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Thin Film basics for extended product life
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|
Sulzer Metco Diamond-Like Coatings for Plastic
Molding
6000 North Bailey Avenue Suite 9 Amherst, NY 14226 Phone: 716-270-2228 Fax: 716-270-2230
Sulzer Metco
| slide 1
DLC vs Other Surface Treatments
Dylyn®/DLC Dylyn®
Cavidur® B4C Chrome Nickel Teflon WCC
DLN N * * * *
NAME
DIAMOND
LIKE
COATING
DIAMOND LIKE
NANOCOMPOSITE
COATING
TITANIUM
NITRIDE
Diamond
Black
Electroplated
CHROME
Electroless
Nickel
Teflon®
Composite
Tungsten
Carbide
Carbon
MICROHARDNESS
(GPa)25 18 30 23 35 8 - 12 4 - 8 10 - 12
ROCKWELL C 85 78 90 80 95 64 - 70 40 - 60 66 - 70
COEFFICIENT OF
FRICTION AGAINST
STEEL (DRY)
0.12 0.07 0.1 0.4 - 0.5 0.4 - 0.5 0.2 - 0.4 0.1 - 0.3 0.2 - 0.3
COATING
THICKNESS (µM)1 - 4 1 - 4 2 - 4 1 - 4 1 - 4 Up to 50 5 - 50 2 - 4
570 °F 750 °F 840 °F 1000 °F 1800 °F 600 °F 750 °F 570 °F
300 °C 400 °C 450 °C 600 °C 980 °C 325 °C 400 °C 300 °C
350 - 430 °F 350 - 430 °F 480 - 660 °F 500 - 950 °F 500 - 950 °F 120 - 175 °F 120 - 175 °F 440 - 480 °F
180 - 220 °C 180 - 220 °C 250 - 350 °C 260 - 500 °C 260 - 500 °C 50 - 80 °C 50 - 80 °C 225 - 250 °C
1 - 5 5 - 10 1 - 5 250 41
+++ +++ +++ ++ ++ + + ++
SURFACE ENERGY
(mN/m)40 - 50 20 - 40 40 - 50 40 - 42 20 - 30 46 - 53
COATING METHOD PACVD PACVDPVD /
PACVDPVD PVD
Galvanic
Plating
Electroless
PlatingPVD
Properties of Other Surface Properties of DLC CoatingsTiN
COATING
TEMPERATURE
MAX. WORKING
TEMPERATURE
COATING
MATERIAL
WEAR FACTOR
(x 10-8 mm3/Nm)
* Not a Sulzer Product listed for comparison purposes only.
Sulzer Metco
| slide 2
Traditional Methods of Surface Treatment
Dicronite® Dry Lube • deposition of 0.000020 inch (0.5 microns) “maximum”
• Not a line-of-sight process
• only corrosion hindering
• Composition - modified (WS2) Tungsten Disulfide in lamellar form.
• Hardness - 1.0 - 1.5 Moh’s scale.
• Co-efficient of Friction - 0.030 inclined plane method, against itself.
Electrolysis Nickel Teflon Composite • Excellent Lubricity (20 - 25% Teflon in deposit)
• Excellent release properties
• Lowest coefficient of friction
• Hardness: 62 Rc
• Weak adhesion to the surface
Chrome Plating • Finishing necessary on wear parts to eliminate chrome
nodules.
• For optimized frictional and lubricating properties surface
finish must be taken below 15 micro inches Rp
• Hardness: 68 Rc
• Edge build up a problem
400 X
Sulzer Metco
| slide 3
DLC Coatings
Hard amorphous carbon thin film
very hard
electrically insulating
wear resistant
Comprises C, H
Carbon in sp3 bonding => "Diamond-like" properties
There are a few variants of DLC coatings
Engineered interface layer for low film stress
a-C:H
DLC
a- C:H; a- Si:O
Hard amorphous carbon thin film
very hard
electrically insulating
wear resistant
lower friction
low film stress
Comprises C, H, Si, O
a-C:H ~ "Diamond-like" properties
a-Si:O ~ enhances high temperature stability
Dylyn® is a family of coatings
Low intrinsic stress
This is a Sulzer exclusive coating - Several US patents issued
Dylyn®
Sulzer Metco
| slide 4
ABRASION:
The high hardness of Diamond-Like Coatings reduce the likelihood of hard particle penetration into the tool or part.
Coatings Reduce Abrasive Wear
TOOL
PART
Hardness Comparison Hard Particle Soft
DLC Hard
8000
DLC Dylyn®
TiN CrN 52100
4000
5000
6000
7000
Vic
ke
rs (
HV
)
2000
0
Metal Carbon
1000
Hard Chrome
Nickel TeflonDiamond
Cavidur® N
3000
Sulzer Metco
| slide 5
Coatings Reduce Friction / Material Pickup
RESISTANCE TO ADHESION:
The chemically inert characteristics of diamond-like coatings dramatically reduce possibility of cold welding and material pickup on the surface of the tool
TOOL
PART
τ1
τ2
F=τ x A
τ1 > τ2
0.8
PTFE DLC TiN 52100
Dylyn®
CrN
0
Cavidur® N
Diamond Metal Carbon
Hard Chrome
0.1
Nickel Teflon
Co
eff
icie
nt
of
Fri
cti
on
0.7
0.6
0.5
0.4
0.3
0.2
Sulzer Metco
| slide 6
Surface Engery & Wetting Behavior of Different Coatings
lubricant fluid drop
with constant volume,
here water
wetting angle
of contact
fluid spreads
over the surface
TiAlN
TiN
Metal
Carbide DLC
Dylyn®
Better Wetting Behavior
Better Release Behavior
Close-up of a series of
liquid droplets on a
Dylyn® sample
•Surface energy is a
measure of the
affinity of a
substance to stick to
the material.
•The lower the value,
the less likely a
material will weld or
stick to a surface.
•PFTE has a surface
energy of 18 mN/m 20 - 40 40 - 42 42 - 46 46 - 53
Surface Energy (mN/m)
Sulzer Metco
| slide 7
DLC
TOOL PART
Corrosive Attack
Corrosion Test
Dylyn®
ASTM B 117-97 Salt Spray Test
The high density and
amorphous structure of
Diamond-Like Coatings
inhibit the corrosive by-
products from
penetrating into the
tool. TiN
Sulzer Metco
| slide 8
Plasma Assisted Chemical Vapor Deposition Process
Equipment designed & constructed by Sulzer Metco
Plasma Assisted Chemical Vapor Deposition (PACVD)
process
In-situ substrate cleaning via plasma etching
Substrate temperature does not exceed 220°C
Maximum part dimensions must fit within a 32” diagonal,
be less than 12” in height and weigh less than 100Kg
Sulzer Deposition System
Vacuum Pump
Reactive Plasma
Plasma Generator
Gas Supply such as CH4
Substrates
Sulzer Metco
| slide 9
Coating Penetration in Close Spaces
PACVD coating process is non-line of sight
Shadowing occurs in holes or thin slots
During the process there is a relative gas ion density.
As the gas ions travels into the restricted pathway; the charged part walls attracts the oppositely charged gas ions forming the coating.
As the gas ions go deeper into the restricted pathway, there are less available until no coating is formed.
This reduction of coating is called Shadowing and the coating forms only as deep as the width of the opening of the restricted pathway.
+
(-)
X
X
Taper
DLC Coating
+
+
+
+
+
+ + + +
+ +
+
+
+ +
+ +
+
+ + +
+ + + + + + + +
+
+ + +
+
+
+ + +
+
+ +
+ + + +
+ +
+ + + + + + +
+ +
+ +
+
+
Sulzer Metco
| slide 10
Sulzer uses an Reactive Ion Etching process to decoat diamond-like and other carbon based coating types
Stripped finish on 8620 steel typically changes about 1 to 2 Ra
This process can be used on titanium, beryllium copper and aluminum parts in addition to steels and ceramics
Stripped Masked Steel Sample
Sulzer Stripping Process
2 Ra As Coated
3 Ra
2.5 Ra
Stripped
Near Edge
Away from edge
Note: Chrome plated parts and small geometries may not be advisable to strip.
Sulzer Metco
| slide 11
Standard Coating
Multi-Layer Coating
Ti or Dylyn® Adhesion Layer
Dylyn®, Me-Dylyn® or DLC
Substrate
Substrate
Dylyn®, Me-Dylyn® or DLC
Dylyn®, Me-Dylyn® or DLC
Ti or Dylyn® Adhesion Layer
Ti or Dylyn® Adhesion Layer
Characteristics
All DLC coating have an adhesion layer
Adhesion layer influences important coating properties
Amount of hydrogen controls the hardness
Multi-layer structures
DLN interlayer acts as buffer layer, reducing stress.
Allows for thicker total coating
Thicker coating Longer wear life
Multilayer coatings resist Hertzian stresses due to their higher modulus of elasticity
Single Layer Mulit-layer
Stress Fracture
Diamond-Like Carbon Coatings (DLC)
Sulzer Metco
| slide 12
Matching the Coating & Applications / Cavidur®
Benefits of Multiple Layers
• Better Adhesion
• High Fracture Toughness
• Higher Modulus
2 to
5 µm
1 to 3 µm
1 to 2 µm
Adhesion Zone
DLC Zone
Base Material
Sorevi Coatings (Cavidur®)
Sulzer Metco
| slide 13
Comparison of sulzer vs Competitive DLC Coatings
Sulzer Dylyn®/DLC Competitive DLC
AFM – Topography (Z: 300nm/div)
Sulzer Metco
| slide 14
SEM-Comparison
Amorphous coating structure
without change in surface finish
2.5
µm
Dylyn®/DLC (PACVD) TiAlN (PVD)
5,000 X 1,000 X
Sulzer Metco
| slide 15
0.00E+00
2.00E-06
4.00E-06
6.00E-06
8.00E-06
1.00E-05
1.20E-05
1.40E-05
We
ar
(mm
3/N
m)
TiN Cr Dylyn®/DLC
Coating Wear Wear on Steel Ball (52100)
Comparison of Wear
Wear Factor
(x 10-8
mm3/Nm)
DLC 1 - 5
Dylyn®
5 - 10
WC/C 41
TiCN 60
TiN 250
TiAlN 790 - 1000
Coating
F
v Force (F): 20 N
Velocity (V): 200 RPM
Sliding Distance: 10,000
Revolutions
Sulzer Metco
| slide 16
Dry Running Properties of Materials
AISI 52100 (DIN 1.3505) uncoated
AISI 4140 (DIN 1.7225) nitrided
Cu Sn Pb - bronze AISI 52100 + BALINIT® C (WC/C)
Co
eff
icie
nt
of
fric
tio
n
Wear tracks of materials after dry running
Test time [min] 0 10 20 0
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
WC/C-PVD BALINIT C
Cold Welding
Scratches
Nearly No Wear
Dylyn®
DLC
AISI 52100 (DIN 1.3505) bearing steel, uncoated
AISI 4140 (DIN 1.7225) alloy steel, nitrided
Hard chrome plating
Electroless nickel
AISI 4135 (DIN 1.7707) alloy steel, oxynitrocarburised
Nickel-Teflon
CuSnPb-bronze
DLC Dylyn®
Sulzer Metco
| slide 17
Dylyn®/DLC is able to offer a wide variety of
properties with only ONE coating:
• lowest available coefficient of friction…
Summary
• …which is maintained by the high hardness
• no surface roughness changes … that could
influence galling and release properties • 100% corrosion protection
• Coating temperature below 200°C
• Removable!!
• Biocompatible
Sulzer Metco
| slide 18
General Application Guidelines for Diamond-Like Coating
For molding surfaces: Use the Dylyn® family of
coatings
For sliding surfaces: Use the DLC family of
coatings
Both coatings can work for molding or sliding
applications, but we typically look at the primary
need to determine which coating is the primary
choice
There are multiple recipes available and if the
first coating recipe did not fully satisfy; we can
determine by analyzing the results what the
optimum coating recipe should be
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