A study of the structure of codeposited PVD coatings

Hampshire, J

Abstract

The structure of two-component coatings codeposited by magnetron sputter
ion plating was studied. This apparently simple topic has never been studied
systematically and has led to a number of unexpected and very interesting
results.
The systems that were studied included materials with 100% solid-solubility,
(titanium and zirconium) totally insoluble materials (chromium and copper)
and materials that can form intermetallic compounds (titanium and
aluminium). Variables studied included method of deposition, composition of
the coating and energy of ion bombardment during deposition. Two
approaches were used for the deposition process. These were multilayer
deposition from vertically opposed magnetrons and codeposition from coplanar
magnetrons, both using closed field magnetic arrays. Both methods are
fundamentally the same. It is the orientation and manipulation of the substrates
during the deposition process which leads to either a multilayer coating
structure or a codeposited homogeneous coating. The flexibility of the coating
technique was demonstrated and a greater understanding was gained of both
the structure and properties of alloy coatings and how these are influenced by
the deposition parameters in a magnetron sputtering system. The coating
structures were studied using SEM and XRD and their properties by different
mechanical tests. Prior studies in this field have shown that such coatings can
have unexpected properties. For example, energetic ion bombardment is
known to cause the production of 'non equilibrium' phases and can extend the
normal solubility range. Thus HCP Ti-Al coatings can be deposited which
would be expected to have good tribological properties. Properties such as
this have been studied and exploited for suitable applications. Further studies
showed how parameters such as ion current density are dependant on target
current and have a large influence on coating structures and properties. This is
all of importance to materials scientists, surface engineers and manufacturers
of coating equipment.

Citation

Hampshire, J. A study of the structure of codeposited PVD coatings. (Thesis). University of Salford

• Thesis Type: Thesis
• Deposit Date: Aug 18, 2021
• Additional Information: Funders : Engineering and Physical Sciences Research Council (EPSRC)
• Award Date: Jun 1, 2008