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Influence of Cu 2 O and CuAlO 2 Interphases on Crack Propagation at Cu/α‐Al 2 O 3 Interfaces
Author(s) -
Reimanis Ivar E.,
Trumble Kevin P.,
Rogers Kirk A.,
Dalgleish Brian James
Publication year - 1997
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.1151-2916.1997.tb02847.x
Subject(s) - interphase , materials science , fracture mechanics , brittleness , composite material , crack growth resistance curve , fracture toughness , fracture (geology) , diffusion , crack closure , thermodynamics , genetics , physics , biology
In‐situ crack‐propagation experiments, in conjunction with thermochemical experiments, have been used to examine the role of discontinuous interphases on the fracture behavior of solid‐state diffusion‐bonded Cu/α‐Al 2 O 3 couples. Clean, interphase‐free interfaces exhibit crack extension by brittle decohesion at the crack tip at an initiation fracture energy of 125 J/m 2 . Crack propagation is characterized by an increase in the fracture energy with increases in the crack length ( R ‐curve behavior). When interfacial chemical reaction products are present, the crack growth is altered, depending on the characteristics of the interphase. The presence of Cu 2 O needles results in preferential debonding along the Cu 2 O/Al 2 O 3 interface. On the other hand, finer CuAlo 2 needles visibly impede crack propagation and result in a higher interface initiation fracture energy (}190 J/m 2 ) than that of the interphase‐free interface. The effects of the Cu 2 O and CuAlo 2 phases on the fracture energy are discussed.