Triaxial strain scanning has been performed on a 7mm thick 7150-aluminium alloy Variable Polarity Plasma
Arc (VPPA) weld using synchrotron X-rays. It has been demonstrated that the use of specific advantageous
(hkl) peaks that occur in this highly textured aerospace alloy plate permits fast deep measurements in reflection
as well as in transmission. The sin2ψ method was also utilised to monitor the variation in deviatoric stress
component (σ11−σ33) across the weld in both the test-piece and a comb like reference specimen used to map the
changes in stress-free lattice spacings over the weld. The results suggest that microstresses have little effect on
macrostress determination, particularly in the Heat Affected Zones (HAZ). Though small in magnitude, the
macrostresses still present in the reference specimen can be allowed for to correct the stress tensor in the plate.
Maximum tensile longitudinal stress values remain unchanged, whereas the stress condition in some parts of
the HAZ is well described as biaxial after the proposed correction.
