Title: Influences of nanometre Y2O3 and Yb2O3 additives on structure and properties of α/β-Sialon ceramics prepared by spark plasma sintering

Authors: Yucheng Zhao; Wenna Zhang; Qinggang Chen; Mingzhi Wang; Wencan Song; Lei Wang

Addresses: Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, Hebei 066004, China ' Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, Hebei 066004, China ' Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, Hebei 066004, China ' Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, Hebei 066004, China ' College of Electrical Engineering, Yanshan University, Qinhuangdao, Hebei 066004, China ' Qinhuangdao Institute of Technology, Qinhuangdao, Hebei 066100, China

Abstract: Using micrometre α-Si3N4, micrometre AlN, and nanometre Al2O3 powders as starting materials, with nanometre Y2O3, Yb2O3 or Y2O3 + Yb2O3 as sintering additives, multiphase Sialon ceramics were prepared by spark plasma sintering. Influences of different sintering additives on the structure and properties of α/β-Sialon ceramics were discussed in this paper. Sintered specimens were characterised by X-ray diffraction and scanning electron microscopy. Hardness and fracture toughness were determined by Vickers indentation method. The flexural strength was tested by three-point bending method and density was measured by use of Archimedes's principle. The results showed that Yb2O3 additive had more effect on the precipitation of α-Sialon phase than Y2O3, and the flexural strength and fracture toughness of the specimen with Yb2O3 additive were 583.04 MPa and 4.84 MPa.m1/2, respectively.

Keywords: alpha-Sialon; beta-Sialon; sintering additives; spark plasma sintering; SPS; yttrium oxide; yttria; nanotechnology; Y2O3; ceramics; hardness; fracture toughness; flexural strength.

DOI: 10.1504/IJNM.2013.056065

International Journal of Nanomanufacturing, 2013 Vol.9 No.3/4, pp.387 - 394

Received: 04 Dec 2012
Accepted: 20 Feb 2013

Published online: 31 Mar 2014 *

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