STRENGTH OF A CSPHERE FLEXURE SPECIMEN
Abstract
A 'CSphere' flexure strength specimen geometry was conceived and developed to measure a relevant strength of bearinggrade Si{sub 3}N{sub 4} balls and to relate that to surfacelocated strengthlimiting flaws and to ultimately link those flaw populations to rolling contact fatigue performance. A slot was machined into the balls to a set depth to produce the Csphere geometry. Csphere specimens were then diametrally compressed to produce a monotonically increasing flexure or hoop tensile stress at their surface that caused their fracture. The strength was determined using the combination of failure load, Csphere geometry, and FEA, and the stress field was used to determine Csphere effective areas and effective volumes as a function of Weibull modulus. A description of the specimen and the aforementioned analysis are provided and a comparison of Csphere flexure strength distributions of two bearing grade Si{sub 3}N{sub 4} materials (NBD200 and SN101C) is given.
 Authors:
 ORNL
 University of Wisconsin, Platteville
 Publication Date:
 Research Org.:
 Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); High Temperature Materials Laboratory
 Sponsoring Org.:
 USDOE Office of Energy Efficiency and Renewable Energy (EERE)
 OSTI Identifier:
 931246
 DOE Contract Number:
 DEAC0500OR22725
 Resource Type:
 Conference
 Resource Relation:
 Conference: 30th International Conference and Exposition on Advanced Ceramics and Composites, Cocoa Beach, FL, USA, 20060122, 20060127
 Country of Publication:
 United States
 Language:
 English
 Subject:
 36 MATERIALS SCIENCE; SILICON NITRIDES; BALL BEARINGS; FLEXURAL STRENGTH; DESTRUCTIVE TESTING; DEFECTS; PERFORMANCE; FINITE ELEMENT METHOD
Citation Formats
Wereszczak, Andrew A, Wang, Wei, Jadaan, Osama M., Lance, Michael J, and Lin, HuaTay. STRENGTH OF A CSPHERE FLEXURE SPECIMEN. United States: N. p., 2007.
Web.
Wereszczak, Andrew A, Wang, Wei, Jadaan, Osama M., Lance, Michael J, & Lin, HuaTay. STRENGTH OF A CSPHERE FLEXURE SPECIMEN. United States.
Wereszczak, Andrew A, Wang, Wei, Jadaan, Osama M., Lance, Michael J, and Lin, HuaTay. Mon .
"STRENGTH OF A CSPHERE FLEXURE SPECIMEN". United States.
doi:.
@article{osti_931246,
title = {STRENGTH OF A CSPHERE FLEXURE SPECIMEN},
author = {Wereszczak, Andrew A and Wang, Wei and Jadaan, Osama M. and Lance, Michael J and Lin, HuaTay},
abstractNote = {A 'CSphere' flexure strength specimen geometry was conceived and developed to measure a relevant strength of bearinggrade Si{sub 3}N{sub 4} balls and to relate that to surfacelocated strengthlimiting flaws and to ultimately link those flaw populations to rolling contact fatigue performance. A slot was machined into the balls to a set depth to produce the Csphere geometry. Csphere specimens were then diametrally compressed to produce a monotonically increasing flexure or hoop tensile stress at their surface that caused their fracture. The strength was determined using the combination of failure load, Csphere geometry, and FEA, and the stress field was used to determine Csphere effective areas and effective volumes as a function of Weibull modulus. A description of the specimen and the aforementioned analysis are provided and a comparison of Csphere flexure strength distributions of two bearing grade Si{sub 3}N{sub 4} materials (NBD200 and SN101C) is given.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}

A "Csphere" flexure strength specimen geometry was conceived and developed to measure the hoop tensile strength of bearinggrade silicon nitride (Si3N4) balls. Because such a strength can be measured, the important study of surfacelocated strengthlimiting flaws in ceramic sphere is also enabled with this specimen. A slot is machined into the balls to a set depth to produce the Csphere geometry. A simple, monotonically increasing uniaxial compressive force produces a hoop tensile stress at the Csphere's outer surface that ultimately initiates fracture. The strength is determined using the combination of failure load, Csphere geometry, and finite element analysis. Additionally, themore »

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