超韧牙科氟金云母玻璃陶瓷的可加工性能初探

Machinable property of a novel dental mica glass-ceramic

目的分析不同品化温度和晶化时间对一种氟金云母玻璃陶瓷加工性能的影响,探讨其延性切削行为的机制。方法使用 SiO_2-B_2O_3-R_2O-Al_2O_3-ZnO-MgO-F(R 为碱金属)玻璃陶瓷粉制备晶化温度和晶化时间分别为650℃(60 min)、680℃(60 min)、710℃(60 min)、740℃(60 min)、680℃(30 min)、680℃(120 min)、680℃(240 min)的试件,分为 A、B、C、D、E、F、G 组,每组6个;长石质可切削陶瓷试件作为对照组。测定8组试件钻孔30 s 后的钻孔深度,并进行车床切削实验定性分析。扫描电镜和 X 射线衍射分析观察试件的微观结构。结果 A 组钻孔深度最大,为(7.1±0.8)mm;D 组最小,为(0.5±0.1)mm。除 D 组外,其余组钻孔深度均大于对照组[(0.8±0.1)mm],差异均有统计学意义(P<0.05)。A 组试件可在普通车床高速车削条件下形成连续带状切屑,其晶体相含量约为40%。结论这种云母玻璃陶瓷具有良好的可加工性,其机制可能与云母晶体的互锁结构和玻璃相黏滞流动作用相关。

Objective To investigate the machinability of a novel dental mica glass-ceramic and analyze the effect of heat-treatment on its ductile machinable behavior. Methods The drilling and turning experiment were used to measure the machinabilities of the control group （feldspar ceramic： Vita Mark 11 ） and 7 experiment groups treated with different crystallization techniques. The microstructures were analyzed using scanning electron microscopy （ SEM ） and X-ray diffraction （ XRD ）. Results The average drilling depths in 30 s of the experimental groups ranged from （ 0. 5 ±0. 1 ） mm to （ 7. 1 ± 0. 8 ） mm. There were significant differences between the control [ （ 0. 8 ±0. 1 ） mm ] and the experimental groups （ P 〈 0. 05 ） except the group crystallized at 740 ℃ for 60 min. When crystallized at 650 ℃（60 min） ,continuous band chips could formed in machining at a high velocity and cut depth. The crystal portion of this group is only about 40%. Conclusions This material has a satisfactory machinability. The mechanism could be attributed to a combination of the interlocked structure of mica crystals and the low viscosity of glassy phase.