Premium
Determining the Critical Strain Energy Release Rate of Plasma‐Sprayed Coatings Using a Double‐Cantilever‐Beam Technique
Author(s) -
OSTOJIC P.,
McPHERSON R.
Publication year - 1988
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.1151-2916.1988.tb07542.x
Subject(s) - materials science , composite material , coating , fracture toughness , fractography , strain energy release rate , cantilever , adhesive , strain energy , beam (structure) , plasma , fracture mechanics , optics , structural engineering , layer (electronics) , finite element method , engineering , physics , quantum mechanics
A double‐cantilever‐beam (DCB) method for determining critical strain energy release rate (G Ic ) values from plasma‐sprayed coatings is described in detail. This approach, involving acoustic emission (AE) methodology, yielded up to 25 results per specimen and was successful in providing cohesive G Ic values for plasma‐sprayed coatings of Al 2 O 3 ‐2.5 wt% TiO 2 , Ni‐20 wt% Al, as well as two ostensibly identical, 99.5% commercially pure Al 2 O 3 coatings. Adhesive G Ic data from Al 2 O 3 ‐40 wt% TiO 2 coatings was also obtained. Results showed a G Ic dependence on crack length, and a number of possibilities, based on fractography, the AE response of the coatings during testing, and crack velocity measurements, are advanced to explain this occurrence. Differences in G Ic values between coatings were found to correlate with differences in powder/coating properties. The DCB method was also used to investigate batch differences and the effect on toughness of sealing an alumina coating. Problems associated with this method of testing are addressed.