Preparation And Properties Of Aesthetic Zirconia Ceramics

Zirconia ceramics have both excellent mechanical properties and aesthetic color,and are very popular in the field of personal consumer electronic devices such as mobile phone shells.At present,the color of zirconia mobile phone shells is relatively simple and cannot meet the needs of personalized colors.In this paper,the solid-phase mixing method and the liquid-phase infiltration method were used to prepare aesthetic zirconia,and the effect of the preparation process on the mechanical properties and color of the aesthetic zirconia ceramics was studied.Using Ni O and Al₂O₃ as raw materials at a temperature of 1000°C?1550°C,a sky-blue pigment was synthesized by solid-phase mixing method,and the calcination temperature and ratio of the pigment were optimized.Studies showed that when the calcination temperature is higher than 1350°C,the synthetic pigment changes from green to sky-blue.XRD results showed that Al₂O₃ and Ni O are in solution to form Ni Al₂O₄spinel;XPS results showed that Ni Al₂O₄ lattice distortion is caused by solid solution,which shifts the Ni binding energy and eventually leads to color change.The CIE L*a*b*system chromaticity was tested on the synthetic pigment,and the optimal conditions for the synthetic sky-blue pigment were obtained:the initial raw material molar ratio Al/Ni=3:1,and the sintering temperature was 1450°C.At this time,the sky-blue pigment chromaticity value L*=74.6;a*=-23.4;b*=-26.3.The solid-phase mixing method was used to prepare sky-blue zirconia ceramics,and the effects of the amount of pigment added,sintering temperature,etc.On the density,bending strength,and chromaticity of the final colored zirconia were studied.Studies showed that with the addition of pigment increased,the density and bending strength of the final colored zirconia decrease.When the sintering temperature is 1450°C and the amount of pigment added is 2.5 wt.%,the comprehensive performance of the synthesized colored zirconia is optimal.At this time,the sample color L*=64.7,a*=-22.2,b*=-24.5,density?=5.99 g/cm³,and bending strength is 1060±40 MPa.The sky-blue zirconia ceramics were prepared by liquid-phase infiltration,and the effect of the concentration of colored ions on the color,density and bending strength of the synthesized sky-blue zirconia was studied.Analysis of the test results showed that the optimal ion concentration is:c(Al³⁺)=0.50 mol/L,c(Ni²⁺)=0.25 mol/L.By XRD and SEM characterization,no Ni Al₂O₄ pigment particles were detected.The density and bending strength of colored zirconia synthesized by liquid-phase infiltration method are superior to those of solid-phase method,and the experimental operation is faster and more efficient,so as to facilitate the exploration of the preparation of aesthetic zirconia of different colors.According to the principle of the three primary colors,green zirconia ceramics were prepared by using the liquid-phase infiltration method using the sky-blue pigment ions Ni²⁺,Al³⁺and yellow pigment VO₃^-.The effects of color ion concentration and immersion time on the color of green zirconia ceramics were also studied.The results showed that the pigment ion concentration is c(Al³⁺)=0.50 mol/L,c(Ni²⁺)=0.25 mol/L,c?VO₃^-?=0.005mol/L,the immersion time is 2 min,and the chromaticity of green zirconia is the best.Using this as a guide,green zirconia was prepared by the solid-phase method.