Method for surface strengthening and smoothening of metallic components

Abstract

With a method for surface strengthening and smoothening of metallic components, in particular of rotors or rotor drums ( 7 ) with integral blading for aircraft engines, the components are loaded in a vessel ( 2 ) which is filled with strengthening elements ( 10 ). A tumbling movement is performed by which the metallic components are strengthened and smoothened by a relative movement between the workpiece surface and the strengthening elements in one process step. The strengthening elements ( 10 ) have a circumferential, rounded edge area, or compressive strengthening area ( 13 ) for strengthening the surface, and, extending therefrom on both sides, a flatly curved smoothening area ( 14 ) for smoothening the surface roughened by strengthening. With low time and apparatus investment, workpieces can be provided that feature high fatigue strength and advantageous aerodynamic properties.

1 . A method for surface strengthening and smoothening a metallic component, comprising:
 providing strengthening elements having circumferentially rounded compressive strengthening areas for strengthening a surface of the metallic component, and, extending therefrom on both sides, flatly curved smoothening areas for smoothening the surface roughened by strengthening; and   placing the metallic component and a plurality of the strengthening elements in a vessel, and creating a relative movement between the surface of the metallic component and the strengthening elements to simultaneously strengthen and smooth the surface of the metallic component.   
     
     
         2 . The method of  claim 1 , and further comprising:
 causing the strengthening elements to circulate horizontally and vertically within the vessel, as well as to have vibratory movement;   adjusting a mass of each strengthening element to these movements; and   causing the strengthening elements to access confined areas of the metallic component via a flattened shape of the strengthening elements.   
     
     
         3 . The method of  claim 2 , and further comprising masking surface areas of the metallic component which are not to be strengthened. 
     
     
         4 . The method of  claim 3 , and further comprising providing the compressive strengthening areas in at least one of a circular and an elliptical form. 
     
     
         5 . The method of  claim 4 , and further comprising providing the compressive strengthening area of each strengthening element with cross-sectionally circle segment form having a small radius, and providing the smoothening areas in spherical segment form having a several times larger radius then the compressive strengthening area. 
     
     
         6 . The method of  claim 1 , and further comprising providing the strengthening elements as spheres, each with a formed-on, circumferential ring, with a rounded free edge of the ring forming the compressive strengthening area and the two free spherical surfaces forming the smoothening area. 
     
     
         7 . The method of  claim 1 , and further comprising providing the strengthening elements as flattened spheres whose circumferential small-radius edge area forms the compressive strengthening area and whose opposite large-radius areas form the smoothening areas. 
     
     
         8 . The method of  claim 7 , and further comprising providing the strengthening elements in lenticular form. 
     
     
         9 . The method of  claim 7 , and further comprising providing the strengthening elements in disk-shaped form. 
     
     
         10 . The method of  claim 4 , and further comprising providing the strengthening elements in stainless steel. 
     
     
         11 . The method of  claim 1 , wherein the metallic component is at least one of an aircraft engine rotor and an aircraft engine rotor drum.