Acoustic emission studies of alumina-13% titania free-standing forms during four-point bend tests

Chung Kwei Lin, Christopher C. Berndt, Sang Ha Leigh, Kenji Murakami

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

Free-standing alumina-13% titania samples were manufactured with a water-stabilized plasma spray gun to a thickness of ∼5 mm. A thin layer of aluminum was arc sprayed prior to depositing the thick coating and etched away using hydrochloric acid. The so-obtained free-standing plate was cut into four-point-bend-test specimens with dimensions of ∼5 mm × 5 mm × 50 mm. The assprayed material consisted of a supersaturated solid solution, where titania was frozen inside the alumina matrix. Heat treatment was performed at 1450°C for 24 h and then at 1100°C for another 24 h. After heat treatment, titania precipitates were observed. The major phases of the assprayed and heat-treated samples were γ- and α-alumina, respectively. The porosity was ∼10% for as-sprayed samples; this value was reduced to ∼3% after heat treatment. Four-point bend tests were performed on the assprayed and heat-treated specimens in cross-section and in-plane directions. An acoustic emission technique was used to examine the cracking during the tests in situ. Microcracking prior to failure was observed for as-sprayed samples that were tested in the cross-section direction. However, when tested in the in-plane direction, catastrophic failure with less evidence of microcracking occurred. For heat-treated specimens, microcracks were usually observed when tests were performed in either of the orientations. Energy and amplitude distributions for each testing condition were examined. These distributions changed after heat treatment; however, no significant differences were distinguished when tests were performed in the cross-section or in-plane directions.

Original languageEnglish
Pages (from-to)2382-2394
Number of pages13
JournalJournal of the American Ceramic Society
Volume80
Issue number9
Publication statusPublished - Sep 1997
Externally publishedYes

Fingerprint

Aluminum Oxide
Acoustic emissions
Alumina
Titanium
Heat treatment
Microcracking
Spray guns
Hydrochloric Acid
Microcracks
Hydrochloric acid
Aluminum
Precipitates
Solid solutions
Porosity
Plasmas
Coatings
Direction compound
titanium dioxide
Water
Testing

ASJC Scopus subject areas

  • Ceramics and Composites

Cite this

Acoustic emission studies of alumina-13% titania free-standing forms during four-point bend tests. / Lin, Chung Kwei; Berndt, Christopher C.; Leigh, Sang Ha; Murakami, Kenji.

In: Journal of the American Ceramic Society, Vol. 80, No. 9, 09.1997, p. 2382-2394.

Research output: Contribution to journalArticle

Lin, Chung Kwei ; Berndt, Christopher C. ; Leigh, Sang Ha ; Murakami, Kenji. / Acoustic emission studies of alumina-13% titania free-standing forms during four-point bend tests. In: Journal of the American Ceramic Society. 1997 ; Vol. 80, No. 9. pp. 2382-2394.
@article{65a2ba7e86914cb29b1d896e64232882,
title = "Acoustic emission studies of alumina-13{\%} titania free-standing forms during four-point bend tests",
abstract = "Free-standing alumina-13{\%} titania samples were manufactured with a water-stabilized plasma spray gun to a thickness of ∼5 mm. A thin layer of aluminum was arc sprayed prior to depositing the thick coating and etched away using hydrochloric acid. The so-obtained free-standing plate was cut into four-point-bend-test specimens with dimensions of ∼5 mm × 5 mm × 50 mm. The assprayed material consisted of a supersaturated solid solution, where titania was frozen inside the alumina matrix. Heat treatment was performed at 1450°C for 24 h and then at 1100°C for another 24 h. After heat treatment, titania precipitates were observed. The major phases of the assprayed and heat-treated samples were γ- and α-alumina, respectively. The porosity was ∼10{\%} for as-sprayed samples; this value was reduced to ∼3{\%} after heat treatment. Four-point bend tests were performed on the assprayed and heat-treated specimens in cross-section and in-plane directions. An acoustic emission technique was used to examine the cracking during the tests in situ. Microcracking prior to failure was observed for as-sprayed samples that were tested in the cross-section direction. However, when tested in the in-plane direction, catastrophic failure with less evidence of microcracking occurred. For heat-treated specimens, microcracks were usually observed when tests were performed in either of the orientations. Energy and amplitude distributions for each testing condition were examined. These distributions changed after heat treatment; however, no significant differences were distinguished when tests were performed in the cross-section or in-plane directions.",
author = "Lin, {Chung Kwei} and Berndt, {Christopher C.} and Leigh, {Sang Ha} and Kenji Murakami",
year = "1997",
month = "9",
language = "English",
volume = "80",
pages = "2382--2394",
journal = "Journal of the American Ceramic Society",
issn = "0002-7820",
publisher = "Wiley-Blackwell",
number = "9",

}

TY - JOUR

T1 - Acoustic emission studies of alumina-13% titania free-standing forms during four-point bend tests

AU - Lin, Chung Kwei

AU - Berndt, Christopher C.

AU - Leigh, Sang Ha

AU - Murakami, Kenji

PY - 1997/9

Y1 - 1997/9

N2 - Free-standing alumina-13% titania samples were manufactured with a water-stabilized plasma spray gun to a thickness of ∼5 mm. A thin layer of aluminum was arc sprayed prior to depositing the thick coating and etched away using hydrochloric acid. The so-obtained free-standing plate was cut into four-point-bend-test specimens with dimensions of ∼5 mm × 5 mm × 50 mm. The assprayed material consisted of a supersaturated solid solution, where titania was frozen inside the alumina matrix. Heat treatment was performed at 1450°C for 24 h and then at 1100°C for another 24 h. After heat treatment, titania precipitates were observed. The major phases of the assprayed and heat-treated samples were γ- and α-alumina, respectively. The porosity was ∼10% for as-sprayed samples; this value was reduced to ∼3% after heat treatment. Four-point bend tests were performed on the assprayed and heat-treated specimens in cross-section and in-plane directions. An acoustic emission technique was used to examine the cracking during the tests in situ. Microcracking prior to failure was observed for as-sprayed samples that were tested in the cross-section direction. However, when tested in the in-plane direction, catastrophic failure with less evidence of microcracking occurred. For heat-treated specimens, microcracks were usually observed when tests were performed in either of the orientations. Energy and amplitude distributions for each testing condition were examined. These distributions changed after heat treatment; however, no significant differences were distinguished when tests were performed in the cross-section or in-plane directions.

AB - Free-standing alumina-13% titania samples were manufactured with a water-stabilized plasma spray gun to a thickness of ∼5 mm. A thin layer of aluminum was arc sprayed prior to depositing the thick coating and etched away using hydrochloric acid. The so-obtained free-standing plate was cut into four-point-bend-test specimens with dimensions of ∼5 mm × 5 mm × 50 mm. The assprayed material consisted of a supersaturated solid solution, where titania was frozen inside the alumina matrix. Heat treatment was performed at 1450°C for 24 h and then at 1100°C for another 24 h. After heat treatment, titania precipitates were observed. The major phases of the assprayed and heat-treated samples were γ- and α-alumina, respectively. The porosity was ∼10% for as-sprayed samples; this value was reduced to ∼3% after heat treatment. Four-point bend tests were performed on the assprayed and heat-treated specimens in cross-section and in-plane directions. An acoustic emission technique was used to examine the cracking during the tests in situ. Microcracking prior to failure was observed for as-sprayed samples that were tested in the cross-section direction. However, when tested in the in-plane direction, catastrophic failure with less evidence of microcracking occurred. For heat-treated specimens, microcracks were usually observed when tests were performed in either of the orientations. Energy and amplitude distributions for each testing condition were examined. These distributions changed after heat treatment; however, no significant differences were distinguished when tests were performed in the cross-section or in-plane directions.

UR - http://www.scopus.com/inward/record.url?scp=0031237988&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0031237988&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0031237988

VL - 80

SP - 2382

EP - 2394

JO - Journal of the American Ceramic Society

JF - Journal of the American Ceramic Society

SN - 0002-7820

IS - 9

ER -