centrifugal isotropic micro finishing bearing surfaces
TRANSCRIPT
Developing Isotropic Micro-Finishes with Centrifugal Iso-Finishing
CONTACT: Dave Davidson | [email protected] |
SME Technical Community Advisor | https://about.me/dave.davidson
Top: Typical Surface Developed from Centrifugal Iso-Finishing. 1. Isotropic – no machining or
grinding lines.2. Neutral or negative skew
(Rsk). Asperities and peaks have been planed off, more useful load bearing surface.
Bottom: Typical Gaussian Surface. 1. Grinding or Machined
Super-Finishing operation produces positive skew with peaks and asperities predominating.
2. Low micro-inch Ra profilometer readings don’t tell the whole story. This surface is much less efficient as a bearing surface.
AFTER
BEFORE
Centrifugal Iso-Finishing Bearing Surfaces. Before and after ISO-Finish processing
Graphic by Jack Clark, Surface Analytics LLC
Electron Microscopy
CBF or Centrifugal Iso-Finishing is the only method that produced a surface with a random scratch pattern. The other methods although nominally low micro-inch surfaces still are characterized by parallel ridges and grooves that minimizes the actual amount of the surface carrying the bearing load
Graphic courtesy of Jack Clark, Surface Analytics, LLC
Centrifugal Iso-Finishing Machine
Isotropic surface, ridges and grooves are blended in
Visual Comparison
The random and non-linear character of the surface finish pattern can be seen in these comparative photos that correlates with the electron microscopy of the previous slide. The ridge and groove characteristic of the non-isotropic surfaces can be seen by the naked eye as well.
Part graphics courtesy of Jack Clark, Surface Analytics, LLC
Centrifugal Iso-Finishing Machine
Isotropic surface, ridges and groves are blended in
Before and After Comparison of Rollers. (1) Visual (2) 2-D View from electron microscopy (3) 3-D View from Optical Interferometry. Graphics courtesy of Jack Clark, Surface Analytics, LLC. Isotropic Surfaces developed with post-processing using Centrifugal Iso-Finishing Methods.
Before Centrifugal Finishing - as ground surfaces.
After Centrifugal Finishing, Isotropic surfaces with neutral to negatively skewed ground surfaces.
Other Low Micro-Inch Finishing Applications
TOP: Turbine blade foil surfaces also require low micro-inch surface values. In the electron photo micrographs shown here the surfaces were reduced to 5 micro-inch Ra surface finish values by using a multiple sequence process with Centrifugal Iso-Finishing. EquipmentBOTTOM: Electron Micro-Photographs show surface effects of a Centrifugal Iso-Finishing Process on ground steel surfaces. Note the change in the surface pattern orientation.
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