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Unusual Indentation Behavior of Alkali Metaphosphate Glass Above Glass Transition Temperature
Author(s) -
Endo Jun,
Inaba Seiji,
Muto Hiroyuki,
Ito Setsuro
Publication year - 2017
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/jace.14489
Subject(s) - metaphosphate , materials science , glass transition , indentation , composite material , deformation (meteorology) , phosphate glass , displacement (psychology) , relaxation (psychology) , stress (linguistics) , alkali metal , creep , mineralogy , polymer , chemistry , phosphate , doping , psychology , social psychology , linguistics , philosophy , optoelectronics , organic chemistry , psychotherapist
The mixed alkali metaphosphate glass 12.5Li 2 O–12.5Na 2 O–12.5K 2 O–12.5Cs 2 O–50P 2 O 5 (mol%) compressed under uniaxial stress shows unusually large recovery of its shape during heating above its glass transition temperature ( T g ). To clarify the mechanism, the viscous, elastic, and plastic behavior of the metaphosphate glass was investigated with the depth‐sensing indentation method. From the load‐displacement ( P – h ) curves of the glass, a large recovery of the depth displacement was found during unloading above T g . By analyzing the P – h curves with a viscous–elastic–plastic model, the large recovery was concluded to be due to larger elastic deformation than viscous deformation even above T g . The phenomenon can be attributed to relaxation to the randomly oriented ‐P–O–P– chain structure from the oriented chain structure formed under stress in the metaphosphate glass .