EFFECTS OF SHORT PULSED LASER CLEANING ON METAL SURFACES: Paper # Macro 102

摘要

Lasers have been demonstrated to be very efficient in cleaning processes, removing layers of unwanted materials, including grease, paint, and oxides. Laser cleaning is used in many industries, including automotive, aerospace, and food processing. High power CO~2 lasers and other continuous wave lasers are frequently used; however, the high peak intensity of short pulsed laser is needed to reach the ablation threshold of some materials. With short pulsed lasers it becomes increasingly critical to evaluate the effect of the cleaning process on the underlying base material. While the cleaning process parameters can be on the edge of the ablation threshold of the underlying metal, the surface is typically only re-melted, structured, or lightly textured. Process parameters to remove powder coated white paint from aluminum and steel have been determined using an IR disk laser with 30 nanosecond pulses. These will be used to evaluate the effects of the initial cleaning on the metal surface. Subsequent cleaning cycles will also be performed to evaluate any compounding effects. The effect on the metal surface will be characterized through SEM and EDS. Bare aluminum, steel, and copper are also laser cleaned to evaluate the effect of these parameters and compare it to the surrounding uncleaned portion of the part. The structuring of the material will be shown, which can increase the adhesion for the next processing steps if the material is going to have another glue, coating, or paint applied.