三种稀土氧化物着色剂对氧化钇稳定的四方多晶氧化锆陶瓷性能的影响

目的采用3种稀土氧化物对纳米3mol%氧化钇稳定的四方多晶氧化锆(3Y TZP)粉体进行着色,实验分析着色剂对烧结体色度和性能的影响。方法在3Y TZP粉体中分别掺入不同质量分数的Pr6O11、Er2O3和CeO2,200MPa冷等静压成型,常压烧结,升温速率150℃/h,保温2h。测量烧结体的色度值、三点挠曲强度、维氏硬度和断裂韧性。用Archimedes法测试烧结体密度。通过扫描电镜和X线衍射比较稀土氧化物对3Y TZP陶瓷显微结构和晶相的影响。结果CeO2和Pr6O11使3Y TZP陶瓷呈黄色,Er2O3使3Y TZP陶瓷呈红色,但3种稀土氧化物对3Y TZP陶瓷明度的影响均不大。3种稀土氧化物主要降低3Y TZP陶瓷的三点挠曲强度,从纯3Y TZP试件的(1536.37±85.49)MPa,下降到1%Er2O3添加时的(534.11±57.06)MPa。对维氏硬度和断裂韧性的影响较小。微量着色剂对3Y TZP烧结体的晶相无明显影响,但可使其孔隙增多且与剂量有关。结论稀土氧化物能够赋予3Y TZP陶瓷所需的色度值,其对3Y TZP性能的影响尚待进一步研究。

Effect of three kinds of rare earth oxides on chromaticity and mechanical properties of zirconia ceramic

OBJECTIVE: To evaluate the colouration of zirconia ceramic by adding three kinds of rare earth oxides. The influence of the pigments concentration on the mechanical properties and the microstructure was also analyzed. METHODS: Added different concentrations of CeO(2), Er(2)O(3) and Pr(6)O(11) in tetragonal zirconia poly crystals stabilized with 3 mol% yttria (3Y-T2P) powder, compacted at 200 MPa using cold isostatic pressure, and sintered to 1 400 degrees C. The heating rate was 150 degrees C/h and the dwelling time was 2 hours. The chromaticity of sintered bodies was measured with chroma meter. The relative density, hardness, flexure strength and fracture toughness were investigated as well. The phase stability of the colorized and pure zirconia was evaluated by X-ray diffraction (XRD) using an automated diffractometer. The microstructures of the specimens were evaluated by scanning electron microscope (SEM). RESULTS: Several kinds of color achieved by the different pigments praseodym oxide, cerium oxide and erbium oxide were presented in the CIELab system. The a* value increased with the added amount of Er(2)O(3), while b* value rose with the increasing amount of CeO(2) and Pr(6)O(11). However, three pigments failed to decrease L* value and the sintered body appeared too bright. Adding three pigments influenced flexure strength of zirconia ceramic significantly, but had little influence on the hardness and fracture toughness. Microscopy revealed the relationship between the porosity and shapes of grains was correlated to strength of the diphase ceramics. No additional phase could be detected by XRD, except t-ZrO(2) in all colorized samples after sintering at 1 400 degrees C for 120 min. CONCLUSIONS: Zirconia ceramic can be colorized by CeO(2), Er(2)O(3), and Pr(6)O(11). Pigments even in a small amount influence the mechanical properties of the colorized zirconia material, which necessitates further investigation.