Ed. Mccarty et Sa. Hackney, LOCAL INTERFACE RESPONSE TO DISLOCATION STRAIN FIELDS AT THE AL SIO2 AND AL/C BOUNDARY REGION/, Materials science & engineering. A, Structural materials: properties, microstructure and processing, 196(1-2), 1995, pp. 119-128
This work presents a transmission electron microscopy study of the loc
al bimaterial interface response to applied stress. The intersection o
f a dislocation moving at some angle to the incoherent bimaterial inte
rface with the interface results in the creation of a dislocation line
defect (an extrinsic defect) at the interface. The intersection of th
e strain field of these defects with the interface is analogous to per
forming a tensile test or a shear test on the interface, but on the at
omic scale. This paper will examine how the mechanical stability of th
is type of extrinsic defect can be a measure of the strength of the in
terface. A measure of this stability can be performed by examining the
degree of interfacial defect relaxation, as determined by the diffrac
tion contrast in the transmission electron microscope under an applied
stress. We compare in this work the interface between sputter-cleaned
Al and sputter-deposited, amorphous SiO2 and the interface between sp
utter-cleaned Al and sputter-deposited, amorphous C. It is found that
the amorphous carbon/aluminum interface region is much weaker than the
amorphous silica/aluminum interface region. A qualitative measure of
the relative strengths of the two interface regions is possible by mea
suring the difference in the amount of extrinsic defect relaxation. A
quantitative measurement of the interfacial shear strength can be made
by an indirect determination of the shear stress as the interface whe
n extrinsic defect relaxation occurs.