Optimization of melt pool shape in a joining process

Abstract

There is provided a process for welding that includes applying a first amount of energy 118 and a second amount of energy 122 to a substrate 105 effective to provide a melt pool 100 comprising a curvilinear and/or curviplanar solid/liquid interface 103 about at least a trailing edge region 106 and within a depth (D) of the melt pool 100.

1 . A process for welding comprising:
 forming a melt pool having a width along a longitudinal length of a substrate;   heating the substrate outside the width of the melt pool with an amount of energy which does not melt the substrate but is effective to reduce a resolidification rate of the melt pool and reduce segregation of artifacts and stress concentration along a centerline of the width.   
     
     
         2 . The process of  claim 1 , wherein the forming is done with a first amount of energy from a first energy source, and wherein the heating is done with a second amount of energy from a distinct second energy source or time-shared energy from the first energy source. 
     
     
         3 . The process of  claim 1 , wherein the heating is done on both opposed sides of the width of the melt pool. 
     
     
         4 . The process of  claim 1 , wherein the heating is done following the initiation of the forming of the melt pool and behind a leading edge of the forming melt pool. 
     
     
         5 . The process of  claim 1 , wherein the forming is done in a direction of the weld, and wherein the heating is done in a direction transverse to the direction of the weld. 
     
     
         6 . The process of  claim 1 , wherein the forming forms a keyhole in the melt pool, and wherein the heating is done by applying heat outside the width of the melt pool behind the keyhole. 
     
     
         7 . The process of  claim 1 , wherein the heating and forming are done simultaneously via a two-in-one fiber, wherein the forming is done through a central portion of the fiber, and wherein the heating is done through an annular region about the central portion. 
     
     
         8 . The process of  claim 1 , wherein the forming and the heating are done using a laser source, and wherein the heating of the melt pool results in a melt pool having substantially a bowl shape. 
     
     
         9 . The process of  claim 1 , further comprising applying additional energy to the melt pool at a location remote from the centerline of the width, the additional energy further effective to decrease a solidification rate of the melt pool at edges of the melt pool. 
     
     
         10 . A process for welding comprising:
 forming a melt pool in a substrate via applying a first amount of energy thereto; and   applying a second amount of energy to the substrate outside a periphery of the melt pool to reduce segregation of artifacts and stress concentration along a centerline of a width of the melt pool.   
     
     
         11 . The process of  claim 10 , wherein the forming of the melt pool is done with a first amount of energy from a first energy source, and wherein the applying of a second amount of energy outside a periphery of the melt pool is done with a second amount of energy from a distinct second energy source or time-shared energy from the first energy source. 
     
     
         12 . The process of  claim 10 , wherein the applying of a second amount of energy outside a periphery of the melt pool is done following initiation of the forming of the melt pool behind a leading edge of the forming melt pool. 
     
     
         13 . The process of  claim 10 , wherein the forming of the melt pool is done in a direction of the weld, and wherein the applying of a second amount of energy outside a periphery of the melt pool is done in a direction transverse to the direction of the weld. 
     
     
         14 . The process of  claim 10 , wherein the forming a melt pool forms a keyhole in the melt pool, and wherein the applying of a second amount of energy outside a periphery of the melt pool is done by applying energy to the substrate outside the width of the melt pool behind the keyhole. 
     
     
         15 . The process of  claim 10 , wherein the forming and applying are done simultaneously via a two-in-one fiber, wherein the melt pool is formed through energy traveling through a central portion of the fiber, and wherein the applying of a second amount of energy outside a periphery of the melt is done through an annular region about the central portion. 
     
     
         16 . The process of  claim 10 , wherein the forming and the applying are done using a laser source, and wherein the heating of the melt pool results in a melt pool having substantially a bowl shape. 
     
     
         17 . The process of  claim 10 , further comprising applying additional energy to the melt pool at a location remote from the centerline of the width, the additional energy further effective to decrease a solidification rate of the melt pool at edges of the melt pool. 
     
     
         18 . A process for welding comprising applying a first amount of energy and a second amount of energy to the substrate effective to provide a melt pool comprising a curvilinear and a curviplanar solid/liquid interface about at least a trailing edge region and within a depth of the melt pool, the applying of the first and second energies effective to reduce turbulence of the melt pool; and reduce segregation of artifacts and stress concentration within the depth and along a centerline of a width of the melt pool. 
     
     
         19 . The process of  claim 18 , wherein the applying comprises:
 applying the first amount of energy to the substrate and the second amount of energy behind the first amount of energy in a direction of the weld to provide the melt pool, wherein the second amount of energy is applied to a greater extent than the first amount of energy.   
     
     
         20 . The process of  claim 18 , wherein the applying comprises:
 forming a melt pool having a width along a longitudinal length of the substrate;   heating the substrate outside the width of the melt pool with an amount of energy which does not melt the substrate but is effective to reduce a resolidification rate of the melt pool and reduce segregation of artifacts and stress concentration along the centerline of the width.