EP0165732A1 - Titanium nitride dispersion strengthened bodies - Google Patents

Titanium nitride dispersion strengthened bodies Download PDF

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Publication number
EP0165732A1
EP0165732A1 EP85303822A EP85303822A EP0165732A1 EP 0165732 A1 EP0165732 A1 EP 0165732A1 EP 85303822 A EP85303822 A EP 85303822A EP 85303822 A EP85303822 A EP 85303822A EP 0165732 A1 EP0165732 A1 EP 0165732A1
Authority
EP
European Patent Office
Prior art keywords
bodies
powder
titanium
hydrogen
titanium nitride
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP85303822A
Other languages
German (de)
French (fr)
Other versions
EP0165732B1 (en
Inventor
Lionel Houston Ford
Eric George Wilson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
UK Atomic Energy Authority
Original Assignee
UK Atomic Energy Authority
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by UK Atomic Energy Authority filed Critical UK Atomic Energy Authority
Publication of EP0165732A1 publication Critical patent/EP0165732A1/en
Application granted granted Critical
Publication of EP0165732B1 publication Critical patent/EP0165732B1/en
Expired legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C32/00—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ
    • C22C32/0047—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with carbides, nitrides, borides or silicides as the main non-metallic constituents
    • C22C32/0068—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with carbides, nitrides, borides or silicides as the main non-metallic constituents only nitrides
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C1/00—Making non-ferrous alloys
    • C22C1/10—Alloys containing non-metals

Definitions

  • This invention relates to the production of titanium nitride dispersion strengthened bodies.
  • a method of production of a titanium nitride dispersion strengthened body involves the steps of producing a porous body from titanium containing alloy powder and then causing a flowing mixture of nitrogen and hydrogen to permeate the permeable matrix of powder particles so formed so as to effect nitriding of the titanium.
  • said porous body is produced by heating the powder in a hydrogen - containing atmosphere to achieve partial sintering, ie. sintering of the particles to such an extent that the body or matrix is permeable to the nitrogen/hydrogen gas flow and is sufficiently self-supporting to withstand the flow pressure.
  • a suitable temperature for the partial sintering is in the range of 900-1250°C.
  • the initial porous bodies are preferably disc-shaped and may be formed by heating the powder in the container in which it is to be nitrided, or in a separate container of similar shape.
  • Another method of producing the porous sinter may be by causing the powder, in a semi-molten atomised form, to impinge and accumulate on a collecting plate.
  • the bodies so formed will tend to be irregular in shape and may need machining to fit the nitriding container.
  • porous sinter must have sufficient strength not to disintegrate during the nitriding stage and sufficient interconnected porosity to allow access of the nitriding gas.
  • a suitable temperature for nitriding is in the range 1000 to 1150°C. After nitriding the body is preferably degassed in hydrogen to reduce the excess nitrogen in solid solution.
  • the nitrided alloy is used in the production of a tie bar of round section.
  • the alloy powder may initially be produced as a plurality of disc-shaped green compacts which are then subjected to the aforesaid partial sintering and nitriding steps. Thereafter a quantity of the discs so formed may be inserted into an extrusion container and consolidated, by extrusion, into a round-section rod or bar.
  • a quantity of the porous bodies may be consolidated, eg. by a rolling technique, into sheet form. It will be understood that various other methods of consolidating quantities of the porous bodies into desired shapes may be employed.
  • the porous bodies may once again be reduced to powder, as by comminuting, for use in conventional powder metallurgy forming techniques. It is thought that the nitrided powder will exhibit less susceptibility to oxidation at room temperatures than titanium oxide dispersion-strengthened powders which require special handling, eg. in inert atmospheres, to prevent oxidation at room temperatures.
  • the invention has particular application to the nitriding of titanium-containing austenitic and ferritic steel powders, especially 20% Cr/25% Ni/Ti powder.
  • a titanium-containing steel powder-formed body which has been produced in accordance with the method of the invention.
  • the invention also extends to components consolidated from said bodies and to powder derived by comminution of said bodies.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
  • Powder Metallurgy (AREA)
  • Manufacture Of Alloys Or Alloy Compounds (AREA)

Abstract

A porous body of titanium-containing alloy powder is heated first in a hydrogen-containing atmosphere to sinter the powder and to render it porous, and then in nitrogen/hydrogen to nitride the powder.

Description

  • This invention relates to the production of titanium nitride dispersion strengthened bodies.
  • The strengthening of titanium containing alloys by gas-phase nitriding to produce a dispersion of titanium nitride is now an established procedure but the nitriding of thick sections remains a problem because the kinetics are so slow.
  • According to the present invention a method of production of a titanium nitride dispersion strengthened body involves the steps of producing a porous body from titanium containing alloy powder and then causing a flowing mixture of nitrogen and hydrogen to permeate the permeable matrix of powder particles so formed so as to effect nitriding of the titanium.
  • Preferably said porous body is produced by heating the powder in a hydrogen - containing atmosphere to achieve partial sintering, ie. sintering of the particles to such an extent that the body or matrix is permeable to the nitrogen/hydrogen gas flow and is sufficiently self-supporting to withstand the flow pressure. A suitable temperature for the partial sintering is in the range of 900-1250°C.
  • The initial porous bodies are preferably disc-shaped and may be formed by heating the powder in the container in which it is to be nitrided, or in a separate container of similar shape.
  • Another method of producing the porous sinter may be by causing the powder, in a semi-molten atomised form, to impinge and accumulate on a collecting plate. The bodies so formed will tend to be irregular in shape and may need machining to fit the nitriding container.
  • As previously mentioned the porous sinter must have sufficient strength not to disintegrate during the nitriding stage and sufficient interconnected porosity to allow access of the nitriding gas.
  • A suitable temperature for nitriding is in the range 1000 to 1150°C. After nitriding the body is preferably degassed in hydrogen to reduce the excess nitrogen in solid solution.
  • In one example of the invention, the nitrided alloy is used in the production of a tie bar of round section. In this case, the alloy powder may initially be produced as a plurality of disc-shaped green compacts which are then subjected to the aforesaid partial sintering and nitriding steps. Thereafter a quantity of the discs so formed may be inserted into an extrusion container and consolidated, by extrusion, into a round-section rod or bar.
  • In another example, a quantity of the porous bodies may be consolidated, eg. by a rolling technique, into sheet form. It will be understood that various other methods of consolidating quantities of the porous bodies into desired shapes may be employed.
  • If desired, after nitriding the porous bodies may once again be reduced to powder, as by comminuting, for use in conventional powder metallurgy forming techniques. It is thought that the nitrided powder will exhibit less susceptibility to oxidation at room temperatures than titanium oxide dispersion-strengthened powders which require special handling, eg. in inert atmospheres, to prevent oxidation at room temperatures.
  • The invention has particular application to the nitriding of titanium-containing austenitic and ferritic steel powders, especially 20% Cr/25% Ni/Ti powder. Thus, according to a further aspect of the invention there is provided a titanium-containing steel powder-formed body which has been produced in accordance with the method of the invention. The invention also extends to components consolidated from said bodies and to powder derived by comminution of said bodies.

Claims (11)

  1. I. A method of production of a titanium nitride dispersion strengthened body characterised by the steps of producing a porous body from titanium containing alloy powder and then causing a flowing mixture of nitrogen and hydrogen to permeate the permeable matrix of powder particles so formed so as to effect nitriding of the titanium.
  2. 2. A method according to Claim 1, characterised in that the porous body is produced by heating the powder in a hydrogen-containing atmosphere to achieve partial sintering to the extent that the matrix is both permeable to the flow of nitrogen/hydrogen mixture and is sufficiently self-supporting to withstand the flow pressure.
  3. 3. A method according to Claim 2, characterised in that the partial sintering is carried out at a temperature within the range 900-1250°C.
  4. 4. A method according to any of the preceding Claims, characterised in that nitriding is carried out at a temperature within the range 1000-1150°C.
  5. 5. A method according to any of the preceding claims, characterised in that after the nitriding step the body Is degassed in hydrogen to reduce excess nitrogen in the solid solution.
  6. 6. A method according to any of the preceding Claim, Characterised by the further steps, to produce a structural article of round section, of subjecting a plurality of said bodies which are of disc-shaped form to consolidation and extrusion.
  7. 7. A method according to any of Claims 1-5, characterised by the further step, to produce a structural article in sheet form, of subjecting a plurality of said bodies to consolidation by rolling out into sheet.
  8. 8. A method according to any of Claims 1-5, characterised by the further steps of comminuting a plurality of said bodies and forming structural articles to desired shapes by conventional powder metallurgy forming techniques.
  9. 9. Titanium nitride dispersion strengthened bodies characterised by having been produced by a method according to any of the preceding claims.
  10. 10. A titanium-containing steel powder-formed body characterised by having been produced by a method according to any of the preceding claims.
  11. 11. Structural components of or incorporating titanium nitride dispersion strengthened bodies according to Claims 9 or 10.
EP85303822A 1984-06-15 1985-05-30 Titanium nitride dispersion strengthened bodies Expired EP0165732B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB8415289 1984-06-15
GB8415289 1984-06-15

Publications (2)

Publication Number Publication Date
EP0165732A1 true EP0165732A1 (en) 1985-12-27
EP0165732B1 EP0165732B1 (en) 1989-01-04

Family

ID=10562490

Family Applications (1)

Application Number Title Priority Date Filing Date
EP85303822A Expired EP0165732B1 (en) 1984-06-15 1985-05-30 Titanium nitride dispersion strengthened bodies

Country Status (3)

Country Link
EP (1) EP0165732B1 (en)
JP (1) JPS613865A (en)
DE (1) DE3567227D1 (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3624622A1 (en) * 1986-07-21 1988-02-25 Feichtinger Heinrich K METHOD AND DEVICE FOR PRODUCING METALLIC MATERIALS BY HOT ISOSTATIC PRESSING OF METAL POWDER
US6231807B1 (en) 1998-02-04 2001-05-15 Sandvik Ab Dispersion hardening alloy and method for the production of the alloy
ES2163344A1 (en) * 1998-07-31 2002-01-16 Univ Catalunya Politecnica Nickel and titanium alloys medical nitriding technique consists of gaseous surface treatment to give good wear and friction factors in e.g. orthop
US6416871B1 (en) 1999-05-27 2002-07-09 Sandvik Ab Surface modification of high temperature alloys
GB2492054A (en) * 2011-06-13 2012-12-26 Charles Malcolm Ward-Close Adding or removing solute from a metal workpiece and then further processing
WO2013097205A1 (en) * 2011-12-28 2013-07-04 成都易态科技有限公司 Method for adjusting pore size of porous metal material and pore structure of porous metal material

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2933386A (en) * 1956-08-01 1960-04-19 Rca Corp Method of sintering and nitriding ferrous bodies
GB1434729A (en) * 1972-11-01 1976-05-05 Gkn Group Services Ltd Method of making an austenitic steel artifact

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2933386A (en) * 1956-08-01 1960-04-19 Rca Corp Method of sintering and nitriding ferrous bodies
GB1434729A (en) * 1972-11-01 1976-05-05 Gkn Group Services Ltd Method of making an austenitic steel artifact

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3624622A1 (en) * 1986-07-21 1988-02-25 Feichtinger Heinrich K METHOD AND DEVICE FOR PRODUCING METALLIC MATERIALS BY HOT ISOSTATIC PRESSING OF METAL POWDER
US6231807B1 (en) 1998-02-04 2001-05-15 Sandvik Ab Dispersion hardening alloy and method for the production of the alloy
ES2163344A1 (en) * 1998-07-31 2002-01-16 Univ Catalunya Politecnica Nickel and titanium alloys medical nitriding technique consists of gaseous surface treatment to give good wear and friction factors in e.g. orthop
US6416871B1 (en) 1999-05-27 2002-07-09 Sandvik Ab Surface modification of high temperature alloys
GB2492054A (en) * 2011-06-13 2012-12-26 Charles Malcolm Ward-Close Adding or removing solute from a metal workpiece and then further processing
WO2013097205A1 (en) * 2011-12-28 2013-07-04 成都易态科技有限公司 Method for adjusting pore size of porous metal material and pore structure of porous metal material

Also Published As

Publication number Publication date
EP0165732B1 (en) 1989-01-04
DE3567227D1 (en) 1989-02-09
JPS613865A (en) 1986-01-09

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