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Relationship Between Microstructures and Material Properties of Novel Fibrous Al 2 O 3 –(m‐ZrO 2 )/t‐ZrO 2 Composites
Author(s) -
Lee ByongTaek,
Jang DongHwi,
Kang InCheol,
Lee ChiWoo
Publication year - 2005
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2005.00519.x
Subject(s) - materials science , composite material , microstructure , fracture toughness , intergranular corrosion , composite number , monoclinic crystal system , extrusion , intergranular fracture , tetragonal crystal system , fracture (geology) , phase (matter) , crystal structure , crystallography , chemistry , organic chemistry
Novel fibrous Al 2 O 3 –(m‐ZrO 2 )/t‐ZrO 2 (m, monoclinic; t, tetragonal) composites having a core/shell structure were fabricated by multi‐extrusion, and their microstructures and material properties were investigated depending on the number of extrusions. The composites acquired a homogeneously fine fibrous structure as the number of extrusions increased. The bending strength and fracture toughness increased remarkably as the number of extrusions increased. In the fracture surface of the second passed composite, an Al 2 O 3 –(m‐ZrO 2 ) core region appeared, flat type, although some local regions existed with an intergranular fracture. However, the fracture mode of the t‐ZrO 2 region was of intergranular type having a sharp and rough surface. In the composite made by the fifth passed extrusion, the fracture strength and toughness values were high at about 665 MPa and 9.6 MPa·m 1/2 , respectively. The main fracture mode was a typical intergranular mode having a rough fracture surface, and the main multi‐toughening was because of mechanisms such as crack bridging, microcracking, and phase transformation.