TY - JOUR
T1 - Evaluation of crack bridging characteristics in carbon nanotube/alumina composites using single fiber pullout testing method
AU - Yamamoto, Go
AU - Shirasu, Keiichi
AU - Takagi, Toshiyuki
AU - Hashida, Toshiyuki
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2011
Y1 - 2011
N2 - The crack bridging behavior of multi-walled carbon nanotube-reinforced alumina matrix composites has been investigated using a single fiber pullout testing method. Contradictory to the conventional understanding (which have reported that pullout phenomena evidently occurred in the bulk nanotube-reinforced alumina composites), the pullout experiments using an in situ SEM method with a nanomanipulator system demonstrated that strong load transfer was revealed, and no pullout behavior was observed for all 15 MWCNTs. The MWCNTs, rather than pulling out from the alumina matrix, broke in the outer-shells and the inner section was pulled away, leaving the outer-shells of the fragment in the matrix. This implies that tougher ceramics with MWCNT can be obtained by creating the appropriate interaction between the matrix and MWCNT: not too week but also not too strong to permit an adequate load transfer between the two parts and thus a consequent pulling out without breakage of MWCNT. Our finding suggests important implications for the design of tougher ceramic composites with MWCNTs. The important factor for such tougher ceramic composites will thus be the use of 'strong' MWCNTs having higher mechanical performance (as well as a good dispersion in the matrix).
AB - The crack bridging behavior of multi-walled carbon nanotube-reinforced alumina matrix composites has been investigated using a single fiber pullout testing method. Contradictory to the conventional understanding (which have reported that pullout phenomena evidently occurred in the bulk nanotube-reinforced alumina composites), the pullout experiments using an in situ SEM method with a nanomanipulator system demonstrated that strong load transfer was revealed, and no pullout behavior was observed for all 15 MWCNTs. The MWCNTs, rather than pulling out from the alumina matrix, broke in the outer-shells and the inner section was pulled away, leaving the outer-shells of the fragment in the matrix. This implies that tougher ceramics with MWCNT can be obtained by creating the appropriate interaction between the matrix and MWCNT: not too week but also not too strong to permit an adequate load transfer between the two parts and thus a consequent pulling out without breakage of MWCNT. Our finding suggests important implications for the design of tougher ceramic composites with MWCNTs. The important factor for such tougher ceramic composites will thus be the use of 'strong' MWCNTs having higher mechanical performance (as well as a good dispersion in the matrix).
KW - Carbon Nanotubes
KW - Ceramics
KW - Composite Material
KW - Crack Bridging Behavior
KW - Single Fiber Pullout Tests
UR - http://www.scopus.com/inward/record.url?scp=84856481279&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84856481279&partnerID=8YFLogxK
U2 - 10.1299/kikaia.77.779
DO - 10.1299/kikaia.77.779
M3 - Article
AN - SCOPUS:84856481279
VL - 77
SP - 779
EP - 783
JO - Nihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A
JF - Nihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A
SN - 0387-5008
IS - 777
ER -