Methods And Apparatus For Stress Relief Using Multiple Energy Sources

Abstract

Methods are presented for modifying a physical property of a structure, such as reducing or relieving remaining internal stress, in which two or more energy types are concurrently applied to the structure to change the physical property of interest in an accelerated fashion. A first energy type, such as heat, is applied according to time values and operational settings derived from a first order rate relationship for the first energy type and from a first order rate relationship for a second energy type. The second energy type, such as vibration or other time-varying energy form, is applied concurrently for the time value. Methods are also provided for determining operational settings for concurrent application of multiple energy types to a structure.

1 - 32 . (canceled) 
     
     
         33 . A method for changing a physical property of a metal or metallic alloy manufactured part, comprising:
 performing a first energy process by providing a first energy to the manufactured part, according to a first operational setting;   performing a second energy process by providing a second energy to the manufactured part, according to a second operational setting;   wherein the first and second energy processes are performed concurrently to provide energy above an activation energy for the material of the manufactured part; and   wherein at least one of the first or second operational settings and the time value are selected according to a desired value of the physical property and according to a first order rate relationship that relates concurrent application of the first and second energy to the manufactured part and the physical property of the manufactured part,   whereby a temporal acceleration of the change in the desired value of the physical property occurs.   
     
     
         34 . The method of  claim 33 , wherein the first energy is a heat energy that is provided to the manufactured part at or below a temperature to avoid melting the manufactured part. 
     
     
         35 . The method of  claim 33 , wherein the second energy is oscillatory. 
     
     
         36 . The method of  claim 33 , wherein the second energy is selected from the group consisting of sonic, laser, electrical, magnetic, mechanical, and microwave. 
     
     
         37 . The method of  claim 33 , wherein the physical property is one of creep rate, creep, strength, corrosion susceptibility, fatigue life, residual stress, internal stress, aging, or dislocation mobility, and the desired value of the physical property is associated with the physical property. 
     
     
         38 . The method of  claim 33 , wherein the first order rate relationship is determined by curves, or mathematical expressions resulting from curve-fitting a series of data points. 
     
     
         39 . A method for reducing internal stress of a structure comprising:
 determining a first order rate relationship for a first energy process which relates internal stress of the structure to a first order rate parameter of the first energy process;   determining a first order rate relationship for a second energy process different than the first energy process which relates internal stress of the structure to a first order rate parameter of the second energy process;   correlating the first order rate relationships of the first and second energy processes to determine a time value for concurrent application of the first and second energies; and   concurrently applying the first energy process and the second energy process to the structure for the time value.   
     
     
         40 . The method as set forth in  claim 39  wherein the first order rate parameter for the first energy process is a first Larson Miller parameter P 1  and the second order rate parameter for the second energy process is a second Larson Miller parameter P 2 . 
     
     
         41 . The method as set forth in  claim 39  wherein the first energy process is thermal and the second energy process is oscillatory. 
     
     
         42 . The method as set forth in  claim 39  wherein the first energy process is thermal and the second energy process is magnetic.