摘要:
A hollow article is made by providing and diffusion bonding the opposing parts of an article made of an alpha-beta titanium alloy. Hydrogen is introduced into the surface of an internal cavity before, during, or after diffusion bonding. The article is heat treated with the hydrogen present, typically by solution treating and aging the hydrogen-containing bonded article. The result is the production of a microstructure at the internal surface of the cavity that is resistant to fatigue-crack initiation, while retaining a microstructure throughout the rest of the article that is resistant to fatigue-crack propagation. After heat treating, the hydrogen Is removed from the article, and any further heat treating and other operations are completed.
摘要:
Enhanced crystallographic texture is developed in an alpha or alpha-beta titanium alloy having a dispersion of particles therein, by heating the alloy to essentially the all beta phase range and mechanically hot working the alloy in this range. The mechanical working is preferably accomplished by extrusion, rolling, or forging. The particles are stable during working, and prevent the formation of random texture in recrystallized beta phase grains at the working temperature. The particles are preferably oxides formed from rare earth elements such as erbium or yttrium, that are introduced into the alloy during manufacture. The alloys processed according to the invention are preferably prepared by powder metallurgy to achieve a uniform microstructure prior to working. A particularly suitable alpha-beta (but near alpha) titanium alloy contains aluminum, zirconium, hafnium, tin, columbium, molybdenum, tungsten, ruthenium, germanium, silicon, and erbium.
摘要:
An alpha-beta titanium-base alloy is heat treated to improve its dwell fatigue properties while retaining a good balance of mechanical properties. The heat treatment includes first heating the alpha-beta titanium-base alloy to a first heat-treatment temperature in a first range of from about 70° F. below a beta transus temperature of the alpha-beta titanium-base alloy to the beta transus temperature of the alpha-beta titanium-base alloy, and quenching the alpha-beta titanium-base alloy at a rate of greater than about 200° F. per minute. The alpha-beta titanium-base alloy is second heated to a second heat-treatment temperature in a second range of from about 100° F. to about 400° F. below the beta transus temperature of the alpha-beta titanium-base alloy, and thereafter cooling the alpha-beta titanium-base alloy to ambient temperature at a rate of from about 10° F. per minute to about 200° F. per minute.
摘要:
A hollow article is made by providing and diffusion bonding the opposing parts of an article made of an alpha-beta titanium alloy. Hydrogen is introduced into the surface of an internal cavity before, during, or after diffusion bonding. The article is heat treated with the hydrogen present, typically by solution treating and aging the hydrogen-containing bonded article. The result is the production of a microstructure at the internal surface of the cavity that is resistant to fatigue-crack initiation, while retaining a microstructure throughout the rest of the article that is resistant to fatigue-crack propagation. After heat treating, the hydrogen is removed from the article, and any further heat treating and other operations are completed.
摘要:
A metallic article is prepared by first furnishing at least one nonmetallic precursor compound, wherein all of the nonmetallic precursor compounds collectively containing the constituent elements of the metallic article in their respective constituent-element proportions. The constituent elements together form a titanium-base alloy having a stable-oxide-forming additive element therein, such as magnesium, calcium, scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium, and mixtures thereof. The stable-oxide-forming additive element forms a stable oxide in a titanium-based alloy. At least one additive element is present at a level greater than its room-temperature solid solubility limit in the titanium-base alloy. The precursor compounds are chemically reduced to produce an alloy material, without melting the alloy material. The alloy material may be consolidated. The alloy material, or consolidated metallic article, is thereafter desirably exposed to an oxygen-containing environment at a temperature greater than room temperature.
摘要:
An article includes a microscale composite material having a matrix with titanium boride particles configured to form an insert in a metallic mass being comprised of material other than a consolidated titanium-based metallic composition having titanium particles.
摘要:
A metallic article is produced by furnishing one or more nonmetallic precursor compound comprising the metallic constituent element(s), and chemically reducing the nonmetallic precursor compound(s) to produce an initial metallic particle, preferably having a size of no greater than about 0.070 inch, without melting the initial metallic particle. The initial metallic particle is thereafter melted and solidified to produce the metallic article. By this approach, the incidence of chemical defects in the metal article is minimized. The melted-and-solidified metal may be used in the as-cast form, or it may be converted to billet and further worked to the final form.
摘要:
An article includes a microscale composite material having a matrix with titanium boride particles configured to form an insert in a metallic mass being comprised of material other than a consolidated titanium-based metallic composition having titanium particles.
摘要:
A metallic component, which may be an airfoil, includes at least one treated patch, wherein the entire thickness of the component within the treated patch is in a state of residual compressive stress. A surface-treated area overlaps at least a boundary between the treated patch and the remainder of the component. The surface of the component within the surface-treated area is in a state of residual compressive stress, so as to resist crack initiation at the boundary between the treated patch and the remainder of the component. A method is also provided for making such a component.
摘要:
A metallic component is by at least one peripheral edge. The component includes at least one elongated treated zone having a length substantially greater than its width. This treated zone is spaced away from and disposed generally parallel to the peripheral edge of the component and the entire thickness of the component within the treated zone is in a state of residual compressive stress. Crack growth from the edge due to fatigue or damage is resisted.