Super abrasive grinding wheels

• US 5,658,194 A
• Filed: 01/23/1996
• Issued: 08/19/1997
• Est. Priority Date: 04/12/1994
• Status: Expired due to Term

• Current Assignee: Norton Healthcare Incorporated
• Original Assignee: Norton Healthcare Incorporated
• Inventors: Micheletti, Patrick
• Primary Examiner(s): Smith, James G.
• Assistant Examiner(s): EDWARDS, DONA
• Application Number:
  US08/549,819
• Time in Patent Office: 574 Days
• Field of Search: 451/540, 451/451, 51/309, 51/293, 51/295
• US Class Current: 451/541
• CPC Class Codes: B22F 2998/00 Supplementary information concerning processes or compositions relating to powder metallurgy
• CPC Class Codes: B22F 3/1112 comprising hollow spheres or hollow fibres
• CPC Class Codes: B24B 9/10 of plate glass
• CPC Class Codes: B24D 3/06 metallic or mixture of metals with ceramic materials, e.g. hard metals, "cermets", cements
• CPC Class Codes: B24D 3/10 for porous or cellular structure, e.g. for use with diamonds as abrasives
• CPC Class Codes: B24D 3/34 characterised by additives enhancing special physical properties, e.g. wear resistance, electric conductivity, self-cleaning properties
• CPC Class Codes: C22C 26/00 Alloys containing diamond or cubic or wurtzitic boron nitride, fullerenes or carbon nanotubes

Abstract

The invention relates to a superabrasive grinding wheel comprising very hard abrasive particles and a binder with a metallic matrix, which also contains "pore-forming" adjuvants, notably hollow beads made of ceramic.

This grinding wheel may be used notably for the machining or grinding of glass articles, especially for the grinding of the edges of glass sheets.

Claims

1. Superabrasive grinding wheel comprising very hard abrasive particles of diamond or cubic boron nitride and a binder with a metallic matrix and pore-forming elements, wherein the pore-forming elements are hollow beads of ceramic, the walls of which have a thickness of between 2 and 8 micrometers, whereby breakage of the walls of the hollow beads and waste removal is facilitated.

2. Grinding wheel according to claim 1, wherein the hollow beads have an outer diameter of between 1 micron and 3 mm.

3. Grinding wheel according to claim 2, wherein the hollow beads have an outer diameter between 100 microns and 1 mm.

4. Grinding wheel according to claim 1, wherein the pore-forming elements are added in a proportion of a volume of 1 to 80% of the total volume of the grinding wheel.

5. Grinding wheel according to claim 4, wherein the pore-forming elements are added in a proportion of a volume of between 5 and 50% of the total volume of the grinding wheel.

6. Grinding wheel according to claim 5, wherein the pore-forming elements are added in a proportion of a volume of approximately 30% of the total volume of the grinding wheel.

7. Grinding wheel according to claim 1, wherein the metallic matrix of the binder is selected from the group consisting of bronze, silver, cobalt, iron, copper and mixtures thereof.

8. Grinding wheel according to claim 1, wherein the binder with metal matrix contains a tungsten carbide additive.

9. Grinding wheel according to claim 1, wherein the abrasive particles correspond to 5 to 60% of the total volume of the grinding wheel.

10. Grinding wheel according to claim 9, wherein the abrasive particles correspond to 10 to 30% of the total volume of the grinding wheel.

11. Grinding wheel according to claim 1, wherein the abrasive particles are rounded in shape or needle-shaped, with a grain size of between 4 and 1182 in FEPA standardized coding.

12. Grinding wheel according to claim 11, wherein the abrasive particles are rounded in shape or needle-shaped, with a grain size of approximately 40 to 90 in FEPA standardized coding.

13. Grinding wheel according to claim 1, wherein said hollow ceramic beads are made of alumina or mullite.

14. Grinding wheel according to claim 1, wherein the hollow beads have a wall thickness between 4 and 6 micrometers.

15. A method of grinding glass articles, comprising grinding a glass article with the grinding wheel of claim 1.

16. The method of claim 15, comprising grinding an edge of a glass sheet.