ZrO₂ Toughened Al₂0₃-La₂0₃/Y₂0₃ Mechanical Properties And Wear Resistance Of Ceramic Materials Research

Zirconia toughened alumina ceramic(ZTA) due to its high strength, high hardness, corrosion resistance, low cost, etc., at high temperatures, mechanical,electronic fields has been widely used. With the further development of research and application, the single-phase enhancement, overall performance toughened alumina ceramics or can not meet the needs of the aerospace, transportation and other fields.Synergy reinforced by multiple ZTA ceramic composite ceramics become enhance fracture toughness and wear resistance of important research and development.In this paper, the structure of the ceramic ZTA high wear resistance, high strength characteristics, combined with the rare earth oxide can promote technological features hot sintered composite ceramic material, in the material composition and the sintering process parameter optimization based on the ZTA-based composite prepared La2O3/Y2O3 ceramic material; measuring the mechanical properties of the material parameters; the influence of La2O3/Y2O3 content on the ZTA ceramic friction properties and wear resistance. The main contents are as follows:1. The uniform mixing, refining and other means to prepare different types,different contents of rare-earth doped ZTA composite powders. We developed a powder preparation process, using XRD, SEM and other testing methods for composite powders phase composition, microstructure and other analysis.2. Vacuum hot pressing process, combined ZrO2 composite phase transformation toughening and adding rare earth oxides promote sintering characteristics and material properties to Al2O3 as matrix, ZrO2 as toughening phase,La2O3/Y2O3 as sintering aids, a series ZTA ceramic materials; by the mechanical properties of the sintered samples to detect and compare and get the best recipe than sintering and sintering process parameters. Tests showed that: the best recipe for component content ZrO220wt%, La2O3/Y2O34wt%; the optimum parameters for the sintering process: sintering temperature 1550℃, sintering pressure 30 Mpa, holding time 40Min; testing the samples to get the best mechanics performance parameters:the relative density of 98.2%, a Vickers hardness 17.3 GPa, bending strength 445 MPa,fracture toughness of 7.6 MPa?m1/2.3. Using XRD diffraction analyzes the influence of rare earth oxide La2O3/Y2O3 phase component of the ZTA material is formed. The results showed that: ZTAcomposite La2O3/Y2O3 ceramic material during sintering chemical compatibility, no chemical reaction; La2O3/Y2O3 can hinder the formation of unstable phase m-ZrO2,and promote the formation of stable phase t-ZrO2, which in turn promote the ZTA sintering, effectively improve the mechanical properties of ZTA ceramic materials.4. ZTA ceramic samples with different La2O3/Y2O3 content of the wear test,analysis and research of La2O3/Y2O3 content on the ZTA ceramic material wear rate,the average coefficient of friction, such as the formation of microstructures. Studies have shown that: La2O3/Y2O3 content 4wt% of ZTA ceramic sample average wear rate and low coefficient of friction, more uniform particle microstructure formation,wear little crack morphology, low porosity, high density, good wear resistance.