Process for manufacturing thin tin/tungsten composite elements

• US 6,569,381 B2
• Filed: 04/19/2001
• Issued: 05/27/2003
• Est. Priority Date: 05/10/2000
• Status: Expired due to Fees

• Current Assignee: Herakles
• Original Assignee: SNPE
• Inventors: Le Flocʼh, Alain, Tauzia, Jean-Michel
• Primary Examiner(s): MAI, NGOCLAN THI
• Application Number:
  US09/837,208
• Publication Number:
  US 20010053331A1
• Time in Patent Office: 768 Days
• Field of Search: 419/67
• US Class Current: 419/67
• CPC Class Codes: B22F 1/09 Mixtures of metallic powders
• CPC Class Codes: B22F 2998/10 Processes characterised by the sequence of their steps
• CPC Class Codes: B22F 3/20 by extruding
• CPC Class Codes: B22F 5/12 of wires of tubes B22F5/10
• CPC Class Codes: C22C 1/045 Alloys based on refractory metals
• CPC Class Codes: F42B 12/74 of the core or solid body
• CPC Class Codes: F42B 7/046 Pellets or shot therefor

Abstract

The subject of the invention is a particularly simple and inexpensive process for manufacturing tin/tungsten composite elements having a thickness of between 1 mm and 6 mm, such as spherical shot for hunting cartridges or fishing sinkers, from a tin/tungsten powder blend. The powder blend is extruded, in the solid state, directly into a wire whose thickness is between 1 mm and 6 mm with an extrusion rate≦80 mm/s. Next, the wire is cut into pieces which are then forged to the desired shape, especially into spheres. The subject of the invention is also the aforementioned process for obtaining the wire.

Claims

1. Process for manufacturing tin/tungsten composite elements having a thickness of between 1 mm and 6 mm from a tin/tungsten powder blend, comprising:

extruding the tin/tungsten powder blend in the solid state, directly into a wire having a thickness between 1 mm and 6 mm, wherein an extrusion rate less than or equal to 80 mm/s;

cutting the wire into wire pieces; and

forging the wire pieces into a desired shape.

2. Process according to claim 1, wherein the wire has a circular cross section with a diameter between 2 mm and 4 mm.

3. Process according to claim 1, wherein extruding the tin/tungsten powder blend is performed at a temperature of between 170°

C. and 225°

C.

4. Process according to claim 1, further comprising:

subjecting the tin/tungsten powder blend to a partial vacuum before the extruding step.

5. Process according to claim 1, wherein the extruding step is carried out at an extrusion pressure between 100 MPa and 300 MPa.

6. Process according to claim 1, wherein the extruding step is carried out with an extrusion ratio between 80 and 250.

7. Process according to claim 1, wherein the extruding step is carried out at an extrusion power between 10 W and 100 W.

8. Process according to claim 1, the tin/tungsten composite elements comprise spherical shot for hunting cartridges or fishing sinkers.

10. Process according to claim 2, the tin/tungsten composite elements comprise spherical shot for hunting cartridges or fishing sinkers.

9. Process for obtaining a tin/tungsten composite wire from a tin/tungsten powder blend, comprising:

extruding the powder blend in the solid state, directly into a wire having a thickness between 1 mm and 6 mm at an extrusion rate less than or equal to 80 mm/s.