Y－TZP纳米陶瓷的制备

On Preparing Dense Crystalline 3Y-TZP Ceramics 120nm in Grain Diameter

用化学共沉淀凝胶法制备了晶粒度为７．６ｎｍ的３ｍｏｌ％Ｙ２Ｏ３－ＺｒＯ２纳米粉末，所得粉末不仅尺寸小、分布均匀，且分散性好。对该粉末制成的素坯，通过烧结过程中晶粒生长的控制，在１２５０℃／２ｈ常压烧结条件下获得了晶粒尺寸约为１２０ｎｍ的致密陶瓷体。

To the best of our knowledge, the smallest grains of crystalline 3Y-TZP ceramics arethose of about 120nm obtained by Qiu et al in a Chinese national laboratory in Shanghai [3].But Qiu et al used fast sintering process. In this paper, we present our Tesearch findingsabout how to get such grains 120nm in diameter under pressureless sintering conditions.3Y-TZP ceramics should be not only small in grain size but also dense. This is ratherdifficult to achieve. We adopt two technical methods for achieving it:(1) Use of NH4Cl as dispersion agent, we find that thougth NH4Cl in small amountcauses unwelcome agglomeration, but when in sufficient amount, it serves as effective dispersion agent.(2) Suitable control of grain growth in pressureless sintering process. Thus ultra-fine 3mol%Y2O3-ZrO2 powder with all particles quite near 7. 6nm in diameter (Fig. 2) is prepared with our chemical co-precipitation gel method. Grains of onlyabout 120nm (Fig. 5 is an SEM photo) of dense 3Y-TZP ceramics are obtained.