– “Random” motion processes
➢ CAVF, abrasive tumbling, drag finishing, etc.
– Can be purely abrasive (mechanical) or chemical mechanical
– Utilize “media” of some sort to impart rubbing force onto the surface of the component
– Vibratory Tubs or Bowls
– Centrifugal Disc Machines
– Drag Finishers
– Numerous potential compositions
➢ Abrasive or non-abrasive
➢ Ceramic, porcelain, plastic, metal
– Numerous potential shapes and sizes
➢ Cylinders, wedges, triangles, tristars, cones, tetrahedrones
➢ Angle cut or straight cut edges
➢ <1 mm in size or > 75 mm
– Finishing Proces
– Isotropic finish Process
➢ Creates flat surfaces
➢ For metal components
➢ Ferrous Steels (Inc. Pyrowear 53 & AISI 9310), Titanium, Inconel/Nimonic’s Nickel Alloys, Stainless Steels
Produces Surfaces Ra <0.1µm (<0.075µm)
➢ Creates unique non-directional Micro-Texture
Maintains Geometry
➢ Chemical & mechanical process
➢ Vibratory equipment
➢ High density, non-abrasive ceramic media or media mix.
➢ Two stage chemical process
– Creates the energy for the process
➢ Off Set weights generate centrifugal
inertia
➢ Generates vibration
– Acts as reaction vessel
– Composition
– Off Set weights generate centrifugal inertia
➢ Aluminium Oxide
➢ Polyester Resin
– Can comprise of mixtures
➢ Composition, size and shape
– Removes the metal.
– Vibrator causes media to roll
– Media rubs over component
– Cannot remove metal without chemical!
– Weak Acids
– Acts as a catalyst
➢ Aluminium Oxide
Increased Resistance to Contact Fatigue
~3x Lifecycle Increases – NASA Contact Fatigue Evaluation, X53 Spur Gears
Elimination of Micropitting
No Micropitting or Profile Form Deviation in FZG testing – University of Bochum
Increased Scuffing Resistance
~2x applied Scuffing Load without Scuffing – Cardiff University
Increased Power Density Allowable
~42% Increased Power Density Allowable – Pratt & Whitney Patent WO 2007/0646330
Reduced Friction
Elimination of Initial Break-In Cycle – Falex 3 Ball on Flat Testing
Increased Lubricant Performance
32 – 53° C Lubricant Temperature Reduction – Arizona Truck Technical Center, Hot Weather Testing
Reduced Wear
45% reduced Iron Content in Oil post 100,000 miles – New York City Taxi Fleet Study
Increased Resistance to Bending Fatigue
~5% Increase in Resistance to Bending Fatigue – University of Newcastle STBF Test
Ease of Implementation
Does not affect Component Geometry, Heat Treatment (including Nitriding), or Metallurgy
– Utilizes “active” chemistry
➢ Generates a self-limiting, soft conversion coating
➢ Lowersrequired force to refine the surface
– Mechanism:
➢ Conversion coating is removed by non-abrasive media
➢ Conversion coating reformsin the processing appartus
➢ Surface is gently refined
➢ Cycle Time ~2 – 4 hours
➢ Ra < 0.1 µm
– Lower roughness achievable pending processing parameters
➢ Applications:
– Gears, Turbine Blades, Bearings, and many more
➢ Automatable
➢ Batch Process, High Volume Capability
Applicable Metals
– Carbon Steels, Stainless Steels, Exotic Steels
➢Examples: SAE 9310, AMS 6308 (Pyrowear® 53), 300 & 400 seriesstainless steel, AMS 6517 (Ferrium® C61), AMS 6509 (Ferrium® C64)
– Nickel-based Superalloys & Titanium Alloys
Applicable Heat Treatments
– Through Hardening
– Case Carburization
– Nitriding
– Induction Hardening
Cycle Time ~5 – 10 minutes
Ra < 0.25 µm
– Lower roughness achievable pending processing parameters
Applications:
– Ring & Pinion, TransmissionGears, Engine Components
Fully Automatable
Low WIP, High Volume Capability
| Sample | Contact Stress (ksi) | Test Duration (million cycles) | Failure Mode |
| Ground/Honed Baseline | |||
| #1 | 400 | 3,6 | Pitted |
| #2 | 400 | 4.2 | Pitted |
| #3 | 400 | 3.5 | Pitted |
| Abral #1 | 400 | 44.0 | Pitted |
| Abral #2 | 425 | 1.0 | Plastic Flow |
| ISF #1 | 400 | 20.0 | No Failure |
| Same specimen and load roller tested at each stress level. | 425 | 20.0 | No Failure |
| sequentially | 450 | 22,4 | No Failure |
| Cumulative Result | 400-450 | 62.4 | No Failure |
| ISF #2 | 400 | 5.0* | No Failure |
| Same specimen and load roller tested at each stress level. | 425 | 5.0* | No Failure |
| sequentially | 450 | 20.0 | No Failure |
| Cumulative Result | 400-450 | 30.0 | No Failure |
Ra’s = Ground/Honed ~0.25 µm; ISF <0.04 µm; Abral <0.04 µm (mirror)
Ra’s = Ground 0.23 – 0.30 µm; ISF 0.05 – 0.076 µm
Ra’s = Ground 0.42 – 0.52 µm; ISF 0.07 – 0.13 µm
Ra’s = Ground 0.42 – 0.52 µm; ISF 0.07 – 0.13 µm
| Twin Disc Scuffing Testing | Isotropic Finished (Micro-Texture) | Isotropic Finished (Zink Chips) | As Ground | |||||
| Test | 1 | 2 | 3 | 1 | 2 | 1 | 2 | 3 |
| Scuffing Load @ Failure (N) | 4150* | 4150* | 4150* | 4150 | 3452 | 2320 | 2320 | 2320 |
| Maximum Bulk Temperature of Fast Disc (°C) | 187 | Error | 168 | 201 | 199 | 189 | 197 | 204 |
| Maximum Bulk Temperature of Slow Disc (°C) | 154 | 152 | 142 | 153 | 144 | 190 | 176 | 178 |
| Average Bulk Temperature of Discs (C) | 170 | n/a | 155 | 177 | 171.5 | 189.5 | 186.5 | 191 |
Ra’s = ISF (Micro-Texture) 0.0285 – 0.0366µm, Zinc Chips <0.1 µm, Ground 0.4 µm
*No scuffing occurred even after a 30 minute endurance cycle at maximum load
| Twin Disc Scuffing Testing | Isotropic Finished (Micro-Texture) | Isotropic Finished (Mirror-Polished) | |||
| Test | 1 | 2 | 3 | 1 | 2 |
| Scuffing Load @ Failure (N) | 4150* | 4150* | 4150* | 3450 | 3450 |
| Maximum Bulk Temperature of Fast Disc (°C) | 187 | Error | 168 | 152 | 149 |
| Maximum Bulk Temperature of Slow Disc (°C) | 154 | 152 | 142 | 125 | 124 |
| Average Bulk Temperature of Discs (C) | 170 | n/a | 155 | 138 | 136 |
Ra’s = ISF (Micro-Texture) 0.0285 – 0.0366 µm, Mirror-Polished 0.0156– 0.0193 µm
| Test Specimen | Contact Stress (ksi) | Test Duration (minutes) | Result |
| SAE 9310H | 400 | 30 | No Failure |
Ra’s = ISF <0.04 µm Specimen >30 million cycles prior to testing
– Low Oil Pressure
➢10 – 15 psig below specified minimum
– High Temperature Testing
➢15 – 20 ⁰F above specified maximum
– Both = 30 minute tests@ 550 hp & 6,000 RPM
No Scoring or Contact Fatigue
from Extreme Condition Testing
Ra’s = ISF (Micro-Texture) 0.0381 – 0.157 µm, AverageRa = 0.091 µm
– 3 gearbox designs (bearing variations) subjected to “loss-of lubricant” testing
➢ PEEK Bearing Cages
➢ Steel Bearing Cages with Heat Pipes
➢Steel Bearing Cages without Heat Pipes
– ISF Process was used on all gears
➢Publicly acknowledgedat presentation
– PEEK Bearing Cages
➢ PEEK Melted at 40 minutes of operation
➢ Some signs of scuffing/discoloration
➢ Gears showed no signs of surface damage based on MPI
– Steel Bearing Cages with Heat Pipes
➢ Test suspended at 73 minutes due to rapid temperature increases
➢ Evidence of scuffing, but overall gears in good condition
– Steel Bearing Cages without Heat Pipes
➢ Test suspended at 85 minutes due to rapid temperature increases
➢ Evidence of scuffing, but overall gears in good condition
