CATHODIC ARC P.V.D. FAQ

How is the surface finish effected?
Our process may add 1 - 2 micro-inches of roughness. Post coat polishing is possible.

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 ID's be coated?
Yes, but there are some depth limitations for PVD coatings.

Does the coating process change part dimensions?
Yes. Change depends on the coating, its specified thickness and the coating process. Typically PVD is recommended for high tolerance parts. Most PVD coatings add 2-3 microns per side to a component. PVD CrN coatings are thicker and can add 10 microns or more in some cases. Processing temperatures may grow or shrink some substrate materials.

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?
400 ¡ F - 900 ¡ F controlled by part temperature for PVD.

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 get harder.


What are the typical performance test requirements?
BHMA Test (Ref. ANSI/BHMA A156.18-1993 Test Procedures)
Procedure Required Required
with TiN		 Test
Salt Spray
Humidity
Pencil Hardness
Perspiration
UV Resistance
Tabor Abrasion
MEK Rubs
Scratch Resistance
Color		 96 Hrs
240 Hrs
4H
4 Cycles
144 Hrs
500 Cycles		 1000 Hrs
1000 Hrs
6H
4 Cycles
500 Hrs
1000 Cycles
4H
CIE Lab		 ASTM B 117-90
ASTM D 3359-78
BHMA A156.18
BHMA A156.18
ASTM G 53-91
ASTM D 4060
ASTM D 4752
ASTM D 3363
BHMA (Builders Hardware Manufacturers Association)

What are the typical process steps in applying a coating?
Ultrasonic pre-cleaning of the components.

  • Vacuum (10-5 Torr - 10-7 Torr)
  • Glow Discharge (Reverse Plasma Etch)
  • High Negative Potential (between parts/anode and evaporation/cathode source) 20 Volts - 40 Amps
  • Argon gas is ionized via an electric discharge (plasma)
  • Positive argon ions are accelerated to target (100 eV - 1000 eV)
  • Atoms dislodged from target - accelerated to substrate (10 eV - 40 eV)
  • Reactive sputtering (nitrogen gas - Nitrides)
  • Coating build up (1.5 mm - 6.0 mm / Hr)
  • Substrate temperature (200o - 500o C)