氧化锆增韧纳米复合陶瓷粉体粒度与基体强度的关系

Study of relationship between powder-size gradation and mechanical properties of Zirconia toughened glass infiltrated nanometer-ceramic composite powder

目的 探讨氧化锆 (ZrO2 )粉体微观粒度、级配与材料增韧补强效果之间的关系。方法以采用包裹共沉淀法与湿法球磨方法合成的Al2 O3 nZrO2 纳米复合陶瓷粉体为研究对象 ,改变所添加ZrO2 粉体的粒度 ,对粉体形貌进行扫描电镜观察与粉体粒径的测定分析 ;以注浆法将粉体制成样本生坯 ,经 1 4 50℃烧结后 ,测定样本的抗弯强度与断裂韧性。结果 ①添加等量、不同粒度ZrO2 的Al2 O3 nZrO2 纳米复合渗透陶瓷材料 ,其基体抗弯强度与断裂韧性差异有显著性 (P <0 0 5) ;②添加粒度分布范围在 0 0 2～ 3 5μm ,包含粒径小于 0 5μm超细颗粒的ZrO2 组 ,增韧增强效果最显著 ,抗弯强度与断裂韧性分别达 (1 1 5 434± 5 31 9)MPa和 (2 0 4± 0 1 0 )MPam1 /2 。结论 添加ZrO2 的粉体粒度与级配是影响Al2 O3 nZrO2

Objective The fabrication of all ceramic dental restorations is challenged by ceramics′ relatively low flexural strength and intrinsic poor resistance to fracture This paper aimed at investigating the relationships between powder size gradation and mechanical properties of Zirconia toughened glass infiltrated nanometer ceramic composite (Al 2O 3 nZrO 2) Methods Al 2O 3 nZrO 2 ceramics powder (W) was processed by combination methods of chemical co precipitation and ball milling with addition of different powder sized ZrO 2 Field emission scanning electron microscopy was used to determine the particle size distribution and characterize the particle morphology of powders The matrix compacts were made by slip casting technique and sintered to 1 450℃ and flexural strength and the fracture toughness of them were measured Results 1 The particle distribution of Al 2O 3 nZrO 2 ceramics powder ranges from 0 02～3 5μm and among them the superfine particles almost accounted for 20% 2 The ceramic matrix samples with addition of nZrO 2 (W) showed much higher flexural strength (115 434±5 319)MPa and fracture toughness (2 04±0 10)MPa m 1/2 than those of pure Al 2O 3 ceramics (62 763±7 220 MPa ;1 16±0 02 MPa m 1/2 ) Conclusions The particle size of additive ZrO 2 may impose influences on mechanical properties of Al 2O 3 nZrO 2 ceramics matrix Good homogeneity and reasonable powder size gradation of ceramic powder can improve the mechanical properties of material