LASER AUGMENTED DIAMOND DRILLING APPARATUS AND METHOD

• US 20170120345A1
• Filed: 10/28/2016
• Published: 05/04/2017
• Est. Priority Date: 10/30/2015
• Status: Active Grant

• Current Assignee: The Board of Trustees of Western Michigan University
• Original Assignee: Western Michigan University
• Inventors: Patten, John A., Mohammadi, Hossein
• Granted Patent: US 10,183,337 B2
• Time in Patent Office: Days
• CPC Class Codes: B23B 2226/18 Ceramic
• CPC Class Codes: B23B 2226/27 Composites
• CPC Class Codes: B23B 2226/31 Diamond
• CPC Class Codes: B23B 2226/315 polycrystalline [PCD]
• CPC Class Codes: B23B 2250/12 Cooling and lubrication
• CPC Class Codes: B23B 2251/14 Configuration of the cutting part, i.e. the main cutting edges
• CPC Class Codes: B23B 2251/18 Configuration of the drill point
• CPC Class Codes: B23B 2251/50 Drilling tools comprising cutting inserts
• CPC Class Codes: B23B 2260/092 Lasers
• CPC Class Codes: B23B 35/00 Methods for boring or drilling, or for working essentially requiring the use of boring or drilling machines; Use of auxiliary equipment in connection with such methods
• CPC Class Codes: B23B 41/00 Boring or drilling machines or devices specially adapted for particular work surgical drilling machines A61B17/16; Accessories specially adapted therefor
• CPC Class Codes: B23B 51/08 Drills combined with tool parts or tools for performing additional working B23G5/20 takes precedence
• CPC Class Codes: B23K 2101/20 Tools
• CPC Class Codes: B23K 2103/50 Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26
• CPC Class Codes: B23K 26/0093 combined with mechanical machining or metal-working covered by other subclasses than B23K combined welding or cutting procedures or apparatus B23K28/02
• CPC Class Codes: B23K 26/0622 by shaping pulses
• CPC Class Codes: B23K 26/0823 Devices involving rotation of the workpiece
• CPC Class Codes: B23P 25/006 Heating the workpiece by laser during machining
• CPC Class Codes: Y10S 408/701 Cutting by use of radiant energy, e.g. laser, maser

Abstract

A laser beam is transmitted through a drill bit comprising diamond or other suitable light-transmitting material having sufficient hardness. The laser beam exits a tip of the drill bit, thereby heating and softening the material being drilled at and/or near the interface of the drill with the material being drilled. The process may be utilized to drill hard and brittle materials such as ceramics and semiconductors, composites and ceramic matrix composites. The process may cause high pressure phase transformation, resulting in a more ductile and plastic material near the drill point/tip. The process provides more rapid drilling, improved surface quality in drilled holes, and less tool wear.

Claims

1. A method of machining a hard and/or brittle material, the method comprising:

directing a laser beam through at least a portion of a light-transmitting cutting tool having at least one cutting edge whereby the laser beam exits the cutting tool adjacent the cutting edge;

bringing the cutting edge into moving contact with a surface of a hard and/or brittle material whereby the laser beam heats the surface and softens the material adjacent the surface.

2. The method of claim 1, wherein:

the cutting tool has first and second opposite ends, and wherein the cutting edge is disposed on the first end, and the laser beam enters the second end of the cutting tool.

3. The method of claim 1, wherein:

the light-transmitting material comprises a single crystal diamond.

4. The method of claim 2, wherein:

the light-transmitting material comprises a poly crystal diamond.

5. The method of claim 1, wherein:

the cutting tool comprises a drill bit having an elongated cutting edge; and

wherein;

the laser beam has an oblong shape in cross section that is aligned with the elongated cutting edge.

6. The method of claim 1, wherein:

the brittle material comprises a ceramic.

7. The method of claim 1, wherein:

the brittle material comprises at least one of a single crystal silicon and a composite material.

8. The method of claim 1, including:

introducing cutting fluid onto at least one of the surface of the brittle material and the cutting tool.

9. The method of claim 1, wherein:

the cutting tool comprises a drill bit having at least two elongated cutting edges and wherein;

the laser beam exits the drill bit along the at least two cutting edges.

10. A laser augmented drilling system, comprising:

a laser source;

a movable cutting tool having first and second opposite ends, the second end having at least one cutting edge, and wherein the cutting tool comprises a light-transmitting material;

wherein the laser source is configured to direct a laser beam from the laser source into the first end of the cutting tool whereby the laser beam is transmitted through the light-transmitting material and exits the second end of the cutting tool and heats a material being drilled by the movable cutting tool.

11. The laser augmented drilling system of claim 10, wherein:

the cutting tool comprises a drill bit having at least one cutting edge comprising a light-transmitting diamond material.

12. The laser augmented drilling system of claim 11, wherein:

the drill bit includes two cutting edges comprising a light-transmitting diamond material.

13. The laser augmented drilling system of claim 10, including:

an optical fiber operably interconnecting the laser source and the movable cutting tool.

14. The laser augmented drilling system of claim 10, wherein:

the laser source comprises an IR CW laser.

15. A drill bit comprising:

a metal body portion having a passageway;

a tip having at least one elongated light-transmitting cutting edge that is in optical communication with the passageway such that a laser beam can be directed through the passageway and through the tip to the at least one cutting edge.

16. The drill bit of claim 15, wherein:

the tip comprises a single crystal diamond material.

17. The drill bit of claim 15, wherein:

the tip comprises a poly crystal diamond material.

18. The drill bit of claim 15, wherein:

the tip comprises two cutting edges.

19. The method of claim 15, wherein:

the tip comprises a substantially transparent material.

20. A method of drilling a hole in a composite material, comprising:

bringing a rotating bit into contact with a composite material in a manner that produces a hole in the composite material having a surface that is substantially free of defects.