Study On Coloring And Mechanical Properties Of Zirconia Ceramics

Zirconia ceramic is a new type of ceramic material with excellent mechanical properties,electrical conductivity,chemical stability and biocompatibility.It has been successfully applied in the field of dental denture restoration and electronic decorative materials.However,with the advancement of the scientific and technological society and the advent of 5G communication technology,people have improved the aesthetic requirements of dental restorations and decorative materials.The zirconia base porcelain is white which is too single to satisfy its further use and promotion.Therefore,in this paper,nano-zirconia powders?3Y-TZP,3 mol%Yttria-stabilized tetragonal zirconia polycrystals?was used as raw materials to prepare colored zirconia ceramics by mechanical mixing and immersion coloring.And the Fe-Cr-Mn system of black pigment was synthesized to prepare black zirconia ceramics.The effects of metal oxide colorants and spinel black pigments on the microstructure,coloring properties and mechanical properties of colored zirconia ceramics were studied.The main research results were as follows:?1?The 3Y-TZP ceramics were pigmented with Fe₂O₃,Pr₆O₁₁,Er₂O₃,and CeO₂metal oxides.The sintered body showed different color changes,the surface color was uniform,and the color difference between the front and back was small,and the average grain size was 200⁵00 nm.The CeO₂ coloring has a great influence on the mechanical properties of 3Y-TZP ceramic sintered body.When the CeO₂ doped content was 2.00 wt%,the three-point bending resistance of the sintered body was decreased to 842±28.59 MPa.When Fe₂O₃?0.03⁰.05 wt%?and Er₂O₃?0.10⁰.40wt%?mixed colorant were used,the regions of zirconia ceramics chromaticity values a*and b*can be well matched with the Vita 3D region.?2?The 3Y-TZP ceramics were colored by the method of immersion of Fe³⁺ions and Er³⁺ions colorant solution.The surface of the ceramic sintered body has uniform pale yellow color,and the yellowish color was deepened with the immersion time.The Fe³⁺ions increase the a*and b*values of the sintered body.However,the Er³⁺ions increase the a*value of the sintered body and decrease the b*value.Metal ions immersion coloring can slightly reduce the mechanical properties of the 3Y-TZP ceramic sintered body.The three-point bending strength of the sintered body is at least1098.56±38.08 MPa,the vickers hardness is at least 12.47±0.41 GPa,and the fracture toughness is at least 5.18±0.56 MPa·m^1/2.?3?The Fe-Cr-Mn pigments were synthesized by chemical coprecipitation and its average grain size is about 152.9 nm after calcination at 1200?.The spectral reflectance of Fe-Cr-Mn pigments the lowest at this the calcination temperature.The absorption intensity of black the largest in the visible range,and the color has a good black coloration effect.?4?The black zirconia ceramics prepared by doping Fe-Cr-Mn black pigment has a uniform and blackish black color.The microscopic test results show that a small number of pores appear on the surface of the prepared black zirconia ceramics,and it increases with the doping amount.When the doping amount of Fe-Cr-Mn coloring material is 3.00 wt%,the black zirconia ceramic has good mechanical properties.And its three-point bending strength,vickers hardness and fracture toughness is624.39±31.36 MPa,10.60±0.19 GPa and 7.02±0.43 MPa·m^1/2,respectively.