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Fabrication of Toughened Alumina Nanocomposites Using γ-Alumina Powder

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Abstract:

To improve fracture strength and fracture toughness in ceramic materials, we focused our attention on an intra-type structure of nanocomposites. We proposed new processing method for fabricating intra-type nanocomposites. In this work, Al2O3/Ni nanocomposites were fabricated using a soaking method and sintered by PECS(Pulse Electric Current Sintering) method. We also estimated seed effects on this system. Seeded nanocomposites showed high fracture strength and higher fracture toughness than non-seeded nanocomposites and monolithic alumina. The fracture strength of the seeded nanocomposites was more than 800MPa in all sintering temperature range. The maximum value of the fracture toughness was 5.5 MPa⋅m1/2 for the specimen sintered at 1350°C. The sintered specimens with high fracture strength and high fracture toughness were annealed from 800°C to 1000°C for 0 to 10 min. The specimen annealed at 800°C for 5 min showed the highest fracture toughness of 7.6 MPa⋅m1/2. This value is two times higher than that of the monolithic alumina.

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AICAM 2005 View Preview

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Periodical:

Advanced Materials Research (Volumes 11-12)

Pages:

583-586

DOI:

https://doi.org/10.4028/www.scientific.net/AMR.11-12.583

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Online since:

February 2006

Authors:

Seong Min Choi, Takuya Matsunaga, Sung Ho Cheon, Sawao Honda, Shinobu Hashimoto, Hideo Awaji

Keywords:

Annealing, Dislocation, Fracture Toughness, Soaking Method, Toughening Mechanism

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© 2006 Trans Tech Publications Ltd. All Rights Reserved

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