Hard Chrome Plating Alternatives - Vacuum PVD
Metal nitrides deposited
by physical vapor deposition (PVD) or chemical vapor
deposition (CVD) are very hard and wear resistant. They are
widely used in the cutting tool industry and for “lifetime
warranty” coatings on locksets and faucets, but they are
little used in place of hard chrome especially in DoD.
There are several reasons for this, primarily:
-
PVD coatings require
the use of complex vacuum equipment
-
They are very thin
and cannot be used for rebuilding worn equipment
-
They have no
commercial or military specifications
There are a few
exceptions to the DoD use of PVD technology
-
IVD Aluminum (Ivadizing) is commonly used
as a Cd alternative, and a number of depots have IVD
equipment
-
Marshall Labs has developed equipment to
sputter Al onto IDs of landing gear and similar items.
The equipment, called Plug and Coat, is installed on an
IVD chamber at Hill AFB
-
Benet Labs has developed equipment to
sputter Ta onto the interiors of large gun barrels as an
alternative to hard chrome.
Hard chrome alternatives summary – vacuum coating (primary
alternatives in blue)
|
Alternative |
Compliance |
Usage |
Notes |
|
PVD hard
coatings, TiN, CrN, B4C, etc. and Ta.
|
RoHS, WEEE, ELV, OSHA Cr |
Large gun barrel IDs (Ta) |
Not capable of build-up |
|
CVD hard coatings, TiN, WC, etc. |
RoHS, WEEE, ELV, OSHA Cr |
Industrial cutting tools |
Not capable of build-up. Best for small, high-value
components. High deposition temperature |
|
Diamond and diamond-like coatings |
RoHS, WEEE, ELV, OSHA Cr |
Automotive fuel injectors, other applications
requiring lubricity and wear resistance |
Hard and lubricious, brittle. Good for small
components |
Plug and Coat system in operation.
Gun barrel PVD coating system - Benet Labs
|
