Patents by Inventor Dhruba J. Chakrabarti

Dhruba J. Chakrabarti 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).

  • Publication number: 20220333229
    Abstract: Described herein are novel 7xxx series aluminum alloys. The alloys exhibit high strength. The alloys can be used in a variety of applications, including automotive, transportation, electronics, aerospace, and industrial applications. Also described herein are methods of making and processing the alloys. Further described herein are methods of producing a metal sheet, which include casting an aluminum alloy as described herein to form an ingot, homogenizing the ingot, hot rolling the ingot to produce a hot band, and cold rolling the hot band to a metal sheet of final gauge.
    Type: Application
    Filed: July 1, 2022
    Publication date: October 20, 2022
    Applicant: Novelis Inc.
    Inventors: RAJEEV G. KAMAT, DHRUBA J. CHAKRABARTI, RASHMI RASHMI MOHANTY, RAHUL VILAS KULKARNI, DUANE E. BENDZINSKI, JUERGEN TIMM
  • Patent number: 11421309
    Abstract: Described herein are novel 7xxx series aluminum alloys. The alloys exhibit high strength. The alloys can be used in a variety of applications, including automotive, transportation, electronics, aerospace, and industrial applications. Also described herein are methods of making and processing the alloys. Further described herein are methods of producing a metal sheet, which include casting an aluminum alloy as described herein to form an ingot, homogenizing the ingot, hot rolling the ingot to produce a hot band, and cold rolling the hot band to a metal sheet of final gauge.
    Type: Grant
    Filed: October 28, 2016
    Date of Patent: August 23, 2022
    Assignee: Novelis Inc.
    Inventors: Rajeev G. Kamat, Dhruba J. Chakrabarti, Rashmi Ranjan Mohanty, Rahul Vilas Kulkarni, Duane E. Bendzinski, Juergen Timm
  • Patent number: 10450640
    Abstract: Aluminum alloy products, such as plate, forgings and extrusions, suitable for use in making aerospace structural components like integral wing spars, ribs and webs, comprises about: 6 to 10 wt. % Zn; 1.2 to 1.9 wt. % Mg; 1.2 to 2.2 wt. % Cu, with Mg?(Cu+0.3); and 0.05 to 0.4 wt. % Zr, the balance Al, incidental elements and impurities. Preferably, the alloy contains about 6.9 to 8.5 wt. % Zn; 1.2 to 1.7 wt. % Mg; 1.3 to 2 wt. % Cu. This alloy provides improved combinations of strength and fracture toughness in thick gauges. When artificially aged per the 3-stage method of preferred embodiments, this alloy also achieves superior SCC performance, including under seacoast conditions.
    Type: Grant
    Filed: August 8, 2013
    Date of Patent: October 22, 2019
    Assignee: ARCONIC INC.
    Inventors: Dhruba J. Chakrabarti, John Liu, Jay H. Goodman, Gregory B. Venema, Ralph R. Sawtell, Cynthia M. Krist, Robert W. Westerlund
  • Publication number: 20170121802
    Abstract: Described herein are novel 7xxx series aluminum alloys. The alloys exhibit high strength. The alloys can be used in a variety of applications, including automotive, transportation, electronics, aerospace, and industrial applications. Also described herein are methods of making and processing the alloys. Further described herein are methods of producing a metal sheet, which include casting an aluminum alloy as described herein to form an ingot, homogenizing the ingot, hot rolling the ingot to produce a hot band, and cold rolling the hot band to a metal sheet of final gauge.
    Type: Application
    Filed: October 28, 2016
    Publication date: May 4, 2017
    Applicant: Novelis Inc.
    Inventors: RAJEEV G. KAMAT, DHRUBA J. CHAKRABARTI, RASHMI RANJAN MOHANTY, RAHUL VILAS KULKARNI, DUANE E. BENDZINSKI, JUERGEN TIMM
  • Publication number: 20150368773
    Abstract: Aluminum alloy products about 4 inches thick or less that possesses the ability to achieve, when solution heat treated, quenched, and artificially aged, and in parts made from the products, an improved combination of strength, fracture toughness and corrosion resistance, the alloy consisting essentially of: about 6.8 to about 8.5 wt. % Zn, about 1.5 to about 2.00 wt. % Mg, about 1.75 to about 2.3 wt. % Cu; about 0.05 to about 0.3 wt. % Zr, less than about 0.1 wt. % Mn, less than about 0.05 wt. % Cr, the balance Al, incidental elements and impurities and a method for making same. The instantly disclosed alloys are useful in making structural members for commercial airplanes including, but not limited to, upper wing skins and stringers, spar caps, spar webs and ribs of either built-up or integral construction.
    Type: Application
    Filed: January 28, 2015
    Publication date: December 24, 2015
    Inventors: Gary H. Bray, Dhruba J. Chakrabarti, Diana K. Denzer, Jen C. Lin, John Newman, Gregory B. Venema, Cagatay Yanar, Julien Boselli
  • Patent number: 8961715
    Abstract: Aluminum alloy products about 4 inches thick or less that possesses the ability to achieve, when solution heat treated, quenched, and artificially aged, and in parts made from the products, an improved combination of strength, fracture toughness and corrosion resistance, the alloy consisting essentially of: about 6.8 to about 8.5 wt. % Zn, about 1.5 to about 2.00 wt. % Mg, about 1.75 to about 2.3 wt. % Cu; about 0.05 to about 0.3 wt. % Zr, less than about 0.1 wt. % Mn, less than about 0.05 wt. % Cr, the balance Al, incidental elements and impurities and a method for making same. The instantly disclosed alloys are useful in making structural members for commercial airplanes including, but not limited to, upper wing skins and stringers, spar caps, spar webs and ribs of either built-up or integral construction.
    Type: Grant
    Filed: April 17, 2014
    Date of Patent: February 24, 2015
    Assignee: Alcoa Inc.
    Inventors: Gary H. Bray, Dhruba J. Chakrabarti, Diana K. Denzer, Jen C. Lin, John Newman, Gregory B. Venema, Cagatay Yanar, Julien Boselli
  • Patent number: 8840737
    Abstract: Aluminum alloy products about 4 inches thick or less that possesses the ability to achieve, when solution heat treated, quenched, and artificially aged, and in parts made from the products, an improved combination of strength, fracture toughness and corrosion resistance, the alloy consisting essentially of: about 6.8 to about 8.5 wt. % Zn, about 1.5 to about 2.00 wt. % Mg, about 1.75 to about 2.3 wt. % Cu; about 0.05 to about 0.3 wt. % Zr, less than about 0.1 wt. % Mn, less than about 0.05 wt. % Cr, the balance Al, incidental elements and impurities and a method for making same. The instantly disclosed alloys are useful in making structural members for commercial airplanes including, but not limited to, upper wing skins and stringers, spar caps, spar webs and ribs of either built-up or integral construction.
    Type: Grant
    Filed: May 14, 2008
    Date of Patent: September 23, 2014
    Assignee: Alcoa Inc.
    Inventors: Gary H. Bray, Dhruba J. Chakrabarti, Diana K. Denzer, Jen C. Lin, John Newman, Gregory B. Venema, Cagatay Yanar, Julien Boselli
  • Publication number: 20140227131
    Abstract: Aluminum alloy products about 4 inches thick or less that possesses the ability to achieve, when solution heat treated, quenched, and artificially aged, and in parts made from the products, an improved combination of strength, fracture toughness and corrosion resistance, the alloy consisting essentially of: about 6.8 to about 8.5 wt. % Zn, about 1.5 to about 2.00 wt. % Mg, about 1.75 to about 2.3 wt. % Cu; about 0.05 to about 0.3 wt. % Zr, less than about 0.1 wt. % Mn, less than about 0.05 wt. % Cr, the balance Al, incidental elements and impurities and a method for making same. The instantly disclosed alloys are useful in making structural members for commercial airplanes including, but not limited to, upper wing skins and stringers, spar caps, spar webs and ribs of either built-up or integral construction.
    Type: Application
    Filed: April 17, 2014
    Publication date: August 14, 2014
    Applicant: ALCOA INC.
    Inventors: Gary H. Bray, Dhruba J. Chakrabarti, Diana K. Denzer, Jen C. Lin, John Newman, Gregory B. Venema, Cagatay Yanar, Julien Boselli
  • Publication number: 20130312877
    Abstract: Aluminum alloy products, such as plate, forgings and extrusions, suitable for use in making aerospace structural components like integral wing spars, ribs and webs, comprises about: 6 to 10 wt. % Zn; 1.2 to 1.9 wt. % Mg; 1.2 to 2.2 wt. % Cu, with Mg?(Cu+0.3); and 0.05 to 0.4 wt. % Zr, the balance Al, incidental elements and impurities. Preferably, the alloy contains about 6.9 to 8.5 wt. % Zn; 1.2 to 1.7 wt. % Mg; 1.3 to 2 wt. % Cu. This alloy provides improved combinations of strength and fracture toughness in thick gauges. When artificially aged per the 3-stage method of preferred embodiments, this alloy also achieves superior SCC performance, including under seacoast conditions.
    Type: Application
    Filed: August 8, 2013
    Publication date: November 28, 2013
    Applicant: ALCOA INC.
    Inventors: Dhruba J. Chakrabarti, John Liu, Jay H. Goodman, Gregory B. Venema, Ralph R. Sawtell, Cynthia M. Krist, Robert W. Westerlund
  • Patent number: 8524014
    Abstract: Aluminum alloy products, such as plate, forgings and extrusions, suitable for use in making aerospace structural components like integral wing spars, ribs and webs, comprises about: 6 to 10 wt. % Zn; 1.2 to 1.9 wt. % Mg; 1.2 to 2.2 wt. % Cu, with Mg?(Cu+0.3); and 0.05 to 0.4 wt. % Zr, the balance Al, incidental elements and impurities. Preferably, the alloy contains about 6.9 to 8.5 wt. % Zn; 1.2 to 1.7 wt. % Mg; 1.3 to 2 wt. % Cu. This alloy provides improved combinations of strength and fracture toughness in thick gauges. When artificially aged per the 3-stage method of preferred embodiments, this alloy also achieves superior SCC performance, including under seacoast conditions.
    Type: Grant
    Filed: July 7, 2011
    Date of Patent: September 3, 2013
    Assignee: Alcoa Inc.
    Inventors: Dhruba J. Chakrabarti, John Liu, Jay H. Goodman, Gregory B. Venema, Ralph R. Sawtell, Cynthia M. Krist, Robert W. Westerlund
  • Patent number: 8083870
    Abstract: Aluminum alloy products, such as plate, forgings and extrusions, suitable for use in making aerospace structural components like integral wing spars, ribs and webs, comprises about: 6 to 10 wt. % Zn; 1.2 to 1.9 wt. % Mg; 1.2 to 2.2 wt. % Cu, with Mg?(Cu+0.3); and 0.05 to 0.4 wt. % Zr, the balance Al, incidental elements and impurities. Preferably, the alloy contains about 6.9 to 8.5 wt. % Zn; 1.2 to 1.7 wt. % Mg; 1.3 to 2 wt. % Cu. This alloy provides improved combinations of strength and fracture toughness in thick gauges. When artificially aged per the three stage method of preferred embodiments, this alloy also achieves superior SCC performance, including under seacoast conditions.
    Type: Grant
    Filed: February 7, 2005
    Date of Patent: December 27, 2011
    Assignee: Alcoa Inc.
    Inventors: Dhruba J. Chakrabarti, John Liu, Jay H. Goodman, Gregory B. Venema, Ralph R. Sawtell, Cynthia M. Krist, Robert W. Westerlund
  • Publication number: 20110268603
    Abstract: Aluminum alloy products, such as plate, forgings and extrusions, suitable for use in making aerospace structural components like integral wing spars, ribs and webs, comprises about: 6 to 10 wt. % Zn; 1.2 to 1.9 wt. % Mg; 1.2 to 2.2 wt. % Cu, with Mg?(Cu+0.3); and 0.05 to 0.4 wt. % Zr, the balance Al, incidental elements and impurities. Preferably, the alloy contains about 6.9 to 8.5 wt. % Zn; 1.2 to 1.7 wt. % Mg; 1.3 to 2 wt. % Cu. This alloy provides improved combinations of strength and fracture toughness in thick gauges. When artificially aged per the 3-stage method of preferred embodiments, this alloy also achieves superior SCC performance, including under seacoast conditions.
    Type: Application
    Filed: July 7, 2011
    Publication date: November 3, 2011
    Applicant: Alcoa Inc.
    Inventors: Dhruba J. Chakrabarti, John Liu, Jay H. Goodman, Gregory B. Venema, Ralph R. Sawtell, Cynthia M. Krist, Robert W. Westerlund
  • Patent number: 7678205
    Abstract: Aluminum alloy products, such as plate, forgings and extrusions, suitable for use in making aerospace structural components like integral wing spars, ribs and webs, comprises about: 6 to 10 wt. % Zn; 1.2 to 1.9 wt. % Mg; 1.2 to 2.2 wt. % Cu, with Mg?(Cu+0.3); and 0.05 to 0.4 wt. % Zr, the balance Al, incidental elements and impurities. Preferably, the alloy contains about 6.9 to 8.5 wt. % Zn; 1.2 to 1.7 wt. % Mg; 1.3 to 2 wt. % Cu. This alloy provides improved combinations of strength and fracture toughness in thick gauges. When artificially aged per the three stage method of preferred embodiments, this alloy also achieves superior SCC performance, including under seacoast conditions.
    Type: Grant
    Filed: November 28, 2005
    Date of Patent: March 16, 2010
    Assignee: Alcoa Inc.
    Inventors: Dhruba J. Chakrabarti, John Liu, Jay H. Goodman, Gregory B. Venema, Ralph R. Sawtell, Cynthia M. Krist, Robert W. Westerlund
  • Publication number: 20100037998
    Abstract: Aluminum alloy products about 4 inches thick or less that possesses the ability to achieve, when solution heat treated, quenched, and artificially aged, and in parts made from the products, an improved combination of strength, fracture toughness and corrosion resistance, the alloy consisting essentially of: about 6.8 to about 8.5 wt. % Zn, about 1.5 to about 2.00 wt. % Mg, about 1.75 to about 2.3 wt. % Cu; about 0.05 to about 0.3 wt. % Zr, less than about 0.1 wt. % Mn, less than about 0.05 wt. % Cr, the balance Al, incidental elements and impurities and a method for making same. The instantly disclosed alloys are useful in making structural members for commercial airplanes including, but not limited to, upper wing skins and stringers, spar caps, spar webs and ribs of either built-up or integral construction.
    Type: Application
    Filed: May 14, 2008
    Publication date: February 18, 2010
    Applicant: Alcoa Inc.
    Inventors: Gary H. Bray, Dhruba J. Chakrabarti, Diana K. Denzer, Jen C. Lin, John Newman, Gregory B. Venema, Cagatay Yanar, Julien Boselli
  • Publication number: 20080283163
    Abstract: Aluminum alloy products about 4 inches thick or less that possesses the ability to achieve, when solution heat treated, quenched, and artificially aged, and in parts made from the products, an improved combination of strength, fracture toughness and corrosion resistance, the alloy consisting essentially of: about 6.8 to about 8.5 wt. % Zn, about 1.5 to about 2.00 wt. % Mg, about 1.75 to about 2.3 wt. % Cu; about 0.05 to about 0.3 wt. % Zr, less than about 0.1 wt. % Mn, less than about 0.05 wt. % Cr, the balance Al, incidental elements and impurities and a method for making same. The invention alloy is useful in making structural members for commercial airplanes including, but not limited to, upper wing skins and stringers, spar caps, spar webs and ribs of either built-up or integral construction. The invention alloy may be aged by 2 or 3 step practices while exceeding the SCC requirements for applications for which the invention alloy is primarily intended.
    Type: Application
    Filed: May 14, 2007
    Publication date: November 20, 2008
    Inventors: Gary H. Bray, Dhruba J. Chakrabarti, Diana Denzer, Jen Lin, John Newman, Greg Venema, Cagatay Yanar
  • Patent number: 7018489
    Abstract: A method of artificially aging an aluminum alloy product to achieve a property in the product having the steps of aging the product to achieve the property by heating the product over an aging period, the aging period including a time period where the product is in an underaged state, and terminating the heating when the property is achieved according to a mathematical formula. The property is calculated as a function of time and product temperature measured over the aging period. Calculation of the property includes integration of the thermal effects on the product over the entire aging period including during the time period of underaged product state.
    Type: Grant
    Filed: November 13, 2002
    Date of Patent: March 28, 2006
    Assignee: Alcoa Inc.
    Inventors: William D. Bennon, Vivek M. Sample, Dhruba J. Chakrabarti
  • Patent number: 6972110
    Abstract: Aluminum alloy products, such as plate, forgings and extrusions, suitable for use in making aerospace structural components like integral wing spars, ribs and webs, comprises about: 6 to 10 wt. % Zn; 1.2 to 1.9 wt. % Mg; 1.2 to 2.2 wt. % Cu, with Mg?(Cu+0.3); and 0.05 to 0.4 wt. % Zr, the balance Al, incidental elements and impurities. Preferably, the alloy contains about 6.9 to 8.5 wt. % Zn; 1.2 to 1.7 wt. % Mg; 1.3 to 2 wt. % Cu. This alloy provides improved combinations of strength and fracture toughness in thick gauges. When artificially aged per the three stage method of preferred embodiments, this alloy also achieves superior SCC performance, including under seacoast conditions.
    Type: Grant
    Filed: October 4, 2001
    Date of Patent: December 6, 2005
    Assignee: Alcoa Inc.
    Inventors: Dhruba J. Chakrabarti, John Liu, Jay H. Goodman, Gregory B. Venema, Ralph R. Sawtell, Cynthia M. Krist, Robert W. Westerlund
  • Patent number: 6911099
    Abstract: A process for improving 6XXX alloys, such as 6013, preferably includes heating, hot rolling, inter-rolling thermal treatment at a very high temperature such as 1020° F. or more, again hot rolling (with or without subsequent continuous hot rolling or cold rolling or both), solution heat treating and artificial aging. The initial heating, inter-rolling, thermal treatment and solution treatment, especially the latter two, are carried out at very high temperatures such as 1030° F. Each aforesaid hot rolling stage produces substantial metal thickness reduction. The improved sheet or plate product has a substantially reduced occurrence of reduced density features revealed in scanning electron microscope examination at 500X and exhibits improved (reduced) fatigue crack growth rate providing an advantage in aerospace applications such as fuselage skin, especially fuselage belly skin.
    Type: Grant
    Filed: October 29, 2002
    Date of Patent: June 28, 2005
    Assignee: Alcoa Inc.
    Inventors: Paul E. Magnusen, Dhruba J. Chakrabarti, Anne E. Zemo, Robert W. Westerlund, Anthony Morales, Daniel T. Moulton
  • Publication number: 20040089381
    Abstract: A method of artificially aging an aluminum alloy product to achieve a property in the product having the steps of aging the product to achieve the property by heating the product over an aging period, the aging period including a time period where the product is in an underaged state, and terminating the heating when the property is achieved according to a mathematical formula. The property is calculated as a function of time and product temperature measured over the aging period. Calculation of the property includes integration of the thermal effects on the product over the entire aging period including during the time period of underaged product state.
    Type: Application
    Filed: November 13, 2002
    Publication date: May 13, 2004
    Inventors: William D. Bennon, Vivek M. Sample, Dhruba J. Chakrabarti
  • Patent number: 6613167
    Abstract: A process for improving 6XXX alloys, such as 6013, preferably includes heating, hot rolling, inter-rolling thermal treatment at a very high temperature such as 1020° F. or more, again hot rolling (with or without subsequent continuous hot rolling or cold rolling or both), solution heat treating and artificial aging. The initial heating, inter-rolling, thermal treatment and solution treatment, especially the latter two, are carried out at very high temperatures such as 1030° F. Each aforesaid hot rolling stage produces substantial metal thickness reduction. The improved sheet or plate product has a substantially reduced occurrence of reduced density features revealed in scanning electron microscope examination at 500× and exhibits improved (reduced) fatigue crack growth rate providing an advantage in aerospace applications such as fuselage skin, especially fuselage belly skin.
    Type: Grant
    Filed: June 1, 2001
    Date of Patent: September 2, 2003
    Assignee: Alcoa Inc.
    Inventors: Paul E. Magnusen, Dhruba J. Chakrabarti, Anne E. Zemo, Robert W. Westerlund, Anthony Morales, Daniel T. Moulton