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Direct Observation of Crack Tip Stress Field Using the Mechanoluminescence of SrAl 2 O 4 :(Eu,Dy,Nd)
Author(s) -
Sohn KeeSun,
Seo Soo Yeon,
Kwon Yong Nam,
Park Hee Dong
Publication year - 2002
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.1151-2916.2002.tb00158.x
Subject(s) - mechanoluminescence , materials science , luminescence , phosphor , composite material , doping , analytical chemistry (journal) , optoelectronics , chemistry , environmental chemistry
The present investigation aims at visualizing the crack tip stress field using a mechanoluminescence material. The well‐known compound SrAl 2 O 4 :Eu 2+ was adopted as a mechanoluminescence material. Two more trivalent rare‐earth elements such as Dy and Nd were taken into consideration as codopants to provide the appropriate trap levels. Samples of a variety of compositions were prepared by varying Eu 2+ , Dy 3+ , and Nd 3+ doping contents, for which the combinatorial chemistry method was used. In order to search for the optimum composition for the highest mechanoluminescence, the luminescence induced by a compressive loading was monitored by using a specially designed pressing device including a CCD camera. In parallel, a compact tension specimen was prepared by mixing the luminescence powders of optimum composition and epoxy resin. Crack initiation from the mechanically machined sharp notch tip and its growth during loading were found to be associated with the extent of light emission from SrAl 2 O 4 .