Study On Sintering Behavior And Mechanical Properties Of Zirconia Ceramics

The development of 5G communication technology has increased the demand for signal transmission,anti-drop and wear resistance of mobile phone backplanes.Zirconia ceramics have excellent physical and chemical properties:high strength,high hardness,wear resistance,no signal shielding,corrosion resistance,strong chemical stability,etc.,making it a promising mobile phone backplane material.However,at present,the production and preparation technology of zirconia ceramic materials in China is relatively backward,the product yield is low,and the actual strength is quite different from the theory.Therefore,the research on the preparation of high-strength and high-toughness zirconia materials is of great significance.The subject is aimed at the unique brittleness of ceramic materials and the volume change caused by the phase transformation of zirconia,which makes the sintering preparation of pure zirconia ceramic samples often cracked.Zirconium oxide is doped with different contents of yttrium oxide,so that Y3+and Zr4+undergo solid solution reaction or replacement reaction,increase oxygen vacancies,and effectively retain more tetragonal phase at room temperature to improve toughness.And by using pressureless sintering,hot pressing sintering and spark plasma sintering process,the influence of Y2O3 content and sintering process on the sintering behavior and mechanical properties of zirconia ceramics was studied to optimize the process to prepare high-density,high-strength,high-toughness ceramics.Zirconia ceramic material.The sintering results show that the required densification temperature of zirconia ceramics increases gradually with the decrease of the Y doping content,which can be attributed to the decrease of the oxygen vacancy concentration in the sintered body with the decrease of the Y doping content,and the sintering driving force of the system decreases.The mechanical properties results show that with the decrease of Y doping content,the flexural strength and fracture toughness of the final material both increase;it can be attributed to that the phase stability of tetragonal zirconia decreases with the decrease of Y doping content,which is more likely to induce"phase"."Toughening"dissipates impact energy.By comparing the effects of pressure-less sintering,hot-pressing sintering and spark plasma sintering on the mechanical properties of zirconia ceramics,it is determined that the hot-pressing sintering process is more conducive to improving the mechanical properties of Y-TZP ceramics.Based on the optimized hot pressing sintering process,Y-TZP ceramics with a bending strength greater than 1435 MPa and a fracture toughness of 11 MPa·m^1/2were prepared.