Patents by Inventor Louis E. Dardi
Louis E. Dardi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 5312650Abstract: The method of making a composite article of different metal portions by spraying molten metal on the surface of a solid metal member that has been cleaned and preheated in a controlled atmosphere at low pressure. The molten metal is sprayed on the surface of the solid metal member, preferably by plasma jet spraying. It is rapidly solidified to be adherent to the surface of the solid metal member to form a composite preform. The composite preform is cooled at a rate sufficiently low to reduce residual stresses and then hot pressed to eliminate voids in the sprayed metal portion and metallurgically bonded to the surface of the solid member.Type: GrantFiled: January 12, 1988Date of Patent: May 17, 1994Assignee: Howmet CorporationInventors: Ranes P. Dalal, John M. McFadden, Mark J. Straszheim, Louis E. Dardi
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Patent number: 5273204Abstract: A method of joining metal materials by spraying molten metal into a cavity between the articles to be joined. Prior to deposition of the metal, the surface of the cavity is cleaned and the articles to be joined are preheated. Subsequent to deposition of the metal within the cavity, the joined articles are cooled at a rate that precludes damage due to thermal effects and the deposited metal is consolidated in the cavity by hot pressing.Type: GrantFiled: March 25, 1988Date of Patent: December 28, 1993Assignee: Howmet CorporationInventors: Ranes P. Dalal, John M. McFadden, Mark J. Straszheim, Louis E. Dardi
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Patent number: 4764225Abstract: A nickel- or cobalt-based alloy of the type containing, by weight, 5 to 40% chromium, up to about 10% aluminum, up to about 10% titanium, up to about 30%, in combination, of elements from the group tantalum, tungsten, molybdenum, columbium, rhenium, or vanadium, up to about 2% silicon, up to about 5% hafnium, and up to about 5% reactive elements such as lanthanum, yttrium or other rare earths. Manganese is present in an amount from 0.1 to 12%, preferably 0.5 to 4%. Silicon in amounts from 1.0 to 2.0 by weight, or hafnium in amounts from 0.1 to 5.0% by weight may also be used. Alloys in accordance with this invention are particularly suitable for casting by the single crystal technique; however, the alloys can also be used in the production of polycrystalline components such as directionally solidified, conventionally solidified (equiaxed), wrought, or dispersion strengthened materials. In the latter case, grain boundary modifiers such as carbon, boron, zirconium and hafnium are utilized.Type: GrantFiled: May 13, 1980Date of Patent: August 16, 1988Assignee: Howmet CorporationInventors: Srinivasan Shankar, Louis E. Dardi
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Patent number: 4624714Abstract: A method of refining the microstructure of metals which undergo a phase transformation at high temperatures by diffusing a solute material into the metal at a temperature below the normal transformation temperature. The solute induces the phase transformation and removal of the solute at a temperature near the transformation temperature reverses the transformation. These phase transformations refine the microstructure of the metal so treated. The method is particularly useful to Group IVB metals i.e. Zr, Hf and Ti.Type: GrantFiled: October 31, 1984Date of Patent: November 25, 1986Assignee: Howmet Turbine Components CorporationInventors: Robert J. Smickley, Louis E. Dardi
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Patent number: 4615864Abstract: Coatings for iron-, nickel- and cobalt-base superalloys. The coatings are applied in order to provide good oxidation and/or sulfidation and thermal fatigue resistance for the substrates to which the coatings are applied. The coatings consist essentially of, by weight, 10 to 50% chromium, 3 to 15% aluminum, 0.1 to 10% manganese, up to 8% tantalum, up to 5% tungsten, up to 5% reactive metal from the group consisting of lanthanum, yttrium and other rare earth elements, up to 5 percent of rare earth and/or refractory metal oxide particles, up to 12% silicon, up to 10% hafnium, and the balance selected from the group consisting of nickel, cobalt and iron, and combinations thereof. Additions of titanium up to 5% and noble metals up to 15% are also contemplated.Type: GrantFiled: April 23, 1982Date of Patent: October 7, 1986Assignee: Howmet Turbine Components CorporationInventors: Louis E. Dardi, Srinivasan Shankar
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Patent number: 4505764Abstract: The microstructure of titanium is refined by inducing a high temperature transformation from .alpha.+.beta. to .beta. and back to .alpha.+.beta. by diffusing hydrogen into and then out of the metal while maintaining the metal above the temperature of hydride formation. The titanium is heated to a temperature just below the .alpha.+.beta. to .beta. transformation temperature, and hydrogen is diffused into the metal thereby inducing the phase change. The hydrogen is diffused out of the metal again inducing a phase change. When the hydrogen has been removed, the metal is allowed to cool to room temperature.Type: GrantFiled: March 8, 1983Date of Patent: March 19, 1985Assignee: Howmet Turbine Components CorporationInventors: Robert J. Smickley, Louis E. Dardi
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Patent number: 4447503Abstract: Coatings for iron-, nickel- and cobalt-base superalloys and the resulting coated components having good high temperature oxidation resistance. The coatings consist essentially of, by weight, 5% to 50% chromium, 3% to 30% aluminum, 0.01% to 15% tantalum, up to 10% manganese, up to 5% tungsten, up to 12% silicon, up to 10% hafnium, up to 5% reactive metal from the group consisting of lanthanum, yttrium, and other rare earth elements, up to 5% of rare earth and/or refractory metal oxide particles, and the balance selected from the group consisting of nickel, cobalt and iron, and combinations thereof. Additions of titanium up to 5% and noble metals up to 15% are also contemplated.Type: GrantFiled: March 31, 1981Date of Patent: May 8, 1984Assignee: Howmet Turbine Components CorporationInventors: Louis E. Dardi, Srinivasan Shankar
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Patent number: 4339509Abstract: Coatings for iron-, nickel- and cobalt-base superalloys. The coatings are applied in order to provide good oxidation and/or sulfidation and thermal fatigue resistance for the substrates to which the coatings are applied. The coatings consist essentially of, by weight, 10 to 50% chromium, 3 to 15% aluminum, 0.1 to 10% manganese, up to 8% tantalum, up to 5% tungsten, up to 5% reactive metal from the group consisting of lanthanum, yttrium and other rare earth elements, up to 5 percent of rare earth and/or refractory metal oxide particles, up to 12% silicon, up to 10% hafnium, and the balance selected from the group consisting of nickel, cobalt and iron, and combinations thereof. Additions of titanium up to 5% and noble metals up to 15% are also contemplated.Type: GrantFiled: May 1, 1980Date of Patent: July 13, 1982Assignee: Howmet Turbine Components CorporationInventors: Louis E. Dardi, Srinivasan Shankar
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Patent number: 4313760Abstract: Coatings for iron-, nickel- and cobalt-base superalloys. The coatings are applied in order to provide good oxidation/sulfidation and thermal fatigue resistance for the substrates to which the coatings are applied. The coatings consist essentially of, by weight, 10 to 50% chromium, 3 to 15% aluminum, 1.0 to 15% metal mixture from the group consisting of tantalum, tungsten, manganese and combinations thereof, up to 5% reactive metal from the group consisting of lanthanum, yttrium and other rare earth elements, up to 5 percent of rare earth and/or refractory metal oxide particles, and the balance selected from the group consisting of nickel, cobalt and iron, and combinations thereof. Additions of titanium up to 5% and noble metals up to 15% are also contemplated. Tantalum makes up at least 20% of the metal mixture or 0.5% of the total coating weight, whichever is greater. Tungsten, manganese, or a combination thereof, make up at least 0.5% of the total coating.Type: GrantFiled: August 16, 1979Date of Patent: February 2, 1982Assignee: Howmet Turbine Components CorporationInventors: Louis E. Dardi, Srinivasan Shankar
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Patent number: 4212669Abstract: A method for producing precision shapes which includes the consolidation of powder metal preforms into a shaped porous preform. A first coating is applied to the preform, this first coating being porous while providing a diffusion barrier. A second coating which is also initially porous is then applied and the coated preform can then be degasified by subjecting the preform to a vacuum, particularly at elevated temperatures. The coated preform is then heated under vacuum to a temperature such that the second coating is densified to the extent that it becomes non-porous. Finally, the preform is subjected to a hot isostatic pressing operation whereby formation of high integrity, fully dense metal shape results.Type: GrantFiled: August 3, 1978Date of Patent: July 15, 1980Assignee: Howmet Turbine Components CorporationInventors: Stewart J. Veeck, William R. Freeman, Louis E. Dardi
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Patent number: 4198442Abstract: A method for the production of metal articles resistant to corrosion at elevated temperatures. The method involves the application of a first coating on an article surface, this coating comprising a cobalt, iron or nickel alloy which is compatible with the substrate and which is ductile in character. A second coating highly resistant to corrosion at elevated temperatures is applied over the first coating to form a composite coating, and an elevated temperature treatment follows to provide interfacial bonding and to minimize the detrimental effects of thermal and mechanical stresses encountered during use. The provision of a ductile first layer provides a barrier against degradation of the corrosion resistance of the outer layer and serves as a barrier against detrimental interdiffusion and crack propagation.Type: GrantFiled: October 31, 1977Date of Patent: April 15, 1980Assignee: Howmet Turbine Components CorporationInventors: Dinesh K. Gupta, Louis E. Dardi, William R. Freeman, Jr.
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Patent number: 4171562Abstract: A method for producing cast, superalloy, ferrous and titanium articles comprising the formation of a material void in the cast article, for example by utilizing a core during the casting operation or by machining a void after casting. The void is sealed relative to the surrounding atmosphere and the article is then subjected to an elevated temperature and pressure treatment in a gaseous atmosphere whereby the metal in the area of the void will yield so that the void is partially or totally eliminated. The pressure application is carried out at a temperature such that local deformation of the cast structure occurs in the region previously occupied by, and adjacent to, the void whereby a fine-grained recrystallized structure is developed in this section. Grain refined cast articles are characterized by superior low-cycle fatigue and tensile properties.Type: GrantFiled: October 7, 1977Date of Patent: October 23, 1979Assignee: Howmet Turbine Components CorporationInventors: William R. Freeman, Louis E. Dardi
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Patent number: 4145481Abstract: A process for providing coatings on metal articles whereby the articles will be resistant to corrosion at elevated temperatures. The process involves the application of an overlay on an article surface, the overlay comprising a ductile metal of a composition normally resistant to corrosion at elevated temperatures. An outer layer of aluminide or metal which is resistant to corrosion at elevated temperatures but which is subject to embrittlement at such temperatures is applied to complete the coating. Porosity in the coating is then eliminated and a high integrity corrosion resistant coating not subject to cracking is obtained by heating the article in a gaseous atmosphere to elevated temperature and simultaneously applying isostatic pressure to the article.Type: GrantFiled: August 3, 1977Date of Patent: March 20, 1979Assignee: Howmet Turbine Components CorporationInventors: Dinesh K. Gupta, Louis E. Dardi, William R. Freeman, Jr.
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Patent number: 4104782Abstract: A method for consolidating powder metal preforms and for thereby producing high performance metal shapes from powder particles. The powder particles are consolidated into a shaped porous preform, and a coating is then applied to the resulting preform. The coating is initially porous whereby the coated preform can be degasified by subjecting the preform to a vacuum, particularly at elevated temperatures. The coated preform is then heated under vacuum to a temperature such that the coating is densified to the extent that it becomes non-porous. The coated preform is then subjected to a hot isostatic pressing operation whereby formation of a high integrity, fully dense metal shape results.Type: GrantFiled: July 14, 1976Date of Patent: August 8, 1978Assignee: Howmet Turbine Components CorporationInventors: Stewart J. Veeck, William R. Freeman, Louis E. Dardi
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Patent number: 4021910Abstract: A method for treating investment cast superalloy castings wherein the portions of the castings which solidify directly against the mold walls comprise a substantially continuous or encapsulating skin of a metallic and/or nonmetallic composition. In such castings, defects in the form of material voids, including defects present immediately beneath the skin, are eliminated by the application of heat and pressure. The castings are heated to temperatures sufficient to achieve metal movement in the form of yield or creep, and a pressure of at least about 10,000 psi is applied by means of a surrounding gaseous atmosphere. The heat and pressure application deforms the material in the area of the voids and consolidates this material to substantially remove the voids and to thereby improve the performance characteristics of the castings.Type: GrantFiled: April 14, 1976Date of Patent: May 10, 1977Assignee: Howmet Turbine Components CorporationInventors: William R. Freeman, Jr., Louis E. Dardi
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Patent number: 3991928Abstract: Fiber-reinforced titanium alloy composite materials and their manufacture are disclosed. Beta-titaium alloy foils are alternated with arrays or silicon carbide coated boron fibers and consolidated at a pressure of at least 22 ksi within the temperature range of 1250.degree.-1275.degree. F.Type: GrantFiled: August 22, 1974Date of Patent: November 16, 1976Assignee: United Technologies CorporationInventors: Leonard A. Friedrich, David A. Rutz, Louis E. Dardi
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Patent number: RE31339Abstract: A process for providing coatings on metal articles whereby the articles will be resistant to corrosion at elevated temperatures. The process involves the application of an overlay on an article surface, the overlay comprising a ductile metal of a composition normally resistant to corrosion at elevated temperatures. An outer layer of aluminide or metal which is resistant to corrosion at elevated temperatures but which is subject to embrittlement at such temperatures is applied to complete the coating. Porosity in the coating is then eliminated and a high integrity corrosion resistant coating not subject to cracking is obtained by heating the article in a gaseous atmosphere to elevated temperature and simultaneously applying isostatic pressure to the article.Type: GrantFiled: September 24, 1979Date of Patent: August 9, 1983Assignee: Howmet Turbine Components CorporationInventors: Louis E. Dardi, William R. Freeman, Jr.