|
|
A revolution in wear resistance technology
for the plastic and rubber molding industries! |
Reduce Downtime by 50%!
Reduce Rebuild Costs by 30%!
Improve Production Efficiency!
|
 |
| The
Concept |
| Surface Engineering's Extreme Coatings™ process utilizes emerging
Thermal Spray technologies to apply extremely wear resistant coatings to virtually any
size injection molding or extrusion screw. This process provides crack free coatings with
hardness values ranging from 55-75 on the Rockwell "C" scale in thickness from
0.003"-0.050". Proprietary compositions of various Carbides, Ceramics, and
Alloys are incorporated to achieve abrasion resistant characteristics unmatched by any of
the conventional hardfacing alloys popular today! This process completely eliminates the
necessity for Chrome Plating, Flame Hardening, or Nitriding, as the entire screw surface
is coated, including the root and flite sides. The coatings are much more wear resistant
than any of the three aforementioned processes, which makes the process excellent for
screws exposed to fiber filled compounds. Furthermore, the process requires no preheat of
postheat procedure, and during application, components rarely exceed temperatures of
350°F. The low heat input helps prevent distortion, minimizing costly straightening
and/or machining time. It also allows for the repair of D-2 Tool Steel components,
typically scrapped when completely worn. Preparation for screw rebuilding requires only
touch up work and the removal of old Chrome before the coating application. Another unique
aspect of the process is the "Dualcoat" concept. This targets those who require
extreme wear resistance through the root of a screw, but whose barrels may not be
compatible with the hardness of the root coating. In this case, the flights may be coated
with a more traditional product, but will be masked during application of the harder root
coating, thus eliminating compatibility issues and maximizing screw life. It also must be
noted that today’s popular hardfacing alloys can be applied via the Extreme Coatings
process with an improvement in screw life. This is due to the elimination of base metal
dilution inherent to welded overlays. Other applications where this process is currently
utilized includes Turbine Components, Bushings, Shafting, Mixer Blades, Chutes, Fan
Blades, Conveyors, Slurry Pumps, and many other applications where extreme conditions of
wear exist. |
 |
| - |
| The
Process |
| As the gas mixture burns, the powder particles are melted and
accelerated down the barrel. Temperatures above 6000 ºF are attained with the combustion
chamber while the substrate temperature is maintained below 350 ºF by a gas cooling
system. Particle velocities of approximately 2,500 ft/s are produced. The kinetic energy
released by impingement upon the substrate contributes additional heat and promotes
bonding, high density, and appreciable hardness values. The coating is built up to the
specified thickness while the workpiece is rotated or passed in front of the gun. |
|
| - |
| Component
Preparation |
Surface Preparation is the most critical step in a thermal spraying
operation. Coating adhesion quality is directly related to the cleanliness and roughness
of the substrate surface. The coating material and the substrate type are the major
factors in determining what surface preparation is necessary to achieve consistent
bonding. Sprayed deposits do not add to the strength of the substrate. The purposes of
surface roughening are as follows:
- provide compressive surface stresses
- provide interlocking laminations (layers)
- increase the bond area
- decontamination of the surface
Internal stresses from shrinkage develop in coatings and these stresses
increase with increased coating thickness. The stresses are more severe in hard metals or
ceramics. Roughening is a method of reducing these stresses by dividing the internal
stresses into smaller components which will cancel each other out. As the layers are
folded up and down, the coating strength is improved. |
|
| - |
| Wear
Mode |
| Surfaces subjected to low stress abrasion show that material has been
removed by hard, sharp particles or other hard, sharp surfaces plowing material out in the
furrows. Grinding with a surface grinder can be a controlled from of low stress abrasion.
The low stress qualifier means that the abradant is imposed on the surface with relatively
low normal forces. The operating forces must be low enough to prevent crushing the
abradant. Low stress abrasion rates are directly proportional to the sliding distance and
the load on the particles or protuberances and are significantly reduced by hard
microconstituents within the surface microstructure. |
|
| - |
| Abrasion
Resistance Data |
| Coating/Alloy |
Chemical
Composition |
Application
Process |
Average
Hardness |
Volume
Loss mm³ |
| DPH 300g |
Est.Rc |
| XC1000 |
88% Wc 12% Co |
HVOF |
1100 |
68-71 |
3.0 |
| XC1000 |
83% Wc 17% Co |
HVOF |
1000 |
67-70 |
4.7 |
| XC4000 |
75% Cr2C3 25% NiCr |
HVOF |
650 |
62-64 |
3.2 |
| XC6000 |
50% NiCrB 50% Wc |
HVOF |
750 |
64 |
5.9 |
| XC7000 |
Nickel-Cr-Boron |
HVOF |
|
60 |
11 |
| XC8000 |
Co-Cr-W |
HVOF |
|
57 |
18 |
| Stellite 6 |
Co-Cr-W |
TIG |
|
Actual 40 |
64 |
| Stellite 12 |
Co-Cr-W |
TIG |
|
Actual 47 |
57 |
| Stellite 1 |
Co-Cr-W |
TIG |
|
Actual 54 |
52 |
| 56 |
Nickel-Cr-Boron |
TIG |
|
Actual 49 |
15 |
| D2 |
Tool Steel |
WROUGHT |
|
60 |
12 |
| 316 |
Stainless Steel |
TIG |
|
N/A |
83 |
| "C" |
Nickel-Cr-Mo |
TIG |
|
16 |
105 |
|
|
| - |
| The
Coatings |
| Type |
Rc |
Descriptions |
| XC1000 |
68-70 |
A composition of Cobalt saturated with 80-90% Sub-Micron sized Tungsten Carbide
with a particulate hardness average of Rc 82, providing ultimate abrasion resistance. |
| XC2000 |
70-74 |
An Oxide of Chromium combined with an Oxide of Silicon
providing extreme abrasion resistance and hardness. |
| XC3000 |
65 |
An Oxide of Aluminum producing very hard, dense, and smooth coatings. Resists
very fine particulate abrasion. Corrosion resistant. |
| XC4000 |
55-65 |
A composition of Nickel, Chromium, and Chromium Carbide
producing an abrasion resistant. Coating with extreme corrosion resistance and excellent
ductility, relative to hardness. |
| XC5000 |
60 |
A proprietary composition of Molybdenum and Tungsten Carbide producing unique
antigalling and abrasion resistance. |
| XC6000 |
55-60 |
A Nickel-Chrome-Boron alloy system combined with 50-60%
Tungsten Carbide providing extreme abrasion and corrosion resistance. |
| XC7000 |
60 |
A Nickel-Chrome-Boron alloy system similar to "56" only much more
abrasion resistant. |
| XC8000 |
58 |
A Cobalt base alloy system similar to Stellite 12™, only
much more abrasion resistant. |
| XC-RD |
75-80 |
Tungsten Carbide / Cobalt; A Unique sub-micron manufacturing process providing
improved wear resistance over the traditional Wc/Co coating. |
|
|
 
|
|
