Effect of Al and ZrO2 on Sinterability and Mechanical Properties of B4C

Abstract:

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Ceramics composites of B4C matrix with 5 wt% Al and various amount of ZrO2 additives were pressureless sintered under vacuum at 2250 °C for 60 min. Density, hardness, flexural strength and microstructure of the specimens were measured and characterized. Densities above 97% theoretical density (TD) were determined in the samples prepared with the addition of 8 wt% ZrO2 and 5 wt% Al, compared to 86% TD for single-phase B4C. X-ray diffraction analysis showed that B2O3 (impurity in B4C) was eliminated and new phases (ZrB2 and B4C1-x) were formed in the sintered samples, suggesting that in situ reactions between B4C/B2O3 and Al/ZrO2 happened during sintering process. It was showed that the elimination of B2O3 and the forming of boron rich solution of B4C1-x significantly improved the sinterability of B4C matrix ceramics, and consequently enhanced the densification rate greatly. The flexural strength and Vickers hardness of the sintered samples with addition of 8 wt% ZrO2 and 5 wt% Aluminum reached the value of 560 MPa and 30.2 GPa respectively, much higher than those of single-phase B4C ceramics.

Info:

Periodical:

Advanced Materials Research (Volumes 160-162)

Edited by:

Guojun Zhang and Jessica Xu

Pages:

1494-1497

DOI:

10.4028/www.scientific.net/AMR.160-162.1494

Citation:

W. S. Lin and L. He, "Effect of Al and ZrO2 on Sinterability and Mechanical Properties of B4C", Advanced Materials Research, Vols. 160-162, pp. 1494-1497, 2011

Online since:

November 2010

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Price:

$35.00

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