Microstructure and Properties of Zirconia Toughened Alumina Fabricated by Powder Injection Moulding

Abstract:

Zirconia toughened alumina (ZTA) ceramic has been fabricated by the powder injection moulding process. The ZTA ceramic, composed of 80 wt% alumina and 20 wt% zirconia, was mixed with a water-soluble, multi-component binder system. The binder ingredients were polyethylene glycol (PEG), polyvinyl butyral (PVB) and stearic acid (SA). Powder injection moulding was performed with powder loadings in the range of 48-52 vol%, using a laboratory-scale injection moulding machine. Water leaching was used for partial binder removal prior to thermal debinding and then sintering at 1650 °C for 2 hours. Microstructural examination of the ZTA ceramic revealed that zirconia inhibited alumina grain growth and, therefore, improved the mechanical and physical properties of the specimens. It was found that powder loading had an influence on density, hardness and strength of the specimens. A flexural strength of 334 MPa and hardness value of 2093 kg/mm² was obtained from specimens injection moulded with 52 vol% powder loading feedstock. The highest sintered density achieved was 97% of the theoretical value.

• Periodical: Key Engineering Materials (Volume 659)
• Pages: 116-120
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.659.116
• Online since: August 2015
• Authors: Nutthita Chuankrerkkul*, Rattanaporn Charoenkijmongkol, Punnapa Somboonthanasarn, Chiraporn Auechalitanukul, Ryan C. McCuiston
• Keywords: Ceramic Injection Moulding, Water Soluble Binder, ZTA Ceramic

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