Dealing with Surface Blackening in CNC Machined Aluminum Alloy 1. Causes of Deformation in Aluminum Alloy Parts Processing (1)Deformation due to internal stress in the blank. (2)Deformation caused by cutting forces and heat during machining. (3)Deformation caused by clamping forces. 2. Technological Measures to Reduce CNC Parts Processing Deformation (1)Reducing Internal Stress in Blanks: Use