Abrasive blast contour machining to remove surface and near-surface crack initiation

Abstract

A multi-axis machine includes a controller operable to control a nozzle which ejects a particulate material relative to a part surface to maintain a compound angle and predetermined stand off distance to remove surface and near-surface crack initiation sites.

1 . A multi-axis machine comprising:
 a nozzle operable to eject a particulate matter; and   a controller operable to control said nozzle relative to a part surface to maintain a compound angle and predetermined stand off distance to remove surface and near-surface crack initiation sites.   
     
     
         2 . The multi-axis machine as recited in  claim 1 , wherein said nozzle directs an aluminum oxide powder at a constant pressure. 
     
     
         3 . The multi-axis machine as recited in  claim 1 , wherein said compound angle is never perpendicular to a workpiece surface. 
     
     
         4 . The multi-axis machine as recited in  claim 1 , further comprising maintaining a uniform erosion rate across all features of a workpiece surface. 
     
     
         5 . The multi-axis machine as recited in  claim 4 , wherein said uniform erosion rate removes at least 0.002 inches of material. 
     
     
         6 . A method of surface machining comprising:
 removing surface and near-surface crack initiation sites with a particulate matter.   
     
     
         7 . The method as recited in  claim 6 , wherein said removing comprises:
 maintaining a compound angle and predetermined stand off distance between a nozzle which ejects the particulate matter and a workpiece surface.   
     
     
         8 . The method as recited in  claim 6 , wherein said removing comprises:
 maintaining a uniform erosion rate across all features of a workpiece surface   
     
     
         9 . The method as recited in  claim 8 , wherein the uniform erosion rate removes at least 0.002 inches of material. 
     
     
         10 . The method as recited in  claim 8 , wherein maintaining the uniform erosion rate comprises:
 moving the nozzle through a multi-axis motion machine with variable velocity control.