Effect of Ammonium Polyacrylate and Pre-Oxidation on Rheological Properties of Si₃N₄ Slurries

Abstract:

The key for gel-casting is the preparation of ceramic aqueous slurries with excellent rheological properties. The effect of ammonium polyacrylate and pre-oxidation on rheological properties of Si₃N₄ slurries was investigated. The Si₃N₄ isoelectric point (IEP) is between 3 and 4 in premix solution and particle surface potential is maximum at pH between 9.5 and 10.5. PAA-NH₄ of dispersant can obviously decrease the viscosity of Si₃N₄ slurries, and the optimal dosage is about 1.6wt% of Si₃N₄ powders. Meanwhile, the Si₃N₄ slurries exhibit pseudoplastic fluid with the characteristic of shear-thinning behavior. Due to the improvement of powder surface characteristic, the pre-oxidation significantly improve the rheological properties of the Si₃N₄ slurries.

• Periodical: Materials Science Forum (Volume 816)
• Pages: 102-106
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.816.102
• Online since: April 2015
• Authors: Chuan Bing Cheng, Run Hua Fan*, Ke Lan Yan, Kai Sun, Qian Qian Li, Qing Hou, Gui Fang Liu, Pei Tao Xie
• Keywords: Si₃N₄, Ammonium Polyacrylate, Gelcasting, Rheological Properties

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