表面处理对激光选区熔化成型纯钛钛瓷结合强度的影响

Effect of surface treatment on the three-point bend bonding strength between pure titanium fabricated by selective laser melting and porcelain

目的:探讨表面处理对激光选区熔化(selective laser melting,SLM)成型纯钛钛瓷结合强度的影响。方法:采用SLM技术制作纯钛条64个,钴铬合金条16个(25.0 mm×3.0 mm×0.5 mm)。根据喷砂压力及中间层将纯钛试件分为4组,TB1组为0.25 MPa喷砂的粘接瓷组,TG1组为0.25 MPa喷砂的金涂层,TB2组为0.45 MPa喷砂的粘接瓷,TG2组为0.45 MPa喷砂的金涂层,各组一半烤瓷试件进行10 000次冷热循环实验(n=8)。以0.25 MPa及0.45 MPa压力喷砂的钴铬合金金瓷结合强度作为对照,记为C1、C2组(n=8)。利用经典三点弯曲实验测试烤瓷试件的金瓷粘接强度,使用激光扫描共聚焦显微镜测量纯钛表面粗糙度,使用场发射扫描电镜观察钛瓷结合界面形貌,使用体视显微镜观察瓷剥脱后钛表面形貌并分析断裂模式,采用Graphpad Prism 8.0软件包对数据进行统计学分析。结果:钛瓷结合强度TG2组(40.16±3.97) MPa显著高于TB2组(36.32±1.44) MPa,TG1组(37.38±2.39) MPa显著高于TB1组(33.75±2.31) MPa(P<0.05),TB2组显著高于TB1组(P<0.05)。冷热循环后钛瓷结合强度未见明显下降。喷砂压力从0.25 MPa增加至0.45 MPa时,钛表面粗糙度随之显著增加(P<0.05)。纯钛组断裂模式均为混合断裂。结论:本实验条件下,与粘接瓷相比,金涂层可显著提高Ti22瓷粉与SLM纯钛的结合强度,增加喷砂压力可进一步改善钛瓷结合。冷热循环10 000次后,钛瓷结合强度未见显著降低。

PURPOSE:To evaluate the effect of surface treatment on bonding strength between pure titanium formed by selective laser melting and porcelain.METHODS:Pure titanium strips(64)and cobalt-chromium alloy strips(16)were laser machined to meet ISO 9693 standards.The pure titanium specimens were divided into 4 groups according to the sandblasting pressure and interlayer material.The sandblasting pressure of 0.25 MPa of bonder porcelain group was TB1,the sandblasting pressure of 0.25 MPa of gold coating group was TG1,the sandblasting pressure of 0.45 MPa of bonder porcelain group was TB2,and the sandblasting pressure of 0.45 MPa of the gold coating group was TG2(n=16).After porcelain fusing,half of the specimens in each group were tested for three-point bend bonding strength,and the other half were tested after 10000 cycles of thermal cycling(n=8).The bonding strength of cobalt-chromium alloy after sandblasting at 0.25 MPa and 0.45 MPa was taken as the control group and recorded as group C1,C2(n=8).The bonding strength was tested using classical three-point bending experiment.The surface roughness of pure titanium was measured by laser scanning confocal microscope(LSCM).Field emission scanning electron microscopy(FE-SEM)was used to observe the interface morphology of titanium-ceramic.The surface morphology of titanium after porcelain stripping was observed with stereomicroscope and fracture modes were analyzed by it.Graphpad Prism 8.0 software package was used for statistical analysis of the data.RESULTS:The bonding strength of group TG2 was(40.16±3.97)MPa and(37.38±2.39)MPa of group TG1,which were significantly higher than that of group TB2(36.32±1.44)MPa and group TB1(33.75±2.31)MPa(P<0.05).The bonding strength of group TB2 with 0.45 MPa sandblasting was significantly higher than that of group TB1 with 0.25 MPa sandblasting(P<0.05).There was no significant decrease in titanium-ceramic bonding strength before and after thermal cycling.When the sandblasting pressure increased from 0.25 MPa to 0.45 MPa,the roughness increased significantly(P<0.05).The fracture modes were mixed.CONCLUSIONS:Under the conditions of this study,gold coating can significantly improve the bonding strength of Ti22 porcelain and SLM pure titanium than bonder porcelain,and increase of sandblasting pressure can further improve the bonding strength of titanium-porcelain.After 10000 cycles of thermal cycling,the titanium-porcelain bonding strength did not decrease significantly.