氧化锆增韧氧化铝复合陶瓷制备及性能研究

Preparation and Properties of Zirconia Toughened Alumina Composite

本实验以纳米3Y-TZP和微米Al2O3为主要原料,采用常压烧结法制备致密的纳米ZTA复相陶瓷材料。当3Y-TZP含量为30wt%时,其相对密度达到最高,如烧结温度为1 400℃,试样的相对密度高达96.35%。在烧结温度范围内,试样中的颗粒会随着烧结温度的升高而增大,Al2O3颗粒随着3Y-TZP含量的增加而变小。纳米级的3Y-TZP颗粒会形成"內晶型"结构。在烧结温度为1 450℃时,含30wt%3Y-TZP的试样抗弯强度高达441.22MPa。

ZTA composite ceramics have been widely used in many areas with the good performance. In the experiment, 3Y TZP and A120 as raw materials, the dense nano ZTA composite ceramics were prepared by pressureless sintering. Effects of different zirconia content on the densification, microstructure, phase composition and mechanical properties of 3Y TZP/A12O3 composite ceramics were investigated. The results show that density of ZTA composite ceramics will first increase and then decrease when the 3Y -TZP content increase. 3Y -TZP nano particles can be distributed over particles in the matrix grain boundaries, so that the sample density increased. When the 3Y TZP content was 30wt% , its highest density, such as sintering temperature is 1100 ℃, the density as high as 96.35%. If you continue to improve the content of 3Y-TZP, the density will decline due to the excessive nano particle agglomeration. And in a range of Sintering tempera ture, ceramic density will increase with the increase of sintering temperature. The phase of powder with mechanical mixture mainly composed of α-A1203 and t-ZrO2. With high temperature sintering, the phase in specimen is α-A120 , t-ZrO2 and m-ZrO2. In the sinteringtemperature range, particles will become lager with sintering temperature increasing, and be smaller with content of 3Y-TZP increasing. The nano particles of 3Y-TZP will be to form the crystal structure. When the sintering temperature being 1450 ℃ , bending strength of the specimen containing 30wt% 3Y-TZP up to 44 1.22 MPa. Nano particles can inhibit the grain growth, grain can hinder crack extension, and improve the mechanical properties.