Patents by Inventor Rajendra Madhukar Kelkar

Rajendra Madhukar Kelkar 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).

  • Patent number: 11865619
    Abstract: A structure is provided. The structure defines a first direction, a second direction, and a third direction, the three directions orthogonal to each other. The structure includes a first section, a second section, and a third section. The first section includes a plurality of unit cells joined together, wherein the first section has a first average tensile strength and a first average crack growth resistance. The second substantially solid section is within and surrounding each unit cell of the plurality of first section unit cells, wherein the second section has a second average tensile strength and a second average crack growth resistance, the second average tensile strength different from the first average tensile strength and the second average crack growth resistance different from the first average crack growth resistance. The third section surrounds the first section and the second section.
    Type: Grant
    Filed: July 21, 2021
    Date of Patent: January 9, 2024
    Assignee: General Electric Company
    Inventors: Evan John Dozier, Rajendra Madhukar Kelkar
  • Publication number: 20220362886
    Abstract: A method of making a component includes: depositing a metallic powder on a workplane; directing a beam from a directed energy source to fuse the powder in a pattern corresponding to a cross-sectional layer of the component; repeating in a cycle the steps of depositing and fusing to build up the component in a layer-by layer fashion; and during the cycle of depositing and melting, using an external heat control apparatus separate from the directed energy source to maintain a predetermined temperature profile of the component, such that the resulting component has a directionally-solidified or single-crystal microstructure.
    Type: Application
    Filed: August 1, 2022
    Publication date: November 17, 2022
    Inventors: Todd Jay Rockstroh, Michael Francis Xavier Gigliotti, William Thomas Carter, David Henry Abbott, Rajendra Madhukar Kelkar
  • Patent number: 11446766
    Abstract: A method of making a component includes: depositing a metallic powder on a workplane; directing a beam from a directed energy source to fuse the powder in a pattern corresponding to a cross-sectional layer of the component; repeating in a cycle the steps of depositing and fusing to build up the component in a layer-by layer fashion; and during the cycle of depositing and melting, using an external heat control apparatus separate from the directed energy source to maintain a predetermined temperature profile of the component, such that the resulting component has a directionally-solidified or single-crystal microstructure.
    Type: Grant
    Filed: February 24, 2020
    Date of Patent: September 20, 2022
    Inventors: Todd Jay Rockstroh, Michael Francis Xavier Gigliotti, William Thomas Carter, David Henry Abbott, Rajendra Madhukar Kelkar
  • Publication number: 20210346956
    Abstract: A structure is provided. The structure defines a first direction, a second direction, and a third direction, the three directions orthogonal to each other. The structure includes a first section, a second section, and a third section. The first section includes a plurality of unit cells joined together, wherein the first section has a first average tensile strength and a first average crack growth resistance. The second substantially solid section is within and surrounding each unit cell of the plurality of first section unit cells, wherein the second section has a second average tensile strength and a second average crack growth resistance, the second average tensile strength different from the first average tensile strength and the second average crack growth resistance different from the first average crack growth resistance. The third section surrounds the first section and the second section.
    Type: Application
    Filed: July 21, 2021
    Publication date: November 11, 2021
    Applicant: General Electric Company
    Inventors: Evan John Dozier, Rajendra Madhukar Kelkar
  • Patent number: 11097348
    Abstract: A structure is provided. The structure defines a first direction, a second direction, and a third direction, the three directions orthogonal to each other. The structure includes a first section, a second section, and a third section. The first section includes a plurality of unit cells joined together, wherein the first section has a first average tensile strength and a first average crack growth resistance. The second substantially solid section is within and surrounding each unit cell of the plurality of first section unit cells, wherein the second section has a second average tensile strength and a second average crack growth resistance, the second average tensile strength different from the first average tensile strength and the second average crack growth resistance different from the first average crack growth resistance. The third section surrounds the first section and the second section.
    Type: Grant
    Filed: December 8, 2017
    Date of Patent: August 24, 2021
    Assignee: General Electric Company
    Inventors: Evan John Dozier, Rajendra Madhukar Kelkar
  • Patent number: 10814395
    Abstract: An additive manufacturing machine includes a heated gas circulation system for regulating the temperature of additive powder throughout a powder bed and parts formed therein. The additive manufacturing machine includes a build platform defining a plurality of perforations and a heated gas supply that provides a flow of heated air into a distribution manifold and through the plurality of perforations and the powder bed to minimize temperature gradients within the powder bed which might otherwise result in distortion, thermal stresses, or cracking in the finished part.
    Type: Grant
    Filed: January 24, 2018
    Date of Patent: October 27, 2020
    Assignee: General Electric Company
    Inventors: David Richard Barnhart, Douglas Gerard Konitzer, Rajendra Madhukar Kelkar
  • Patent number: 10371163
    Abstract: A load absorbing system that may include a rotor blade retention system is provided. The load absorbing system may include a block, a first retainer plate, and a deformable core. The block may be selectively positioned alongside a dovetail groove. The block may have a first face directed away from the blade root and an axially-spaced second face directed toward the blade root. The first retainer plate may be attached to the second face of the block and axially positioned between the block and the axially-directed surface of the blade root. The deformable core may be positioned between the block and the first retainer plate.
    Type: Grant
    Filed: February 2, 2016
    Date of Patent: August 6, 2019
    Assignee: General Electric Company
    Inventors: Michael Jason Bishop, Rajendra Madhukar Kelkar, Alex Yuen, Andrew Philip Woodfield
  • Publication number: 20190224749
    Abstract: An additive manufacturing machine includes a heated gas circulation system for regulating the temperature of additive powder throughout a powder bed and parts formed therein. The additive manufacturing machine includes a build platform defining a plurality of perforations and a heated gas supply that provides a flow of heated air into a distribution manifold and through the plurality of perforations and the powder bed to minimize temperature gradients within the powder bed which might otherwise result in distortion, thermal stresses, or cracking in the finished part.
    Type: Application
    Filed: January 24, 2018
    Publication date: July 25, 2019
    Inventors: David Richard Barnhart, Douglas Gerard Konitzer, Rajendra Madhukar Kelkar
  • Publication number: 20190176232
    Abstract: A structure is provided. The structure defines a first direction, a second direction, and a third direction, the three directions orthogonal to each other. The structure includes a first section, a second section, and a third section. The first section includes a plurality of unit cells joined together, wherein the first section has a first average tensile strength and a first average crack growth resistance. The second substantially solid section is within and surrounding each unit cell of the plurality of first section unit cells, wherein the second section has a second average tensile strength and a second average crack growth resistance, the second average tensile strength different from the first average tensile strength and the second average crack growth resistance different from the first average crack growth resistance. The third section surrounds the first section and the second section.
    Type: Application
    Filed: December 8, 2017
    Publication date: June 13, 2019
    Inventors: Evan John Dozier, Rajendra Madhukar Kelkar
  • Publication number: 20190061005
    Abstract: Methods for forming a high-quality powder from a feedstock powder of feedstock particles having irregular shapes are provided. The method includes exposing the feedstock powder to a plasma field to form a treated powder of treated particles having a more spherical shape than the feedstock particles. Prior to the plasma field exposure, the feedstock particles have an oxidized layer thereon as a result from previous exposure to water. After exposure to the plasma field, the treated particles are substantially free from an oxidized layer.
    Type: Application
    Filed: April 25, 2018
    Publication date: February 28, 2019
    Inventor: Rajendra Madhukar Kelkar
  • Publication number: 20180071820
    Abstract: A method of binder jet printing a metal part includes depositing a layer of a metal powder on a working surface of a binder jet printer and selectively printing a binder solution having a reversible binder into the layer of metal powder in a pattern to generate a printed layer. The pattern is representative of a structure of a layer of the metal part. The method also includes curing the reversible binder in the printed layer to generate a layer of a green body metal part and heating the green body metal part above a first temperature to remove a substantial portion of the reversible binder and generate a brown body metal part. The reversible binder is thermally decomposed to generate oligomers that remain within and strengthen the brown body metal part. The method further includes heating the brown body metal part above a second temperature to remove the oligomers and sinter the metal powder to generate the metal part. The metal part is substantially free of char residue.
    Type: Application
    Filed: September 9, 2016
    Publication date: March 15, 2018
    Inventors: Arunkumar Natarajan, Rajendra Madhukar Kelkar, Jeffrey Jon Schoonover, Prabhjot Singh, Venkat Subramaniam Venkataramani, Kwok Pong Chan, John Leman
  • Publication number: 20180009032
    Abstract: Methods of making metal objects are provided. These methods generally involve adding a metal powder slurry into a sacrificial mold, such as a mold made by three dimensional printing, and heating the slurry/mold mixture. The heating steps may include curing the slurry to make a green part inside the mold, debinding to burn off the mold and binder to make a brown part, sintering, and hot isostatic pressing. Metal products, such as aircraft engine parts, are also provided.
    Type: Application
    Filed: July 8, 2016
    Publication date: January 11, 2018
    Inventors: Rajendra Madhukar KELKAR, Pong Kwok CHAN, Singh PRABHJOT, Michael John MCCARREN, Arunkumar NATARAJAN, John T. LEMAN
  • Publication number: 20170218973
    Abstract: A load absorbing system that may include a rotor blade retention system is provided. The load absorbing system may include a block, a first retainer plate, and a deformable core. The block may be selectively positioned alongside a dovetail groove. The block may have a first face directed away from the blade root and an axially-spaced second face directed toward the blade root. The first retainer plate may be attached to the second face of the block and axially positioned between the block and the axially-directed surface of the blade root. The deformable core may be positioned between the block and the first retainer plate.
    Type: Application
    Filed: February 2, 2016
    Publication date: August 3, 2017
    Inventors: Michael Jason Bishop, Rajendra Madhukar Kelkar, Alex Yuen, Andrew Philip Woodfield
  • Publication number: 20120040183
    Abstract: Cemented carbide compositions consisting essentially of tungsten carbide particles and a cobalt-silicon alloy binder are disclosed. Also disclosed are methods of making the cemented carbide compositions and articles which incorporate the cemented carbide compositions. Pellets having the cemented carbide compositions may be used in the uncrushed or crushed form. The cemented carbide compositions may also be used as metal cutting tool inserts, road construction tool inserts, oil or gas drill inserts, mining tool inserts, and as substrates for ultrahard materials, such as PCD, PCBN, and TSP.
    Type: Application
    Filed: August 11, 2010
    Publication date: February 16, 2012
    Applicant: KENNAMETAL, INC.
    Inventor: Rajendra Madhukar Kelkar