YAG-Al2O3纳米复合材料的制备和力学性能

摘要

25vol%YAG-Al2 O3 nanocomposite powders were prepared by the co-precipitaion method from ytrium nitrate and aluminium nitrate as starting materials. The XRD pattern for the prepared powder calcined at 1300 ℃ for 1h shows well-defined peaks whose positions are almost identical to those of stoichometic YAG and α-Al2 O3. The powder compacts by hot-press sintering for 0.5 h at 1400 ℃ and 300MPa reached a density close to the thoretical, while the normally reported hot-press sintering temperature for YAG-Al2 O3 composites is 1600 ℃. The bending strength and fracture toughness of prepared 25vol%YAG-Al2 O3 nanocomposite were 612 MPa and 4.54 MPa.m-1/2, respectively, which are much higher than those of monolithic A l2 O3 and monolithic YAG, as well as higher than those reported in other studies for YAG-A l2 O3 composites.Microstructure studies found that the nano-YAG particles were mainly located within the Al2 O3grains.%本文介绍用化学共沉淀和在适当温度下煅烧以直接制备YAG-Al2 O3纳米复合粉体的新方法．XRD结果表明，所得粉体具纯的YAG和α-Al2 O3相，因此其化学组成符合配料的组分设计．用本方法制备的25vol％YAG-Al2 O3复合粉体经热压烧结，所得的致密体材料为晶内型纳米复合材料，其抗弯强度达612MPa，断裂韧性为4．54MPa．m-1/2，都比单相Al2 O 3陶瓷有大幅度提高．