Effects of γ-Al_2O_3 on the Forming Ability of CeO_2-ZrO_2 Solid Solution and their Stability

The phase transformation and thermal stability of γ-Al_2O_3 with CeO_2 and ZrO_2 during high-energy ball milling and annealing were investigated by means of X-ray diffractometry(XRD).The effects of γ-Al_2O_3 on the forming ability of CeO_2-ZrO_2 solid solution and their stability were studied.The results show that it is easy for CeO_2 and ZrO_2 to form solid solution during milling.However,it becomes difficult for CeO_2 and ZrO_2 to form solid solution when γ-Al_2O_3 is added since γ-Al_2O_3 restrains the diffusion between CeO_2 and ZrO_2.Meanwhile,γ-Al_2O_3 doesn't dissolve into CeO_2 or ZrO_2 during milling.Moreover,a good way to prepare milled powders is that CeO_2 and ZrO_2 are firstly milled for 30h and then γ-Al_2O_3 is added and milled for another 30h.In this way,the composite of γ-Al_2O_3 and CeO_2-ZrO_2 solid solution with higher structural stability is produced.The thermal stability of CeO_2-ZrO_2 solid solution is improved by γAl_2O_3.And the structure of γ-Al_2O_3 is stabilized by CeO_2-ZrO_2 solid solution in return.The transformation of γ-Al_2O_3 to α-Al_2O_3 during milling is effectively restrained and the phase transformation temperature during heating increases.The thermal stability of γ-Al_2O_3 powder is improved by CeO_2-ZrO_2 solid solution.