纯钛表面电火花沉积中间层对钛瓷结合强度的影响

目的：探讨在铸造纯钛表面电火花沉积技术制备中间层对钛瓷结合强度的影响。方法：将40个纯钛试件平均分为4组,分别用硅、锆及钴铬合金电极通过电火花沉积技术在其表面制备中间层,对照组不作沉积处理,喷砂后测各组试件的表面粗糙度。参照IS0 9693（1999）Amd.1 2005（E）标准在试件中份烧结Ti-22瓷粉,测钛瓷间的三点弯曲结合强度。对钛瓷结合界面进行扫描电镜观察及X射线能谱分析。用X射线衍射分析仪分析硅电极组中间层的结构。结果：喷砂后各组试件表面粗糙度差异无显著性,硅电极组钛瓷间的三点弯曲结合强度最高,为（33.38±3.67）MPa,较其他3组结合强度差异有显著性（P〈0.05）,其他3组间钛瓷结合强度差异无显著性。扫描电镜观察显示各组试件钛瓷结合界面均未见明显氧化层,硅电极组可见中间层与钛基材间有约15～20μm的过渡层。X射线衍射分析结果提示硅电极组中间层中有TiN、Ti5Si3及TiSi2生成。结论：通过电火花沉积技术用硅电极在铸造纯钛表面制备中间层可提高其钛瓷结合强度。

Effect of Middle Layer by Electro-spark Deposition Technology on Bonding Strength of Porcelain and Cast Pure Titanium

Objective：To investigate the effect of middle layer by electro-spark deposition（ESD） technology on bonding strength of titanium and porcelain.Methods：Forty pure titanium specimens with the size of 25mm×3mm×0.5mm were randomly divided into four groups（n=10） according to four different surface treatments：untreated control,Si electrode group,Zr electrode group and CoCr electrode group.We sandblasted four groups and measured the roughness.After the middle area of the samples were veneered with Ti-22 system,a three-point-flexure-test was used to evaluate the bonding strength of titanium to porcelain.The interface of titanium and porcelain was investigated by scanning electron microscope（SEM） with energy disperse spectroscopy（EDS）.The phase composition of Si electrode group specimens was characterized by X-ray diffraction（XRD）.Results：There were no significant difference in the roughness among four groups after sandblasting.The mean bonding strength of Si electrode group was the highest（33.38±3.67MPa）,it was significantly higher than those of other three groups（P〈0.05）,and there were no significant difference in the bonding strength among those of other three groups.No definite oxide layer was observed at the interfaces in four groups.A 15-20μm thick transition layer was observed between middle layer and titanium in Si electrode group.TiN,Ti5Si3 and TiSi2 were characterized by X-ray diffraction in Si electrode group specimens.Conclusion：Middle layer prepared by ESD technology using Si electrode significantly improves bonding strength of porcelain and cast pure titanium.