加入到长石中,可以得到接近人体牙齿颜色的黄红色陶瓷材料。其KIC值也能达到1.40MPa·m1/2,能够满足临床应用的要求。CAD/CAM加工实验结果表明,自制长石瓷具有良好的可加工性,与牙体的咬合效果良好。采用急性溶血实验和细胞毒性实验进行生物相容性初筛实验的结果表明,采用SPS制备的长石瓷材料生物相容性良好,均能够满足临床应用的初步要求。SPS烧结制备了可加工ZrO2-氟金云母复合材料,研究表明烧结体中ZrO₂更多还原

【Abstract】 Following the advancement of CAD/CAM (computer aided design/computer aided manufacturing) technic and pursuing for esthetics to many people, the machinable dental ceramic is more and more popular in the dental sufferers. At present, The color of machinable feldspathetic porcelain that has been applying to clinic is the most similar to nature teeth. It can show the vitality of nature teeth. But feldspathetic porcelain is too brittle and fracture toughness is very low. So it fails in clinic for often. The aim of the paper is to improve fracture toughness value of feldspathic porcelain by making use of the special sintering mechanism of spark plasma sintering (SPS) and to study other performances of feldspathic porcelain. Besides, machinable ZrO2 material is also researched prepared by SPS technique.The effect of crystal content and grain size of feldspathic porcelain on fracture toughness was discussed in the paper. When crystal content is under of 10wt%, The KIC value of feldspathic porcelain is ascending obviously with the increase of crystal content. But the KIC value does not improve any more and keeping the value of 1.50-1.64 MPa·m1/2, although the crystal content maintains increasing. According to the analytic result of X-Ray Diffraction, The crystal is microcline (KAlSi3O8). The crystal in feldspathic porcelain prepared by SPS is left from the crystal of power after sintering. As a result, the heating rate and sintering temperature play an important part in the crystal content and grain size. The sintering temperature of feldspathic porcelain is between 1100℃and 1160℃when the particle size is between 2μm and 9μm. Besides, the proper heating rate should be controlled between 150℃/min and 200℃/min. Otherwise, particle size is another important factor which influences crystal. Both The crystal content and grain size tend to lessen with the minishing of particle size. It can gain the best combining point when the particle size is controlled between 2μm and 7μm and the fracture toughness value can reach maximum value(1.64 MPa·m1/2).The problem that feldspathic porcelain samples are apt to darken after sintering in SPS can be solved effectively by adding HA to feldspathic porcelain, which can not更多还原