Laser-induced metallurgical bonding driven without contact

Abstract

A laser, aimed at a flyer plate tab, causes optical energy to be directed at the tab, specifically, at a top surface thereof. Energy impacting the tab accelerates the tab into an impact with a target sheet in a time on the order of about 10 −5 seconds. The impact occurs in excess of 100 m/s, resulting in a metallurgical bond between the tab and the target sheet. The laser preferably strikes the top surface in a normal direction, based upon an initial angularity of the tab relative to the target. The laser emission may be augmented by an ablative layer on the top surface or a transparent covering on the top surface that reacts against the expanding gas from ablative activity on the top surface. The weld is formed without physical contact between the welding device and the tab.

1 . A system for producing a metallurgical bond of a flyer plate to a target sheet, by accelerating a tab of the flyer plate into the target sheet, comprising:
 a means for positioning the flyer plate and target sheet relative to each other, such that the tab is offset from the target sheet prior to being accelerated; and   a means for inducing the acceleration of the tab into the target sheet without physical contact with the tab.   
     
     
         2 . The system of  claim 1 , wherein:
 the means for inducing the acceleration is a pulse laser.   
     
     
         3 . The system of  claim 2 , wherein:
 the pulse laser is positioned to direct an energy beam therefrom onto a top surface of the tab.   
     
     
         4 . The system of  claim 3 , wherein:
 the pulse laser is positioned to initially strike the tab in a substantially normal direction.   
     
     
         5 . The system of  claim 1 , wherein:
 the tab extends away from the target sheet at an acute angle.   
     
     
         6 . The system of  claim 1 , wherein:
 the acute angle is in the range of from about 5 to about 20 degrees.   
     
     
         7 . The system of  claim 6 , wherein:
 the acute angle and the power of the means for inducing acceleration are selected such that at least a distal end of the tab strikes the target sheet at an impact velocity of at least 100 m/s.   
     
     
         8 . The system of  claim 7 , wherein:
 the distal end is accelerated to the impact velocity in a time on the order of about 10 −5  seconds.   
     
     
         9 . The system of  claim 1 , wherein:
 the tab provides a gap between the flyer plate and the target sheet.   
     
     
         10 . The system of  claim 9 , wherein:
 the size of the gap and the power of the means for inducing acceleration are selected such that at least a distal end of the tab strikes the target plate at an impact velocity of at least 100 m/s.   
     
     
         11 . The system of  claim 10 , wherein:
 the distal end is accelerated to the impact velocity in a time on the order of about 10 −5  seconds.   
     
     
         12 . The system of  claim 1 , wherein:
 the means for inducing acceleration causes a distal end of the tab to accelerate to an impact velocity of at least 100 m/s in a time on the order of about 10 −5  seconds.