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Viscoelastic Effects in a Phosphate Glass‐Metal Seal
Author(s) -
Chambers R. S.,
Gerstle Frank P.,
Monroe S. L.
Publication year - 1989
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.1151-2916.1989.tb06246.x
Subject(s) - viscoelasticity , materials science , thermal expansion , seal (emblem) , ultimate tensile strength , composite material , stress relaxation , residual stress , relaxation (psychology) , stress (linguistics) , thermal , creep , thermodynamics , art , social psychology , psychology , visual arts , linguistics , philosophy , physics
A family of phosphate glasses has been developed with thermal expansion behavior in the elastic range that nearly matches the response of 304 stainless steel. Attempts to make concentric pin‐shell seals consistently have yielded fractures between 400° and 300°C during cooling. Elastic stress analyses which neglect glass transitional behavior and utilize constant glassy (“elastic”) thermal expansion coefficients predict a residual stress state that is compressive. However, viscoelastic computations which include the effects of structural relaxation during glass transtion show that tensile stresses sufficient to cause failure arise during cooldown of the seal.