Fabrication of Nd:YAG transparent ceramics from co-precipitated powders by vacuum pre-sintering and HIP post-treatment

Using the nanopowders made by a reverse co-precipitation as raw materials, neodymium doped yttrium aluminum garnet (Nd:YAG) transparent ceramics were fabricated by vacuum pre-sintering with subsequent hot isostatic pressing (HIP) post-treatment. The green bodies were pre-sintered in vacuum at 1450 o C–1800 °C for 2 h and then HIPed at 1750 °C for 3 h under 200 MPa Ar atmosphere. Densification behavior and microstructure of the Nd:YAG ceramics before and after the HIP-treatment were investigated. Influences of the annealing temperature on transmittance and microstructure of the Nd:YAG ceramics were also studied. The ceramics pre-sintered at 1750 °C for 2 h and post-HIPed at 1750 °C for 3 h without any additional annealing in air were shown to have the best in-line transmittance of 79.1% at 1064 nm.