Effect of the Plastic Bead Blasting Paint Removal Process on the Fatigue Lives of Thin Skin Materials.

摘要

Room temperature fatigue tests were conducted on unblasted and plastic bead blasted 2024-T6H24 aluminum (thickness = 0.024 inch, long transverse grain direction), 2024-T6H24 aluminum (thickness = 0.016 inch, longitudinal grain direction) and AZ31B-H24 magnesium (thickness = 0.032 inch, longitudinal grain direction for unblasted, long transverse grain direction for plastic bead blasted). For the 0.024 inch thick aluminum (case 1) material, unblasted, type I plastic bead blasted, and type II plastic bead blasted specimens were tested. For the 0.016 inch thick aluminum (case 2) and the magnesium (case 3) materials, unblasted and type I plastic bead blasted specimens were tested. ('Type I' and 'type II' describe two different types of plastic beads). In cases 1 and 2, the Wilcoxon Rank Sum Test was used to compare the fatigue lives of the unblasted and plastic bead blasted specimens. In case 1, type I plastic bead blasting was shown to have a detrimental effect on fatigue life. Statistical evidence was insufficient to reject the null hypothesis for type II plastic bead blasting. In case 2, type I plastic bead blasting was shown to have a detrimental effect on fatigue life. In case 3, no comparison was made because the unblasted specimens were for the longitudinal grain direction and the blasted specimens were for the long transverse grain direction.