Method for high pressure/high velocity welding or joining first and second metal workpieces before welding/joining; article of manufacture made thereby

Abstract

A method is provided for forming a metallurgical bond. A first metal workpiece and one or more second metal workpieces are brought into proximity to one another such that a first portion of the first workpiece is in general overlying relationship with a second portion of the one or more second workpieces. A suitable material is provided between said first portion and said second portion, said material being in the form of particles or foil. At least a first part of said first workpiece comprising said first portion is forced toward said a part of the one or more second workpiece comprising said second portion by means of any one of a suitable high pressure joining process and a high speed joining process, such as to cause the said first metal workpiece and said one or more second metal workpieces to become joined or welded to one another to form a metallurgical bond therebetween.

1 - 31 . (canceled) 
     
     
         32 . A method for forming a metallurgical bond between a first metal workpiece and one or more second metal workpieces, comprising:
 (a) bringing said first metal workpiece and said one or more second metal workpieces into proximity to one another such that a first portion of said first workpiece is in general overlying relationship with a second portion of said one or more second workpieces;   (b) providing suitable material between said first portion and said second portion, said material being in the form of particles or foil ; and   (c) forcing at least a first part of said first workpiece comprising said first portion toward said a part of said one or more second workpiece comprising said second portion by means of any one of a suitable high pressure joining process and a high speed joining process, such as to cause the said first metal workpiece and said one or more second metal workpieces to become joined or welded to one another to form a metallurgical bond therebetween.   
     
     
         33 . Method according to  claim 32 , wherein said any one of a suitable high pressure joining process and a high speed joining process comprises forcing said first portion and said second portion into a metallurgical bond-forming mutual contact in a manner such as to induce a contact front between said first portion and said second portion with said material therebetween, said contact front defining a locus between at least one metallurgically-bonded portion, wherein facing parts of said first portion and said second portion have been joined by said process, and at least one unbonded portion, wherein facing parts of said first portion and said second portion are to be joined by said process, wherein said contact front rapidly propagates between said first portion and said second portion. 
     
     
         34 . Method according to  claim 33 , wherein at said contact front, said first portion and said second portion meet at said contact front at a predetermined acute angle. 
     
     
         35 . Method according to  claim 33 , wherein said contact front propagates at a velocity above about 3*10 3  m/second. 
     
     
         36 . Method according to  claim 33 , wherein said contact front propagates at a velocity above about 600 m/second. 
     
     
         37 . A method according to  claim 33 , wherein said contact front propagates at a velocity sufficient to form a plasma between said facing parts of said first portion and said second portion in said unbonded portion. 
     
     
         38 . Method according to  claim 33 , wherein said process is a magnetic pulse forming (PMF) process. 
     
     
         39 . Method according to  claim 38 , wherein in step (c) said PMF process comprises inducing a pulse magnetic force by passing an electric current pulse through a coil, the force being such as to cause said first part to impact onto said second part with an initial kinetic energy of the first workpiece prior to impact which is equal to or larger than the combined plastic deformation energy of the first workpiece and the elastic deformation energy of the second workpiece after impact, whereby said one or more second metal workpieces to become joined or welded to one another. 
     
     
         40 . Method according to  claim 33 , wherein said process is any one of an explosive welding process, a friction welding process, an ultrasonic welding process, a diffusion welding process, a cold welding process, a pressure gas welding process, and a forge welding process. 
     
     
         41 . Method according to  claim 32 , wherein in step (b) said particles are applied to at least one of said first portion and said second portion. 
     
     
         42 . Method according to  claim 41 , wherein step (b) is performed prior to step (a). 
     
     
         43 . Method according to  claim 41 , wherein said particles are applied to at least one of a first surface of said first portion and a second surface of said second portion. 
     
     
         44 . Method according to  claim 43 , wherein said particles are applied to at least one of a first surface and said second surface by one of :
 spraying or coating said to at least one of a first surface said second surface with an emulsion comprising said metallic powder;   inducing static electrical attraction forces between at least one of a first surface said second surface and said particles;   wherein said particles are metallic and are magnetized and at least one of said first portion and said second portion is magnetisable and suitable current is passed therethrough to magnetise the same in proximity to said metallic powder, causing the powder to be magnetically attracted to at least one of said first portion and said second portion.   
     
     
         45 . Method according to  claim 32 , wherein at least one of said first portion and said second portion comprises surface features configured for retaining said particles at least prior to step (c). 
     
     
         46 . Method according to  claim 45 , wherein said surface features includes any one of depressions, dimples, channels and the like. 
     
     
         47 . Method according to  claim 32 , wherein at least some of said particles are made from a metal in common with that of at least one of said first portion and said second portion, or wherein said particles comprise one or more metals which are different from one or more metals constituting said first portion and said second portion. 
     
     
         48 . Method according to  claim 32 , wherein said particles have an effective diameter or characteristic dimension being at least one of the following:
 within a range of about 1*10 −6  m and about 200*10 −6  m;   within a range of about 5*10 −6  m and about 50*10 −6  m;   in the order of about 10 −9  meters.   
     
     
         49 . Method according to  claim 32 , wherein said particles comprise at least one metal or alloy chosen from: aluminium, iron or steel, copper, magnesium, bismuth, lithium, nickel, zinc, magnesium, silver, gold, titanium, and tin; or wherein said particles comprise at least one ceramic chosen from: magnesium oxide, aluminium oxide. 
     
     
         50 . Method according to  claim 32 , wherein foil comprises a metallic foil of thickness between about 1*10 −6  m and about 200*10 −6  m or between about 5*10 −6  m to about 50*10 −6  m. 
     
     
         51 . An article of manufacture comprising a first metal workpiece welded to one or more second metal workpieces according to the method of  claim 32 .