Extrusion of high temperature formable non-ferrous metals

Patent metadata

Field	Value
Publication number	US-9468960-B2
Application number	US-201214004361-A
Country	US
Kind code	B2
Filing date	Mar 7, 2012
Priority date	Mar 10, 2011
Publication date	Oct 18, 2016
Grant date	Oct 18, 2016

Abstract

Extrusion of feed materials of a high temperature formable non-ferrous metal susceptible to embrittlement during air processing uses an extrusion system having a rotatable wheel and shoe covering part of the length of a groove around the periphery of the wheel to form an arcuate passageway, the shoe having an abutment which substantially closes a second end of the passageway and an extrusion die spaced from the abutment by a die chamber. The process includes pre-heating the feed material to not less than about 390° C. in a chamber defined by a feeder device, maintaining a protective atmosphere in the chamber of the feeder device while the feed material is heated. The pre-heated feed material then is passed to an inlet end of the passageway, and drawn along the passageway, to be forced by the abutment into the die chamber and through an extrusion orifice of the die to provide extruded product.

First claim

The invention claimed is:

1. A process for extruding feed materials of a high temperature formable non-ferrous metal that is susceptible to embrittlement during in air processing, using an apparatus including an extrusion system having a rotatable wheel and shoe which is positionable to enable a shoe to cover part of the length of a groove around the periphery of the wheel to form an arcuate passageway having a first, inlet end and a second end, the shoe having an abutment which substantially closes the second end of the passageway and an extrusion die spaced from the abutment by a die chamber, the extrusion die having a die orifice; wherein feed material for the process is selected from titanium, tantalum, niobium, and an alloy of any of titanium, tantalum and niobium and the process includes the steps of:
pre-heating the feed material to a pre-heat temperature not less than about 390° C. in a chamber defined by a feeder device,
maintaining a protective atmosphere substantially free of oxygen and nitrogen in the chamber of the feeder device while the feed material is heated in the feeder device to the pre-heat temperature,
passing the pre-heated feed material from the feeder device to the inlet end of the passageway,
drawing the pre-heated feed material along the passageway to cause the pre-heated feed material to be forced by engagement with the abutment into the die chamber and through an extrusion orifice defined by the die to provide an extruded product, and
the extruded product is passed from the die orifice and cooled.

2. The process of claim 1 , wherein the pre-heat temperature is substantially in excess of a temperature solely due to friction and shear deformation of the feed material generated by rotation of the wheel and extrusion.

3. The process of claim 1 , wherein the feed material is titanium or a titanium alloy, or alloy containing near 50 atomic percent titanium and wherein the pre-heat temperature is in a range from 760° C. to 1140° C.

4. The process of claim 1 , wherein the feed material is any one of tantalum, tantalum alloy, niobium and a niobium alloy, and wherein the pre-heat is in a range from 760° C. to 1140° C.

5. The process of claim 1 , wherein the feed material is coarse grained titanium and the pre-heat temperature is not in excess of 650° C., whereby the extruded product is ultra-fine grain product.

6. The process of claim 1 , wherein the feed material comprises unconsolidated or pelletised powder, and the pre-heat temperature is from 400° C. to 850° C.

7. The process of claim 1 , wherein the feed material is passed continuously from the feeder device to the inlet of the passageway of the extrusion system.

8. The process of claim 1 , wherein the feed material is of elongate rod form and is continuously passed through the feeder device to the inlet of the passageway of the extrusion system.

9. The process of claim 1 , wherein the feed material comprises lengths of rod form, and the lengths are passed in an end-to-end series from the feeder device to the inlet of the passageway of the extrusion system.

10. The process of claim 1 , wherein the feed material comprises uncompacted or pelletised powder which is passed from the feeder device to the groove of the wheel, adjacent to the inlet of the passageway.

11. The process of claim 1 , wherein the feed material is maintained in a protective atmosphere in passing from the feeder device to the inlet of the passageway of the extrusion system.

12. The process of claim 1 , wherein the extruded product passes from the die orifice into a protective atmosphere in which the extruded product is cooled to a temperature at which it can be exposed to atmospheric oxygen and nitrogen.

13. The process of claim 1 , wherein the protective atmosphere comprises argon.

14. The process of claim 1 , wherein the feed material comprises solid, or compact powder, rod form feed material which is pre-heated to a temperature of from about 800° C. to 1100° C. and, on start-up of extrusion, components of the extrusion system rapidly heat up to a respective initial operating temperature and are cooled to achieve respective steady state temperatures, and wherein start-up temperatures are:

CR
200-400° C.

SI
300-450° C.

A
300-600° C.

DI
300-500° C.

W
100-400° C.

where CR designates a coining roll adjacent to the inlet to the passageway, with the temperatures taken at a roll bearing housing of the extrusion system;
SI designates a shoe insert of the shoe;
A designates the abutment;
DI designates a die insert of the die; and
W designates the wheel.

15. The process of claim 14 , wherein the start-up temperatures are:

CR
250-300° C.

SI
320-400° C.

A
450-550° C.

DI
350-400° C.

W
180-300° C.

16. The process of claim 14 , wherein the steady state temperatures are:

CR
300-400° C.

SI
600-700° C.

A
600-1050° C. for Taor Nb and 600-95° C. for Ti

DI
600-800° C.

W(a)
250-400° C.

W(b)
600-1000° C., and

where W(a) designates the steady state temperature of the wheel taken diametrically opposite the abutment, and W(b) designates the steady state temperature of the wheel proximate the abutment.

17. The process of claim 14 , wherein the steady state temperatures are:

CR
less than 350° C.

SI
600-630° C.

Assignees

• Wilson Robert Simon
• Yousuff Merchant
• Stone Nigel Austin
• Ritchie David James Bell
• Cantin Gersende Marie Delphine
• Gibson Mark Antony
• Thomas Ian Curtis
• Commw Scient Ind Res Org

Inventors

• Wilson Robert Simon
• Yousuff Merchant
• Stone Nigel Austin
• Ritchie David James Bell
• Cantin Gersende Marie Delphine
• Gibson Mark Antony
• Thomas Ian Curtis

Classifications

• B22F3/20

  by extruding · CPC title

• B33Y30/00

  Apparatus for additive manufacturing; Details thereof or accessories therefor · CPC title

• B21C23/00 Primary

  Extruding metal; Impact extrusion · CPC title

• B22F2999/00

  Aspects linked to processes or compositions used in powder metallurgy · CPC title

• B21C23/005 Primary

  Continuous extrusion starting from solid state material (B21C23/008 takes precedence) · CPC title