Method for thinning specimen
View Patent ↗A method for thinning (such as in grinding and polishing) a material surface using an instrument means for moving an article with a discontinuous surface with an abrasive material dispersed between the material surface and the discontinuous surface where the discontinuous surface of the moving article provides an efficient means for maintaining contact of the abrasive with the material surface. When used to dimple specimens for microscopy analysis, a wheel with a surface that has been modified to produce a uniform or random discontinuous surface significantly improves the speed of the dimpling process without loss of quality of finish.
1. A method for thinning a surface of a specimen, comprising:
mounting a specimen with an exposed surface on a platform,
moving a thinning member article having a discontinuous surface relative said exposed surface using an instrument means, said thinning member article has a discontinuous surface with greater than 10 discontinuities representing greater than approximately 5% of the area of the surface of the thinning member article, said discontinuities selected from the group consisting of grooves, slots, voids, depressions and holes; and
dispersing an abrasive material to achieve contact of the abrasive material with the discontinuous surface and the exposed surface, thereby thinning the exposed surface of the specimen.
2. The method of claim 1 wherein said thinning member article comprises a material selected from stainless steel, bronze, brass, copper, a ceramic material, fiberglass, a phenolic composite material, wood, a fiber material, a polymeric material, and a plastic material.
3. The method of claim 1 wherein said thinning member article has a surface with patterned discontinuities.
4. The method of claim 1 wherein said thinning member article has a surface with random discontinuities.
5. The method of claim 1 wherein said thinning member article has a geometry selected from a cylinder, a sphere, and a polyhedra.
6. The method of claim 5 wherein said thinning member article is a wheel.
7. The method of claim 1 wherein said abrasive material comprises a material selected from diamond, alumina, boron-carbide, cubic boron-nitride, and silicon-carbide.
8. The method of claim 7 wherein said abrasive material comprises particles less than approximately 30 microns in diameter.
9. The method of claim 1 wherein said thinning member article has a surface with grooves spaced at approximately 10° intervals around said surface.
10. The method of claim 9 wherein said thinning member article has a surface with grooves cut at an orientation selected from perpendicular to the surface and beveled with respect to the surface.
11. The method of claim 1 wherein the specimen is rotated.
12. The method of claim 1 wherein said thinning member article has a surface modified by sanding the surface.
13. The method of claim 1 wherein said thinning member article comprises a porous bronze material produced by sintering bronze particles together into a solid with high porosity.
14. The method of claim 1 wherein said thinning member article is a wheel rotated at less than approximately 100 revolutions per minute.
15. The method of claim 1 wherein said instrument means applies a force of less than approximately 60 grams to the exposed surface.