Strength-toughness relations in sintered and isostatically hot-pressed ZrO/sub 2/-toughened Al/sub 2/O/sub 3/

Journal Article · Sat Mar 01 00:00:00 EST 1986 · J. Am. Ceram. Soc.; (United States)

OSTI ID:5850826

Hori, S; Yoshimura, M; Somiya, S

The fracture toughness of fine-grained undoped ZrO/sub 2/-toughened Al/sub 2/O/sub 3/ (ZTA) was essentially unchanged by post-sintering hot isostatic pressing and increased monotonically with ZrO/sub 2/ additions up to 25 wt%. The strength of ZTA with 5 to 15 wt% tetragonal ZrO/sub 2/, which depended monotonically on the amount of ZrO/sub 2/ present before hot isostatic pressing, was increased by pressing but became almost constant between 5 and 15 wt% ZrO/sub 2/ addition. The strength appeared to be controlled by pores before pressing and by surface flaws after pressing; the size of flaws after pressing increased with ZrO/sub 2/ content. The strength of ZTA containing mostly monoclinic ZrO/sub 2/ (20 to 25 wt%) remained almost constant despite the noticeable density increase upon hot isostatic pressing because the strength was controlled by preexisting microcracks whose extent did not change on postsintering pressing. These strength-toughness relations in sintered and isostatically hot-pressed ZTA are explained on the basis of R-curve behavior. The importance of the contribution of microcracks to the toughness of ZTA is emphasized.

• Research Organization: Kureha Chemical Industry Co., Ltd., 16 Ochiai, Nishikimachi, Iwaki-shi, Fukushima 974
• OSTI ID: 5850826
• Journal Information: J. Am. Ceram. Soc.; (United States), Vol. 69:3
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
FRACTURE PROPERTIES
HOT PRESSING
ZIRCONIUM OXIDES
CRACKS
DEFECTS
DENSITY
POROSITY
QUANTITY RATIO
SINTERED MATERIALS
ALUMINIUM COMPOUNDS
CHALCOGENIDES
FABRICATION
MATERIALS
MATERIALS WORKING
MECHANICAL PROPERTIES
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PRESSING
TRANSITION ELEMENT COMPOUNDS
ZIRCONIUM COMPOUNDS
360203* - Ceramics
Cermets
& Refractories- Mechanical Properties
360201 - Ceramics
Cermets
& Refractories- Preparation & Fabrication