EP0571595A1 - Alliage de magnesium contenant du titane obtenu par refroidissement brusque de vapeur - Google Patents

Alliage de magnesium contenant du titane obtenu par refroidissement brusque de vapeur

Info

Publication number
EP0571595A1
EP0571595A1 EP19920924804 EP92924804A EP0571595A1 EP 0571595 A1 EP0571595 A1 EP 0571595A1 EP 19920924804 EP19920924804 EP 19920924804 EP 92924804 A EP92924804 A EP 92924804A EP 0571595 A1 EP0571595 A1 EP 0571595A1
Authority
EP
European Patent Office
Prior art keywords
titanium
magnesium
alloys
alloy
corrosion
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.)
Ceased
Application number
EP19920924804
Other languages
German (de)
English (en)
Inventor
David John Bray
Robert William Gardiner
Brian William Viney
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 Secretary of State for Defence
Original Assignee
UK Secretary of State for Defence
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 Secretary of State for Defence filed Critical UK Secretary of State for Defence
Publication of EP0571595A1 publication Critical patent/EP0571595A1/fr
Ceased legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
    • C23C14/24—Vacuum evaporation
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C23/00—Alloys based on magnesium
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
    • C23C14/14—Metallic material, boron or silicon
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating

Definitions

  • This invention relates to alloys which are based upon magnesium and contain titanium, which are produced by the technique of vapour quenching. These alloys yield improved resistance to corrosion in comparison with existing alloys of magnesium.
  • Magnesium is the lightest of the structural metals and has significant potential utility for aerospace applications, but magnesium alloys have somewhat fallen out of favour for use in such applications, partly because of poor compression properties, but principally because of their poor corrosion resistance.
  • Conventional magnesium alloys (that is those produced by ingot metallurgy methods) have generally poor corrosion resistance due primarily to the water-solubility of the Mg(0H) 2 film which forms on the alloy in damp environments. This problem of surface corrosion is exacerbated by electrochemical effects as magnesium has a large negative electrode potential.
  • the presence of particles containing common impurity elements such as iron, copper and nickel which have a less negative electrode potential leads to a susceptibility to pitting and general corrosion.
  • Magnesium alloys are also subject to electrochemical corrosion when joined to other structural metals as most have a significantly different electrode potential.
  • alloying Ingredients utilised in alloys other than magnesium alloys have minimal or no solubility within magnesium in the melt because of the low boiling point of magnesium and the binary phase diagrams of magnesium with these materials are unknown.
  • USA patent 4264362 discloses a prior magnesium - titanium alloy produced in the solid state by a mechanical alloying process.
  • the alloys disclosed in that specification were alloys in which neither of the two elements was present in solid solution within the other (the two being in the state of a mechanical mixture of the elements) and the alloy product was a supercorroding material intended to react quickly with sea water to provide exothermic heating.
  • GB patent 1,382,970 discloses a magnesium-based corrosion resistant alloy additionally comprising aluminium, zinc, manganese and titanium as well as minute amounts of various doping agents.
  • the alloys disclosed in this document are produced by conventional ingot metallurgy and hence those alloys containing titanium do not have the titanium constituent in solid solution.
  • GB patent 1,011,585 discloses corrosion resistant magnesium alloys incorporating, in one example, up to 3% titanium suicide.
  • US patent 5.024,813 discloses magnesium-titanium alloys produced by a powder-metallurgical route from a mixtue of magnesium, titanium and titanium hydride powders.
  • the compositions disclosed are very broad, ranging from 0.04 to 99- 6 wt of titanium.
  • the sintered products are not fully dense and therefore doubts remain concerning the structural properties of these alloys. It is therefore an object of this invention to provide a magnesium alloy which provides an improvement in corrosion resistance beyond the level available in current commercial alloys. To achieve this a reduction in both susceptibility to weight loss in saline environments and to electrochemical corrosion (by reduction in its electrode potential) is desirable.
  • Vapour quenching is a known physical vapour deposition technique which is used primarily for the production of metal films or coatings but is also known as a route to the production of alloys having metastable supersaturated solid solutions on a scale suitable for quite significant structural applications.
  • This invention is concerned with the latter application of vapour quenching technology. The process is performed by evaporating alloy constituents from individual or combined sources to produce a flux of vapours, and causing these vapours to be condensed upon a collector which is controlled in temperature to a value which causes extremely rapid quenching of the impinging vapours. All this takes place within a vacuum chamber.
  • vapour quenching process for the production of alloys is given in two articles by Bickerdike et al in the International Journal of Rapid Solidification, 1985. volume 1 pp 305-325; and 1986, volume 2, pp 001-019.
  • the collector deposit obtained by vapour quenching can be utilised in various product forms. It can be taken from the collector and processed intact e.g. by forging, rolling, or hot pressing to yield a monolithic product or it can be comminuted to particulate form and subsequently canned and consolidated by hot isostatic pressing or extrusion.
  • the invention claimed herein is a magnesium based alloy produced by vapour quenching which comprises 0.5% to 47% of titanium by weight, wherein the titanium is substantially held in solid solution in the alloy as deposited.
  • magnesium alloys incorporating a variety of such ingredients using a vapour deposition process by evaporating the magnesium base and the alloying ingredients from separate sources and combining the vapour streams to yield an alloyed deposit on the collector.
  • magnesium - titanium alloys produced by this method are capable of yielding a particularly good resistance to corrosion.
  • the alloys have a titanium content in the range 5 to 40% by weight.
  • the magnesium alloy may contain, in addition to the titanium, other ingredients such as those used in prior art magnesium alloys within the following weight limits-
  • the titanium content of the alloy does not exceed 40% in alloys intended for duties where low density is important for at higher titanium contents the alloy density approaches that obtainable from other alloys such as aluminium-lithium alloys. But it should be noted that the resistance to corrosion and the electrode potential improves with Increasing titanium content so a high titanium content might be preferred for this reason.
  • a most preferred range of titanium in the alloy is 1 to 28%.
  • Practical ternary alloys might include titanium in the aforementioned preferred range with either approximately 5% aluminium (to yield a physically stronger magnesium based material still having good corrosion resistance) or else approximately 1% silicon (to increase corrosion resistance still further) . Alloys within the scope of the claims have demonstrated thermal stability (as ascertained by differential scanning calorimetry) up to 200 ⁇ C and can be processed from comminuted particulate form by first canning the particulate and then extruding or hot isostatic pressing this.
  • Figure 1 is a schematic cross sectional view of one form of small scale evaporation equipment
  • Figure 2 is a schematic cross sectional view of a second form of evaporation equipment
  • Figure 3 is a differential scanning calorimetry plot showing the thermal stability for a test sample of AS32 magnesium- titanium alloy heated over a temperature range of 50 to 500°C at a rate of 10°/minute
  • Figure 4 is a plot showing the corrosion resistance of heat treated sample of the magnesium-titanium alloy
  • Figure 5 is a plot comparing the composition and density for the magnesium-titanium alloy.
  • the apparatus has separate evaporators for the magnesium and titanium charges.
  • the evaporator for the titanium charge comprises a water-cooled copper crucible 1 with an underside opening 2 through which is fed a rod charge of titanium 3 and there is an electron beam gun 4 which is beam steered so that the electrons impinge upon the topmost end of the rod charge 3 to cause this to be melted locally.
  • a stream of titanium vapour 5 issues from the melt pool in an upward direction towards a collector 6 and the flux of vapours is controlled by adjustment to the power setting of the electron beam gun 4.
  • the evaporator for the magnesium base constituent of the alloy is a heated block 7 of metal of a generally "U" shaped configuration which Is located above the level of the titanium source crucible 1 and is of a size and is positioned such that it encompasses the rising flux of titanium vapour on three sides thereof.
  • Block 7 has an inwardly directed slot 8 within which solid charge pieces 9 of magnesium are placed and the block 7 is heated by means of a radiant heater 10, extending through the mass of the block, to a temperature at which magnesium vapour issues forth from the charge pieces 9 by sublimation.
  • These vapours issue forth laterally through the slot opening to converge upon the rising flux of titanium vapour and vapqur mixing takes place by mingling of the vapour streams and by atomic collisions. Some of the intermixed vapours rise upwards to condense upon the collector 6 to yield a deposit 11.
  • the collector is heated to and maintained at a suitable temperature to ensure that the impinging vapours are quenched to produce an appropriate microstrueture in the alloy deposit 11.
  • a shutter 12 which is closed in the warm up period of operation of the equipment and opened when the equipment stabilises. This is a safeguard measure intended to avoid unwanted collection of deposits having the wrong composition.
  • Variation of composition is achieved through alteration of the respective rates of generation of the titanium and magnesium vapours.
  • the electron beam gun power is varied within the range given above to increase or decrease the flux of titanium vapours and the temperature to which the magnesium source is heated is varied (but remaining below the melting temperature) to increase or decrease the flux of magnesium vapour. Simultaneous manipulation of both these provides control over the alloy deposition rate.
  • This second form of equipment comprises an inner evaporation crucible 31 surrounded by a another evaporation crucible 32.
  • a charge 33 of the titanium is contained within the crucible 31 *
  • This crucible is open topped and the charge of titanium within it is heated by means of an electron beam 37-
  • This electron beam 37 is focussed and steered by means of a magnet 38 to impinge upon the uppermost surface of the charge 33 to heat it to a temperature at which an appreciable flux of titanium vapours escapes from the charge.
  • the other evaporation crucible 3 holds a charge 3*** of magnesium within it and this charge is heated by a radiant heater 39-
  • Crucible 32 has a lid 40 and there are nozzles 4l present in the lid through which a flux of magnesium vapours issues forth.
  • the two crucibles are placed as depicted (one within the other) beneath a collector 35-
  • the nozzles 4l are so directed as to cause the individual streams of magnesium vapours to converge towards each other on paths which intersect the direct path between the other evaporator 31 and the collector 35 so that vapour mixing between the two species of vapours occurs before either species lands upon the collector.
  • a deposit 36 of alloy is built up on the lower surface of the collector 35-
  • the lid 40 is heated by a separate radiant heater 42 to a higher temperature than that of the magnesium charge.
  • the nozzles are of re-entrant form as depicted in the figure and by this combination of re-entrant form and higher temperature, condensation within or upon the nozzle of magnesium vapours is minimised.
  • the nozzles 4l serve the dual function of directing the streams of magnesium vapours and choking the volume flow-rate somewhat allowing the magnesium charge to be superheated to yield sufficient vapour pressure to disperse surface oxide contaminants from the surface of the melt without saturating the deposit with an excess of magnesium.
  • the evaporator 32 is charged with pieces of magnesium and heated to produce a melt of metal at a temperature of approximately 750°C.
  • the temperature of the titanium charge 33 within evaporator 31 is not controlled directly, instead control of titanium evaporation rate and hence of alloy deposit composition Is achieved by variation of electron beam power up to a maximum power of 20 kW.
  • Ternary and more complex alloys can be produced by this second equipment by using a different form of inner crucible 31 accepting an under-fed rod source in the manner of the first type of equipment, and using a pre-alloyed titanium alloy rod charge of appropriate composition.
  • Vapour-quenched magnesium-titanium binary alloys to the following compositions have been produced by means of the two equipments described above. All compositions are given in proportions by weight.
  • Corrosion resistance tests have been performed on various examples of the claimed alloy and also a comparison specimen of pure magnesium prepared by the same vapour quenching route. These materials were all tested in the as-deposited condition. Some other comparison materials were tested also in their normal commercially available form. These additional comparison materials are listed below: WE 43 (nominal composition: Mg base - 4%Y - 3 Nd + other rare earths - 0.5%Zr); AZ91E (nominal composition: Mg base - 9%A1 - 0.5%Zr - 0.3%Mn); and EA55RS a rapid solidification route alloy (nominal composition: Mg base - 5%A1 - 5%Zn - 5%Nd) .
  • the corrosion resistance tests comprised a.
  • the other aspect to corrosion resistance is the electrode potential exhibited by the material. This value has been measured for the alloy examples listed below.
  • the values of electrode potential given represent the open circuit potential (relative to a standard saturated calomel electrode) exhibited by the alloys in a 600mM/l solution of sodium chloride after 30 minutes immersion therein.
  • the thermal stability of the alloys is important because most applications require use at temperatures significantly above room temperature and it is important that there is no degradation in mechanical properties and corrosion resistance.
  • An early indication of the thermal stability of these alloys can be obtained from differential scanning calorimetry (DSC) .
  • DSC of these magnesium titanium alloys indicates that their short term stability extends to at least 230°C as is shown in Figure 3-
  • Maintaining the low density of magnesium alloys is important for aerospace applications. It is essential that the levels of titanium required to reduce the corrosion rate of the alloys do not increase the density to unacceptable levels. Analysis shows a maximum value of around 2.1 g/cm 3 should be an objective for these alloys. Measurements of the density of the deposited alloys, when compared with the accepted value for pure magnesium and values calculated from lattice parameter measurement, suggest that there is some porosity but that alloys containing less than around 28 wt%. of titanium should have good specific properties. This is shown in the table below and also in Figure 5- The corrosion tests results indicate that an upper limit of 28% titanium should not limit the development of a good corrosion resistant alloy.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Manufacture Of Metal Powder And Suspensions Thereof (AREA)

Abstract

Un alliage à base de magnésium contenant 0,5 à 47 % de titane en poids est produit sous la forme d'une solution solide par refroidissement brusque de vapeur. Les ingrédients sont volatilisés à partir de sources distinctes pour éviter le problème de l'insolubilité du titane dans le magnésium en fusion. Les gammes préférées pour le titane sont de 5 à 40 % et de 15 à 28 % en poids. L'alliage est résistant à la corrosion, en particulier aux teneurs élevées en titane. On décrit des alliages contenant 15 à 28 % de titane et soit 5 % environ d'aluminium, soit 1 % environ de silicium. Les alliages peuvent contenir d'autres éléments conventionnels utilisés comme ingrédients des alliages à base de magnésium.
EP19920924804 1991-12-16 1992-12-09 Alliage de magnesium contenant du titane obtenu par refroidissement brusque de vapeur Ceased EP0571595A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB9126619A GB2262539A (en) 1991-12-16 1991-12-16 Titanium containing magnesium alloy produced by vapour quenching.
GB9126619 1991-12-16

Publications (1)

Publication Number Publication Date
EP0571595A1 true EP0571595A1 (fr) 1993-12-01

Family

ID=10706308

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19920924804 Ceased EP0571595A1 (fr) 1991-12-16 1992-12-09 Alliage de magnesium contenant du titane obtenu par refroidissement brusque de vapeur

Country Status (5)

Country Link
EP (1) EP0571595A1 (fr)
JP (1) JPH06506505A (fr)
CA (1) CA2104012A1 (fr)
GB (1) GB2262539A (fr)
WO (1) WO1993012262A1 (fr)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU3708495A (en) 1994-08-01 1996-03-04 Franz Hehmann Selected processing for non-equilibrium light alloys and products
EP1260528A1 (fr) 2001-05-21 2002-11-27 Borealis Technology OY Tuyaux de polypropylène pour des pipelines
EP1260545A1 (fr) 2001-05-21 2002-11-27 Borealis Technology OY Système industriel de conduite en polyolèfine
US7651732B2 (en) * 2007-09-07 2010-01-26 Gm Global Technology Operations, Inc. Magnesium-titanium solid solution alloys
DE102013108997A1 (de) * 2013-08-20 2015-02-26 Von Ardenne Gmbh Tiegelanordnung und Vakuumbeschichtungsanlage
CN105401030A (zh) * 2015-11-10 2016-03-16 太仓捷公精密金属材料有限公司 一种耐腐蚀的钛镁合金材料
CN108456813B (zh) * 2018-01-22 2020-02-21 上海交通大学 一种Mg-Li-Al-Zn-Y系铸造镁锂合金及其热处理方法
CN111118364B (zh) * 2020-01-16 2021-08-24 江苏理工学院 一种可快速时效强化的Mg-Y-Nd-Gd-Zr-Li合金及其制备方法

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2178582A (en) * 1936-11-23 1939-11-07 Dow Chemical Co Magnesium alloy
US2340795A (en) * 1942-03-25 1944-02-01 Wander Company Magnesium alloy
US3240593A (en) * 1961-06-02 1966-03-15 Knapsack Ag Corrosion resistant magnesium alloys having a grain-refined structure
GB1382970A (en) * 1973-09-04 1975-02-05 Tikhonova V V Magnesium based alloys
US4264362A (en) * 1977-11-25 1981-04-28 The United States Of America As Represented By The Secretary Of The Navy Supercorroding galvanic cell alloys for generation of heat and gas
JPH0617524B2 (ja) * 1988-11-08 1994-03-09 勝廣 西山 マグネシウム―チタン系焼結合金およびその製造方法
GB2230792A (en) * 1989-04-21 1990-10-31 Secr Defence Multiple source physical vapour deposition.
GB2252979A (en) * 1991-02-25 1992-08-26 Secr Defence A metastable solid solution titanium-based alloy produced by vapour quenching.

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9312262A1 *

Also Published As

Publication number Publication date
JPH06506505A (ja) 1994-07-21
CA2104012A1 (fr) 1993-06-17
GB9126619D0 (en) 1992-02-12
WO1993012262A1 (fr) 1993-06-24
GB2262539A (en) 1993-06-23

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