A NEW SAMPLE PREPARATION TECHNIQUE FOR THE EXAMINATION AND ANALYSIS OF PAINT FILM DEFECTS

A paint film cross-sectioning technique has been developed which allow s simultaneous characterization of a paint defect and the underlying s ubstrate and pretreatment. The advantages of the technique include spe ed, accuracy of cross-sectioning the defect, simplicity, lack of polis hing artifacts, and a pseudo-three-dimensional perspective which uniqu ely reveals the relationship between the defect, paint film and substr ate. Disadvantages include possible damage to the sample or removal of contaminants by the solvents used. The prepared sample may be examine d using an optical or scanning electron microscope (SEM), and analyzed by x-ray fluorescence (XRF) or other methods. The technique has prove n especially useful tor pinpointing the cause of defects resulting fro m interaction of the substrate or pretreatment with the paint film. Th is paper describes the practice of the technique and its application t o solving production problems related to paint defects.