MS13-P06 Measurement of relaxation-free stress profiles in aluminium by multireflection grazing incidence X-ray diffraction with different wavelengths. Victor Righetti (Laboratório de Plasmas e Processos - Instituto Tecnológico de Aeronáutica, São José dos Campos, Brazil) Tiago Campos (Laboratório de Plasmas e Processos - Instituto Tecnológico de Aeronáutica, São José dos Campos, Brazil) Lucas Robatto (Centro de Competência em Manufatura - Instituto Tecnológico de Aeronáutica, São José dos Campos, Brazil) Gilmar Thim (Laboratório de Plasmas e Processos - Instituto Tecnológico de Aeronáutica, São José dos Campos, Brazil)email: forarodas@gmail.comThe state of residual stresses is of fundamental importance to the mechanical properties of many metals. Resulting properties are function of not only surface, but also the subsurface stress state, usually beyond the penetration depth of most X-ray sources. To circumvent this limitation conventional methods of stress profiling relies on some kind of material removal such as electropolishing or acid polishing, which are known to cause stress relaxation [1], compromising the reliability of such profiles.
Multireflection grazing incidence X-ray diffraction (MGIXD) geometry is seen as an alternative for obtaining relaxation-free, nondestructive residual stress profiles [2], potentially resulting in major revisions of the understanding of subsurface stress influence in metals' mechanical properties.
We discuss here the application of the MGIXD geometry for stress profiling in aeronautical aluminium. In this study a PANalytical Empyrean diffractometer equipped with conventional (Cu) and hard (Ag) sources was used to obtain residual stress profiles of shot peened 7050 aeronautical aluminium in depths up to 200 μm. With this results, comparisons with conventional (destructive) stress profiling methods was also made possible.
References:

[1] Prevey P. S. Residual stress in design. In: Young WB, editor. Process and materials selection (1987). Metals Park, OH: ASM.



[2] Skrzypek, S. J., Baczmański, A., Ratuszek, W. & Kusior, E. (2001). J Appl Cryst, 34, 427–435.

Keywords: residual stress, MGIXD