掺镁氧化铝复相绝缘陶瓷的制备及性能研究OA

Alumina ceramics are widely used in mechanical,electronic,and aerospace fields due to their excellent mechanical properties and high-temperature resistance.However,pure Al2O3 ceramics are prone to abnormal grain growth and residual porosity during sintering,limiting further performance en-hancement.The study employed MgO as a structural stabilizer and utilized an L9(34)orthogonal experi-mental design to systematically investigate the effects of MgO doping concentration,holding temperature,holding time,and cooling rate on the microstructure,mechanical properties,and dielectric properties of MgO-doped alumina composite ceramics.Phase composition and fracture morphology were characterized via XRD and SEM,while three-point bending strength,Vickers hardness,and dielectric breakdown strength were measured.Results indicate that the three-point bending strength of MgO-doped speci-mens increased by up to 105.66 MPa,with Vickers hardness reaching 15.83 GPa.Range analysis re-vealed the primary factors affecting strength were cooling rate＞holding temperature＞MgO doping a-mount＞holding time;while the primary factors affecting hardness were holding temperature＞MgO do-ping amount＞holding time＞cooling rate.Dielectric testing revealed that magnesium-doped samples exhibited significantly enhanced breakdown field strength and Weibull modulus due to increased grain boundaries and optimized pore distribution,thereby improving insulation reliability.The author aims to explore the feasibility of preparing Al2O3-MgAl2O4 multiphase ceramics using Al(OH)3 as the alumi-num source and with a relatively high MgO doping level,and to systematically optimize the process pa-rameters.The result provides a theoretical basis for the process optimization and industrial application of high-performance alumina ceramics.