A Non-destructive Strain and Phase Investigation of a Friction Stir Weld Joint between an Al-base Metal Matrix Composite and a Monolithic Al Alloy Using Synchrotron Radiation

Abstract

The through thickness strain and depth resolved phase distribution in a dissimilar friction stir weld (FSW) of monolithic AA2024T3 to AA2014 + 34 vol.% Al₂O₃ is measured non-destructively. The measurements are performed using a novel strain and phase mapping technique. The technique is based on the use of a focused high-energy synchrotron beam, a novel spiral slit system, and an area detector system. The strong asymmetry of the calculated residual stress profiles is mainly due to the dominance of hydrostatic stresses in the metal matrix composite (MMC) side of the weld. Tensile stresses up to + 190 MPa are observed in the Al phase. The large residual stress gradient in the weld centre correlates with the weak mixing of the dissimilar plate materials.