Microstructures and Mechanical Properties of Fine-Scale Fibrous Alumina / Zirconia Bi-Phase Composite Fabricated by Co-Extrusion Process

Abstract:

A bundle of feedrod composed of ordinary arranged alumina and zirconia green rods was co-extruded through a 6:1 reduction die. The volume fraction of zirconia phase was varied from 10 to 88 vol%. After the first co-extrusion, the individual pieces were bundled and co-extruded again, reducing the lateral size of each phase and multiplying the number of continuous monofilaments. After a 3rd extrusion step and sintering at 1600oC, crack-free composites with a fiber diameter of ~50 μm were obtained for all compositions. The fracture toughness of the composites was improved by introducing fine second phase filaments into the matrix. The maximum fracture toughness of 6.2 MPa
m1/2 was attained in the 3rd co-extruded composite which consisted of 53 vol% alumina and 47 vol% zirconia. Bending strength of the composites was almost the same as that of the monolithic alumina regardless of the composition.

• Periodical: Key Engineering Materials (Volumes 317-318)
• Pages: 619-622
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.317-318.619
• Online since: August 2006
• Authors: Hiroyuki Miyazaki, Yuichi Yoshizawa, Kiyoshi Hirao
• Keywords: Aligned Microstructure, Alumina-Zirconia Composite, Extrusion, Mechanical Property

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