The growing demand for more fuel-efficient vehicles to reduce energy consumption and air pollution has made Al-alloys very attractive for light-weight automotive applications. Various Al-alloys with high strength stiffness to weight ratio, good formability, good corrosion and recycling potential compete and replace heavier materials in the car. Age-hardenable Al-Mg-Si alloys are used for visible outer car body panels. As these alloys develop certain surface topographies (waviness) after plastic deformation which can be visible after painting, a quantitative measurement of the surface topography is required.
The present work will focus upon the study of 6xxx Al-alloys for outer car body panels with high requirements of the surface quality. A quantitative correlation between surface irregularities of different types (e.g. Roping, surface roughening, some short wave and long wave phenomena etc.) and corresponding spatial wavelengths is needed. Next, a correlation with final surface appearance of visible auto parts should be made.