Apparatus and method for outer surface enhancement and compaction of a cylindrical structure using glass failure generated pulse

• US 10,639,696 B1
• Filed: 09/29/2017
• Issued: 05/05/2020
• Est. Priority Date: 09/29/2017
• Status: Active Grant

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Dudt, Philip, Barsoum, Roshdy George
• Primary Examiner(s): Eiseman, Adam J
• Assistant Examiner(s): London, Stephen Floyd
• Application Number:
  US15/719,868
• Time in Patent Office: 949 Days
• Field of Search: 72 53, 72 56, 72 61, 72 62
• CPC Class Codes: B21D 26/08 generated by explosives, e.g. chemical explosives
• CPC Class Codes: B23P 9/00 Treating or finishing surfaces mechanically, with or without calibrating, primarily to resist wear or impact, e.g. smoothing or roughening turbine blades or bearings treatment covered by a single other subclass, see the relevant subclass, e.g. B24C, C21D7/00, C22F1/00; Features of such surfaces not otherwise provided for, their treatment being unspecified
• CPC Class Codes: C21D 1/06 Surface hardening
• CPC Class Codes: C21D 10/00 Modifying the physical properties by methods other than heat treatment or deformation
• CPC Class Codes: C21D 7/04 of the surface

Abstract

An apparatus and method for treatment of articles, using glass failure generated pulses. The apparatus and method is directed towards the hardening and compaction of an elongated cylindrical article surrounded by a glass sleeve in a confined arrangement. The apparatus includes a striker for striking the glass sleeve to create an explosive reaction that pressure-treats the cylindrical article, thereby causing the hardening and compaction.

Claims

1. A system for hardening and compacting a cylindrical structure, the system comprising:

a confinement assembly comprising;

a cylindrical structure having a longitudinal axis;

a glass sleeve surrounding and contacting the cylindrical structure; and

a rigid outer shell encasing the glass sleeve and the cylindrical structure therewithin;

a striker assembly comprising;

a flat backing portion; and

a protrusion portion extending from the flat backing portion;

a launching mechanism for launching and directing the striker assembly in a direction substantially parallel to the longitudinal axis, to shatter the glass of the glass sleeve to create an explosive volume expansion of the glass, which due to the confinement assembly results in compressive forces being applied to the surface of the cylindrical structure, thereby hardening and compacting the cylindrical structure.

2. The system for surface hardening and compacting a cylindrical structure of claim 1, wherein the launching mechanism comprises one of a projectile component, or an explosive charge for launching and directing the striker assembly towards the confinement assembly at velocities between 500 feet per second to 20,000 feet per second, so that upon impact, one or more of the following occurs:

a. multiple cracks form in the glass sleeve so that the volume occupied by glass in the glass sleeve increases as the cracks rupture and expand;

b. failure waves propagate through the glass sleeve with kinetic energy stored ahead of the waves;

c. the glass sleeve develops at least one of coesite, stishovite, or seifertite which rupture and convert to an amorphous state through a volume change;

so that the occurrences of one or more of a, b, or c, creates said explosive volume expansion of the glass, which results in said compressive forces being applied to the surface of the cylindrical structure.

3. The system for surface hardening and compacting a cylindrical structure of claim 2, wherein the protrusion portion has a triangular profile with a pointed tip for impacting the glass sleeve.

4. The system for surface hardening and compacting a cylindrical structure of claim 2, wherein the protrusion portion has a stepped profile with two or more steps for impacting the glass sleeve.

5. The system for surface hardening and compacting a cylindrical structure of claim 3, wherein the cylindrical structure is a shaft.

6. The system for surface hardening and compacting a cylindrical structure of claim 4, wherein the cylindrical structure is a shaft.

7. The system for surface hardening and compacting a cylindrical structure of claim 2, wherein the cylindrical structure comprises a cylindrical membrane or foil filled with powdered or granular ceramic materials.

8. The system for surface hardening and compacting a cylindrical structure of claim 7, wherein the protrusion portion has a rectangular profile with a flat head for impacting the glass sleeve.

9. A method of hardening and compacting a cylindrical structure, the method comprising:

providing a confinement assembly comprising;

a cylindrical structure having a longitudinal axis;

a glass sleeve surrounding and contacting the cylindrical structure; and

a rigid outer shell encasing the glass sleeve and the cylindrical structure therewithin;

providing a striker assembly comprising;

a flat backing portion; and

a protrusion portion extending from the flat backing portion;

directing the striker assembly towards the confinement assembly in a direction substantially parallel to the longitudinal axis, so that the protrusion portion strikes the glass sleeve, to shatter the glass of the glass sleeve, thereby creating an explosive expansion of the glass, wherein due to the limited space within the confinement assembly, compressive forces are created and applied to the surface of the cylindrical structure, thereby accomplishing said hardening and compacting of the cylindrical structure.

10. The method of surface hardening and compacting of claim 9, wherein in the directing of the striker assembly towards the confinement assembly, the striker assembly is directed towards the confinement assembly at velocities between 500 feet per second to 20,000 feet per second, so that upon impact, one or more of the following occurs:

a. multiple cracks form in the glass sleeve so that the volume occupied by glass in the glass sleeve increases as the cracks rupture and expand;

b. failure waves propagate through the glass sleeve with kinetic energy stored ahead of the waves;

c. the glass sleeve develops at least one of coesite, stishovite, or seifertite which rupture and convert to an amorphous state through a volume change;

so that the occurrences of one or more of a, b, or c, creates said explosive volume expansion of the glass, which results in said compressive forces being applied to the surface of the cylindrical structure.

11. The method of surface hardening and compacting of claim 10, wherein in the providing of the striker assembly, the protrusion portion is provided with one of, a triangular profile with a pointed tip for impacting the glass sleeve, or a stepped profile with two or more steps for impacting the glass sleeve.

12. The method of surface hardening and compacting of claim 11, wherein in the providing of the confinement assembly, the cylindrical structure is a shaft.

13. The method of surface hardening and compacting of claim 10, wherein in the providing of the confinement assembly, the cylindrical structure is a cylindrical membrane or foil filled with powdered or granular ceramic materials.

14. The method of surface hardening and compacting of claim 13, wherein in the providing of the striker assembly, the protrusion portion has a rectangular profile with a flat head for impacting the glass sleeve.