Processing and characterisation of new nanocrystalline Al2O3?fly ash composites. (21st January 2009)

• Record Type: Journal Article
• Authors: Saheb, N.; Yoong, T.C.
• Is Part Of: International journal of microstructure and materials properties. Volume 3:Number 6(2008)
• Page Start: 801
• Page End: 809
• Publication Date: 2009-01-21
• Subjects: nanocrystalline aluminium oxide -- fly ash -- compaction -- sintering -- ceramic matrix composites -- CMCs -- powder metallurgy -- structural materials -- micohardness; Microstructure -- Periodicals; Materials -- Properties -- Periodicals; 620.11299
• Languages: English
• ISSNs: 1741-8410

Abstract

In this study, new nanocrystalline Al2O3?fly ash Ceramic Matrix Composites (CMCs) were developed through the powder metallurgy route. It was found that wet milling of the mixture for 18 h improved mixing, decreased the Al2O3 crystallite size to around 10 nm, and reduced the fly ash particle size. For samples sintered at 1350°C for 16 h, the addition of 5 wt% fly ash to alumina increased the micohardness from 525 to 1325 HV while the addition of 10 and 20 wt% decreased it to 508 and 444 HV respectively. Composites containing 5 and 10 wt% fly ash had higher density than Al2O3, while samples containing 20 wt% fly ash had lower density. Increasing the sintering time led to the increase in the density of all the samples sintered at 1350°C.