Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C14/00—Alloys based on titanium

Definitions

• this invention provides such an alloy having such combination of properties, and this alloy consists essentially of by weight from 5.5% to 6.5% aluminum, from 1.7% to 2.3% tin, from 0.7% to 5% zirconium, from 0.7% to 3.0% molybdenum, and up to 0.2 oxygen, balance substantially titanium and incidental impurities.
• a preferred alloy consists essentially of about 6% aluminum, about 2% tin, about 2% zirconium and about 1% molybdenum, up to 0.12% oxygen, balance substantially titanium.
• Another preferred alloy consists essentially of about 6% aluminum, about 2% tin, about 4% zirconium, about 2% molybdenum, up to 0.12% oxygen, balance substantially titanium.
• the latter alloy is slightly stronger than the former, and is most useful where it strength is valuable in spite of its slightly increased density.
• the alloying elements present 'within the defined ranges are necessary to provide the combination effect resulting in the mechanical properties of the alloy of this invention.
• the percentages of alloy constituents referred to herein are in all cases percent by weight.
• the tin content of the alloy of this invention acts to supplement the aluminum in providing high elevated temperature strength without adverse effect on ductility. Less than 1.7% tin will not provide suflicient of this metal for its effect to be evident, and over 2.3% will be more than required to produce its optimum advantageous effect and also will have adverse effect on the specific gravity of the alloy.
• Zirconium functions more as an alpha stabilizer
• molybdenum which is beta stabilizer.
• the amount of molybdenum is also critical since sufiicient must be employed to increase solid solution strengthening and to provide the small amount of beta phase necessary for some heat treatability. Therefore, the amount present should not be less than 0.7% to obtain these results, and more than 3.0% should not be incorporated since the additional retained beta phase will adversely affect weldability and to some extent creep resistance.
• molybdenum is a heavy element, twice the specific gravity of titanium, and should be employed only up to an amount at which its benefits more than offset its weight increasing disadvantages.
• the oxygen content of the alloy of this invention is also critical and should be present in amount only up to 0.20% and preferably for elevated temperature applications should be present in amount up to 0.16%. Titanium and alloying elements suitable for production of alloys containing less than about 0.08% oxygen are not as readily available and will be often more expensive than those with higher oxygen content.
• the oxygen content for best stability and elevated temperature properties should be present in amount only up to about a 0.16% and preferably only up to about 0.12%. Oxygen in amount from 0.08% to 0.12% will provide a practical composition within the capability of high grade low oxygen titanium sponge used as a base material.
• Oxygen will be found as a constituent in the titanium metal and alloying metals employed to produce the alloy of this invention, and also may be absorbed by the alloy during various phases of preparation as, for example, melting.
• the oxygen pickup during preparation and melting of the alloy can generally be predicted within reasonable limits and titanium sponge and alloying elements or master alloys can be selected with oxygen content to produce an alloy containing oxygen Within the stated limits.
• oxygen below the upper limit as stated is critical to obtain the mechanical properties described, but its presence in some amount, at least a few hundredths of one percent, will be unavoidable using commercial titanium sponge and alloying elements and normally employed melting procedures.
• Incidental impurities may be present in the alloy of this invention in amounts associated as impurities in the titanium and alloying metals used. These impurities should not total more than about 0.4% in the aggregate and with respect to the presence of any individual element should not affect the essential nature of the alloy and its properties as herein described. Interstitials, including carbon and nitrogen as well as oxygen should not exceed in the aggregate about 0.25% with the amount of oxygen within the more restricted limits as hereinbefore described.
• Density of the alloy of this invention will 'be between 0.16 and 0.17 lb. per cubic inch with the specific figure depending principally on the aluminum and molybdenum content. These elements are the lightest and heaviest respectively in the composition. This range of density includes that of commercially pure titanium, generally accepted to be 0.163 or 0.164 lb. per cubic inch.
• the characteristic strength of the alloy of this invention will in general be comparable to or better than the strength of other titanium base alloys such as, for example, those containing Al-2.5% Sn or 6% Al-4% V, balance titanium.
• the ultimate tensile strength will be at least 120,000 p.s.i. measured at 800 F. Yield strength will be good, in the range of 100,000 p.s.i. and higher; and ductility will be good as indicated by reduction in area and elongation values.
• the alloy provides high strength yet good ductility.
• an alloy according to this invention will show retention of ductility after exposure at elevated temperature under stress. Such retention of ductility is a measure of stability. Elevated temperature properties, particularly stability, will be characteristically good in an alloy of this invention even when the oxygen content is relatively high, that is, over 0.16% and up to 0.20%. However, for best properties and with no degradation of ductility when exposed, for example, for 150 hours at 1000 F. under stress of 30,000 p.s.i. the alloy should preferably contain only up to 0.16% oxygen.
• the alloy will show creep deformation of less than 0.60% when tested under the same conditions, that is, exposure to 30,000 p.s.i. for 150 hours at 1000 F.
• the alloy of this invention possesses an unique combination of valuable mechanical properties.
• Mechanical properties of the 6% Al-2% Sn-2% Zr-1% Mo type alloy according to this invention are such as to provide an alloy suitable for a variety of purposes. It may, for example, be employed in the manufacture of jet engines Where its strength, ductility and creep resistance are important. For airframe applications, its room and elevated temperature strength will be found advantageous.
• Density Density of 6% Al-2% Sn-2% Zr-l% Mo, balance titanium alloy is 0.162 lb. per cubic inch. This is comparable to unalloyed titanium and is lighter than many titanium base alloys containing high percentages of heavy metals such as vanadium, iron, molybdenum, columbium or taut-alum.
• the alloy of this invention shows good toughness both at room temperature and at 80 F.
• the tensile strength and ductility in heat treated condition are also good and these properties are not materially degraded in a welded area-note ductility indicated by RA of 38 and Elongation of 18 in the welded specimen.
• fNotch tensile strength determined at head speed of 0.05 inch pe r iligih time fracture is the maximum static stress the specimen will withstand for 5 hours without iailure (10 K p.s.i. increments, accuracy better than 1 K psi).
• the alloy of this invention may be produced by a convenient method by which the titanium and alloying elements are melted together to form a substantially homo geneous composition.
• titanium sponge of required purity and particularly with respect to its oxygen content is admixed with subdivided aluminum, tin, zirconium, and molybdenum in proper amounts and the mixture compressed into compacts. These compacts are welded together to form an electrode which is melted in a consumable electrode arc melting furnace to produce an ingot of alloy.
• the so-produced alloy ingot may be itself employed as an electrode in a subsequent remelting step to provide improved homogeneity in a final alloy ingot.
• a titanium base alloy consisting of from 5.5% to 6.5% aluminum, from 1.7% to 2.3% tin, from 0.7% to 5.0% zirconium, from 0.7% to 3.0% molybdenum, and up to 0.2% oxygen, balance titanium except for impurities
• a density between 0.16 and 0.17 lb. per cubic inch, an ultimate tensile strength measured at room temperature of at least 120,000 p.s.i., and stability with creep deformation less than 0.60% after exposure to 30,000 p.s.i. for 150 hours at 1000 F.
• a titanium base alloy consisting of from 5.5% to 6.5% aluminum, from 1.7% to 2.3% tin, from 0.7% to 5.0% zirconium, from 0.7% to 3.0% molybdenum, from 0.08% to 0.12% oxygen, balance titanium except for impurities within commercial tolerances, characterized by a density between 0.16 and 0.17 lb. per cubic inch, an ultimate tensile strength measured at room temperature of at least 120,000 p.s.i. and measured at 800 F. of at least 70,000 p.s.i., and substantially no degradation of ductility with creep deformation less than 0.60% after exposure to 30,000 p.s.i. for 150 hours at 1000 F.
• a titanium 'base alloy consisting of about 6% aluminum, about 2% tin, about 2% zirconium, about 1% molybdenum, up to 0.16% oxygen, balance titanium except for impurities Within commercial tolerances, characterized by a density of about 0.162 lb. per cubic inch,
• a titanium base alloy consisting of about 6% aluminum, about 2% tin, about 4% zirconium, about 2% molybdenum, up to 0.16% oxygen, balance titanium except for impurities within commercial tolerances, char- 0 acterized by a density of about 0.166 lb. per cubic inch,

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• Electric Double-Layer Capacitors Or The Like (AREA)
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• 1965
  • 1965-03-01 US US436268A patent/US3343951A/en not_active Expired - Lifetime
• 1966
  • 1966-02-25 DE DE19661533199 patent/DE1533199B1/de active Pending
  • 1966-02-25 FR FR51074A patent/FR89637E/fr not_active Expired
  • 1966-02-28 BE BE677115D patent/BE677115A/xx unknown
  • 1966-02-28 SE SE2575/66A patent/SE317518B/xx unknown
  • 1966-03-01 GB GB9001/66A patent/GB1095076A/en not_active Expired

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