粉体提纯对硅藻土陶瓷材料性能的影响研究

Effects of purification of diatomite powder on properties of ceramic materials

目的探讨硅藻土粉体的提纯对陶瓷材料机械性能及颜色的影响。方法将干压成型的硅藻土基陶瓷坯体在不同温度下进行烧结,测试烧结后陶瓷的弯曲强度、维氏硬度及断裂韧性,SEM观察断面的显微结构,用ShadeEye NCC比色仪对陶瓷成品进行色度值测定。结果不同最高烧结温度对提纯后硅藻土陶瓷的力学性能具有明显的影响,1 100℃表现出较佳的烧结性能,弯曲强度为(160.316±15.341)MPa、维氏硬度为(4.351±0.433)GPa、断裂韧性为(2.676±0.148)MPa.m1/2,较未提纯硅藻土陶瓷显著增加(P<0.05);线收缩率较未提纯组减小,为(13.027±0.131)%(P<0.05)。提纯后的色度值为L*=+(88.09±0.62),a*=-(1.87±0.09),b*=+(5.60±0.41),与未提纯组的色差值△E*ab达到了12.40±0.82。结论对硅藻土粉体的提纯能够提高其力学性能,使其更接近正常牙齿颜色,但仍需进一步提高其各项性能以满足临床牙科陶瓷材料的要求。

Objective To investigate the effects of purification of diatomite powder on mechanical properties and colors of ceramic materials.Methods The ceramic bodies were prepared with dry pressing method,then sintered at different temperatures.Measure the linear shrinkage and test the bending strength,Vicker shardness and fracture toughness of sintered ceramics.Observe the themicrostructures of the cross-sections of sintered ceramics with SEM.Then the color values were analysed with dental chromameter ShadeEye NCC.Results Sintering temperature had significant effects on the mechanical properties of purified diatomite ceramic.The mechanical properties were much better when the intering temperature was 1 100 ℃,σ3P=（160.316±15.341） MPa,HV=（4.351±0.433） GPa,KIC=（2.676±0.148） MPa·m1/2,ε=（13.027±0.131） %,which were better than those of the non-purified diatomite ceramics.The following values were the color values of the purified ones：L＊=＋（88.09±0.62）,a＊=-（1.87±0.09）,b＊=＋（5.60±0.41）,and the △E＊ab between the purified diatomite ceramics and the non-purified ones was 12.40±0.82.Conclusions Purification of the diatomite powder can improve the mechanical properties of the ceramics,making their colors closer to the colors of normal teeth.But further research is still needed to improve their properties to meet the requirements of clinical application.