Premium
The very beginning of plastic deformation during sliding contact on amorphous carbon coatings
Author(s) -
Wienss A.,
Jacoby B.
Publication year - 2004
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.1884
Subject(s) - materials science , composite material , deformation (meteorology) , amorphous solid , amorphous carbon , diamond like carbon , surface roughness , nanometre , surface finish , carbon fibers , radius , nanotechnology , thin film , composite number , crystallography , chemistry , computer security , computer science
Various thin amorphous carbon coatings (5–12 nm) as well as silicon oxide surfaces were scratched by means of a diamond tipped cantilever, simulating a hard scratching particle with a radius of 80–100 nm. Using advanced image processing, ultra‐shallow scratches with depths of only 1–2 Å can be visualized and analysed, even on surfaces with RMS roughness values up to 10 Å. This enables us to evaluate the conditions in terms of local pressure and speed under which plastic deformation initially takes place. Different deformation mechanisms could be deduced for different types of surfaces. Repeated measurements suggest a local compression of the amorphous low‐density structures underneath the tip. Using a simple force balance model, it can be estimated that in the initial phase of plastic deformation, the lateral force acting on the tip is dominated by the friction force and not yet by a ploughing term. This sub‐nanometre scratching technique has been developed for the mechanical characterization and optimization of ultra‐thin amorphous carbon coatings used as protective layers in hard disk drives. Copyright © 2004 John Wiley & Sons, Ltd.