Competing fracture modes in brittle materials subject to concetrated cyclic loading in liquid environments: Trilayer structures

Ilja Hermann, Sanjit Bhowmick, Yu Zhang, Brian R. Lawn

Research output: Contribution to journalArticle

Abstract

A study is made of top-surface cracks induced in brittle trilayers by cyclic indentation with a hard sphere in water. The trilayers consist of an external brittle layer (veneer) fused to an inner stiff and hard ceramic support layer (core), in turn adhesively bonded to a thick compliant base (substrate). These structures are meant to simulate essential aspects of dental crowns, but their applicability extends to a range of engineering coating systems. The study follows on from like studies of brittle monoliths and brittle-plate/soft-substrate bilayers. Competing fracture modes in the outer brittle layer remain the same as before: outer and inner cone cracks and radial cracks, all of which form in the near-contact zone and propagate downward toward the veneer/core interface. Inner cone cracks and radial cracks are especially dangerous because of their relatively steep descent through the outer layer as well as enhanced susceptibility to mechanical fatigue. Experiments are conducted on model glass/alumina/polycarbonate systems, using video cameras to record the fracture evolution in the transparent glass layer in situ during testing. Each fracture mode can lead to failure, depending on the maximum contact load and other variables (plate thickness, sphere radius). The potentially beneficial role of a stiff intervening core is discussed, along with potentially deleterious side effects of residual thermal-expansion-mismatch stresses.

Original languageEnglish (US)
Pages (from-to)512-521
Number of pages10
JournalJournal of Materials Research
Volume21
Issue number2
DOIs
StatePublished - Feb 2006

Fingerprint

brittle materials
Brittleness
Cracks
cracks
veneers
Liquids
liquids
Veneers
polycarbonate
Cones
cones
contact loads
Glass
surface cracks
Aluminum Oxide
glass
descent
Video cameras
polycarbonates
Substrates

ASJC Scopus subject areas

  • Materials Science(all)

Cite this

Competing fracture modes in brittle materials subject to concetrated cyclic loading in liquid environments : Trilayer structures. / Hermann, Ilja; Bhowmick, Sanjit; Zhang, Yu; Lawn, Brian R.

In: Journal of Materials Research, Vol. 21, No. 2, 02.2006, p. 512-521.

Research output: Contribution to journalArticle

@article{07b1ca8bfffa434d953e04a4bebfbb46,
title = "Competing fracture modes in brittle materials subject to concetrated cyclic loading in liquid environments: Trilayer structures",
abstract = "A study is made of top-surface cracks induced in brittle trilayers by cyclic indentation with a hard sphere in water. The trilayers consist of an external brittle layer (veneer) fused to an inner stiff and hard ceramic support layer (core), in turn adhesively bonded to a thick compliant base (substrate). These structures are meant to simulate essential aspects of dental crowns, but their applicability extends to a range of engineering coating systems. The study follows on from like studies of brittle monoliths and brittle-plate/soft-substrate bilayers. Competing fracture modes in the outer brittle layer remain the same as before: outer and inner cone cracks and radial cracks, all of which form in the near-contact zone and propagate downward toward the veneer/core interface. Inner cone cracks and radial cracks are especially dangerous because of their relatively steep descent through the outer layer as well as enhanced susceptibility to mechanical fatigue. Experiments are conducted on model glass/alumina/polycarbonate systems, using video cameras to record the fracture evolution in the transparent glass layer in situ during testing. Each fracture mode can lead to failure, depending on the maximum contact load and other variables (plate thickness, sphere radius). The potentially beneficial role of a stiff intervening core is discussed, along with potentially deleterious side effects of residual thermal-expansion-mismatch stresses.",
author = "Ilja Hermann and Sanjit Bhowmick and Yu Zhang and Lawn, {Brian R.}",
year = "2006",
month = "2",
doi = "10.1557/jmr.2006.0056",
language = "English (US)",
volume = "21",
pages = "512--521",
journal = "Journal of Materials Research",
issn = "0884-2914",
publisher = "Materials Research Society",
number = "2",

}

TY - JOUR

T1 - Competing fracture modes in brittle materials subject to concetrated cyclic loading in liquid environments

T2 - Trilayer structures

AU - Hermann, Ilja

AU - Bhowmick, Sanjit

AU - Zhang, Yu

AU - Lawn, Brian R.

PY - 2006/2

Y1 - 2006/2

N2 - A study is made of top-surface cracks induced in brittle trilayers by cyclic indentation with a hard sphere in water. The trilayers consist of an external brittle layer (veneer) fused to an inner stiff and hard ceramic support layer (core), in turn adhesively bonded to a thick compliant base (substrate). These structures are meant to simulate essential aspects of dental crowns, but their applicability extends to a range of engineering coating systems. The study follows on from like studies of brittle monoliths and brittle-plate/soft-substrate bilayers. Competing fracture modes in the outer brittle layer remain the same as before: outer and inner cone cracks and radial cracks, all of which form in the near-contact zone and propagate downward toward the veneer/core interface. Inner cone cracks and radial cracks are especially dangerous because of their relatively steep descent through the outer layer as well as enhanced susceptibility to mechanical fatigue. Experiments are conducted on model glass/alumina/polycarbonate systems, using video cameras to record the fracture evolution in the transparent glass layer in situ during testing. Each fracture mode can lead to failure, depending on the maximum contact load and other variables (plate thickness, sphere radius). The potentially beneficial role of a stiff intervening core is discussed, along with potentially deleterious side effects of residual thermal-expansion-mismatch stresses.

AB - A study is made of top-surface cracks induced in brittle trilayers by cyclic indentation with a hard sphere in water. The trilayers consist of an external brittle layer (veneer) fused to an inner stiff and hard ceramic support layer (core), in turn adhesively bonded to a thick compliant base (substrate). These structures are meant to simulate essential aspects of dental crowns, but their applicability extends to a range of engineering coating systems. The study follows on from like studies of brittle monoliths and brittle-plate/soft-substrate bilayers. Competing fracture modes in the outer brittle layer remain the same as before: outer and inner cone cracks and radial cracks, all of which form in the near-contact zone and propagate downward toward the veneer/core interface. Inner cone cracks and radial cracks are especially dangerous because of their relatively steep descent through the outer layer as well as enhanced susceptibility to mechanical fatigue. Experiments are conducted on model glass/alumina/polycarbonate systems, using video cameras to record the fracture evolution in the transparent glass layer in situ during testing. Each fracture mode can lead to failure, depending on the maximum contact load and other variables (plate thickness, sphere radius). The potentially beneficial role of a stiff intervening core is discussed, along with potentially deleterious side effects of residual thermal-expansion-mismatch stresses.

UR - http://www.scopus.com/inward/record.url?scp=33644505154&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33644505154&partnerID=8YFLogxK

U2 - 10.1557/jmr.2006.0056

DO - 10.1557/jmr.2006.0056

M3 - Article

VL - 21

SP - 512

EP - 521

JO - Journal of Materials Research

JF - Journal of Materials Research

SN - 0884-2914

IS - 2

ER -