Effect of non-equal channel angular pressing on milling-induced residual stress

Abstract

The present paper provides a comparative study of in-depth milling-induced residual stress (MIRS) measurement in Al 3003 processed by non-equal channel angular pressing (NECAP) which exhibit fundamental knowledge to understand the MIRS in grain refinement materials. To evaluate MIRS, combination of two commonly used experimental methods, X-ray diffraction (XRD) and the incremental hole drilling method with digital image correlation (IHD-DIC), have been employed. Billets of Al 3003 with the same dimensions before and after NECAP process have been used as workpieces that are machined under the same milling conditions, including the cutting speed (565 rev/min), depth of cut (1.5 mm), and feed rate (200 mm/min). MIRS on the surface and along the depth of the workpieces has been measured in the cutting direction ( xx ) and perpendicular to the cutting direction ( yy ). The experimental results for the range of values studied revealed that MIRS in Al3003 subjected to the NECAP process is shifted from tensile to compressive and notably surface MIRS in both directions is lower (19.22% for xx and 17.38% for yy ) than that found in workpiece before the process.