|
Frequently Asked
Questions:
-
Can we mask off?
PVD
is a line of sight process so masking is typically unnecessary.
Parts can be masked if required.
-
What is the coating thickness?
Typically PVD coatings
are 3 - 5 microns (1 - 2 ten thousandths of an inch).
-
Can Internal Diameter's be coated?
Yes, but there are
some depth limitations for PVD coatings.
-
What are the coefficients of friction
for coatings?
TiN
0.65
TiCN
0.45
CrN
0.55
TiAlN
0.42
ZrN
0.60
Select coatings based on total in use properties.
-
What is the processing temperature?
400o
F - 900o F controlled by part temperature for PVD.
-
What are the typical processes steps
in applying a coating?
Ultrasonic
pre-cleaning of the components.
Vacuum
(10-5 Torr - 10-6 Torr)
Glow Discharge
(Reverse Plasma Etch)
High Negative
Potential (between parts/anode and evaporation/cathode
source) 400 Volts
Argon
gas is ionized via an electric discharge (plasma)
Atoms
dislodged from target - accelerated to substrate (10 eV
- 40 eV)
Reactive
coating (i.e. nitrogen gas - Nitrides)
Coating
build up (1.5 µm - 6.0 µm / Hr)
Substrate
temperature (400o F - 900o F).
-
How is surface finish of the object
affected?
The
PVD process usually duplicates the original finish. That
is if a 0.1 µm Ra. is present before coating, a
0.1 µm Ra. will
remain after coating. If required additionally the finish
can later be polished to a fine mirror surface.
-
What type of material can be PVD coated?
PVD
is a low temperature process so a range of materials can
be coated for example all type of steels, brass, titanium,
aluminum etc. Even ABS plastic can be coated.
-
How hard are coatings?
At ambient temperature:
TiN is 2700
- 3100 Vickers.
TiAlN is 2200
- 3000 Vickers.
TiCN is 3600
- 4400 Vickers.
AlTiN is 4000
- 5000 Vickers.
At operating temperatures, TiCN typically gets softer
and TiAlN or AlTiN gets harder.
|
|
|
