Abstract
A surface roughening phenomenon was investigated using commercially pure aluminium sheets deformed plastically along various proportional strain paths. Surface profiles were measured in three directions of a major principal strainε1, a minor principal strain ε2 and 45 degrees toε1 direction. The mean value of Ra in the three directions could be expressed by the equation: R^-a = 3.14εd, where εd is an absolute value of principal strain vector in-plane, independently of the strain path. Both Ra and the wavelength λm at spectrum maximum showed a relatively large difference between ε1 and ε2 direction in the case of balanced bi-axial tensile path. The anisotropic geometry of surface topography corresponded with the direction of the maximum shear stress plane in the bulk metal.
