Patents by Inventor Douglas R. Barker

Douglas R. Barker 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).

  • Rapid heat treatment of nonferrous metals and alloys to obtain graded microstructures
    Patent number: 5447580
    Abstract: A method for heat treatment of nonferrous metals and alloys is described which comprises the steps of providing a billet of material comprising nonferrous metal or alloy; rapidly heating the billet to a temperature higher than the transus or solvus temperature of the material whereby a microstructure of uniform single phase grains is formed in a surface layer of preselected depth or other selected region in the billet with the starting microstructure of the material central of the billet; and cooling the billet to room temperature to preserve in the billet surface the high temperature single phase microstructure or a transformation product thereof.
    Type: Grant
    Filed: February 23, 1994
    Date of Patent: September 5, 1995
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Sheldon L. Semiatin, Douglas R. Barker
  • Billet conditioning technique for manufacturing powder metallurgy preforms
    Patent number: 4762679
    Abstract: A process for manufacturing powder metallurgy (P/M) preforms which are conditioned for optimum intrinsic workability is described which comprises steps of heating a quantity of P/M material in a can to a first preselected temperature under vacuum to degas the material, compacting the canned material at a second preselected temperature under pressure to provide a compact of the material; or cold compacting the powder to about 75% density and degassing it at suitable temperature and then vacuum hot pressing the powder at about 0.
    Type: Grant
    Filed: July 6, 1987
    Date of Patent: August 9, 1988
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Harold L. Gegel, Yellapregada V. R. K. Prasad, Sokka M. Doraivelu, Raghavan Srinivasan, J. S. Gunasekera, Douglas R. Barker, James T. Morgan, Jr., James C. Malas, Kristine A. Lark, Lawrence E. Matson
  • Optimizing hot workability and controlling microstructures in difficult to process high strength and high temperature materials
    Patent number: 4617817
    Abstract: An improved hot forming method for metals, alloys and the like, and in particular, for difficult to process high strength and high temperature metals and alloys of particular use in aerospace applications, is described, which comprises the steps of generating flow stress data as a function of strain rate and temperature on samples of the material at predetermined strain within predetermined ranges of temperature and strain rate; determining from that data the strain rate sensitivity and power dissipation efficiency of the material within the ranges of temperature and strain rate represented by the generated data; selecting values of strain rate and corresponding temperature for a selected value of the dissipation efficiency for the material; and hot forming the material at the selected strain rate and temperature values to a predetermined shape.
    Type: Grant
    Filed: February 6, 1985
    Date of Patent: October 21, 1986
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Harold L. Gegel, James C. Malas, Yellapregada V. R. K. Prasad, Sokka M. Doraivelu, Douglas R. Barker, James T. Morgan, Jr., Kristine A. Lark