Densification and Phase Transformation During Pressureless Sintering of Nanocrystalline ZrO ₂ –Y ₂ O ₃ –CuO Ternary System

ZrO 2 –Y 2 O 3 –CuO nanocrystalline powders have been synthesized using a chemical coprecipitation method. Nano‐powders were compacted uniaxially and densified in a muffle furnace. Densification studies show that the presence of CuO accelerates the densification process of ZrO 2 (3Y). A fully dense (>96%) pellet of ZrO 2 (3Y)/5 mol% CuO was obtained after sintering at 900°C, with a very small grain size of 44 nm calculated by X‐ray line broadening.