Friction plunge riveting process

Abstract

A method of joining a pair of metal components with a rivet having a hardness that is substantially similar to at least one of the metal components. The metal components are stack upon each other and the rivet is rotated and simultaneously plunged in the metal components under pressure to friction weld and metallurgically bond the rivet to the metal components.

We claim:  
     
         1 . A method of joining a pair of metal components comprising the steps of: 
 (a) placing a first metal component having a first exposed continuous surface and a second metal component having a second exposed surface in overlapping relationship to each other;    (b) providing a metal rivet having a head and a tip opposite the head for entering into the first and second components; and    (c) rotating the rivet about its longitudinal axis and simultaneously plunging the rivet through the first component continuous surface and into the second component, wherein the hardness of the metal rivet is substantially similar to the hardness of at least one of the first and second components, such that the metal of the rivet and the first and second components plastically deform; and    (d) solidifying the plasticized metal to produce a joint between the rivet and each of the first and second components.    
     
     
         2 . The method of  claim 1  wherein the rivet tip is pointed.  
     
     
         3 . The method of  claim 2  wherein a final position of the rivet tip is within the second component.  
     
     
         4 . The method of  claim 2  wherein a final position of the rivet tip is flush with the second exposed surface.  
     
     
         5 . The method of  claim 2  wherein a final position of the rivet tip is exterior to the second component.  
     
     
         6 . The method of  claim 1  wherein the rivet defines a helical groove along an exterior surface of the rivet.  
     
     
         7 . The method of  claim 1  wherein the rivet includes means for hiding flash produced in the step of plunging and rotating the rivet.  
     
     
         8 . The method of  claim 7  wherein the rivet includes a flange and a lip extending therefrom, the flange and lip thereby defining a recess for collecting flash between the rivet and the first exposed surface.  
     
     
         9 . The method of  claim 1  wherein the rivet tip defines a bore.  
     
     
         10 . The method of  claim 9  wherein the bore extends partially through the rivet.  
     
     
         11 . The method of  claim 9  wherein the bore extends completely through the rivet.  
     
     
         12 . The method of  claim 1  wherein the head of the rivet includes means for engaging another component.  
     
     
         13 . The method of  claim 1  further comprising joining a third metal component to the second component by the steps of: 
 (i) positioning the third component having a third exposed surface in overlapping relationship to the second exposed surface;  
 (ii) providing another metal rivet having a head and a tip opposite the head for entering into the third and second components; and  
 (iii) rotating the other rivet about its longitudinal axis and simultaneously plunging the other rivet through the third component exposed surface and into the second component, wherein the hardness of the other metal rivet is substantially similar to the hardness of one of the third and second components.  
 
     
     
         14 . The method of  claim 13  wherein steps (c) and (iii) are performed simultaneously.  
     
     
         15 . The method of  claim 1  wherein the first and second metal components and the rivet each comprise aluminum or an aluminum alloy.  
     
     
         16 . The method of  claim 15  wherein at least one of the first and second metal components is a clad product.  
     
     
         17 . A composite metal product comprising: 
 a first metal component having a first exposed surface;    a second metal component underlying the first component; and    a metal rivet extending from said first exposed surface into the second metal component, said rivet being friction welded to each of said first and second components, wherein the metal of said rivet has a hardness substantially similar to at least one of the first and second metal components.    
     
     
         18 . The composite metal product of  claim 17  wherein the first metal and second metal components and the rivet each comprise aluminum or an aluminum alloy.  
     
     
         19 . The composite metal product of  claim 18  wherein at least one of the first and second metal components is a clad product.  
     
     
         20 . The composite metal product of  claim 17  wherein at least about 50% of the alloying components the first and second components and the rivet are the same.  
     
     
         21 . A system for joining a first metal component to a second metal component with a rivet, wherein the hardness of the rivet is substantially similar to the hardness of at least one of the first and second components, said system comprising: 
 a clamp positioned on a continuous first exposed surface of the first component for maintaining the first component adjacent the second component;    a backing anvil for supporting a second exposed surface of the second component adjacent the first component; and    means for rotating and plunging the rivet through the continuous first exposed surface and into the second component to produce a region of plasticized metal between the rivet and each of the first and second components, the plasticized metal being solidifiable to form a friction weld between the rivet and each of the first and second components.