Interior Residual Stress of Bulk Nanocrystalline Aluminum Measured by Short-Wavelength X-ray Diffraction Method

A self-developed SWXRD-1000 short-wavelength X-ray diffractometer was used to measure interior residual stress of bulk nanocrystalline aluminum before and after different stress-relief heat treatment; In order to study the distribution of residual stress along thickness direction, surface residual stress of bulk nanocrystalline aluminum before heat treatment was measured by Xstress-3000 stress diffractometer. The results show that grain orientation distribution inside nanocrystalline aluminum was uniform. The interior residual stress in sample center decreased with the increase of heat treatment temperature, and the radial residual stress in sample center decreased from 113 MPa(before heat treatment) to 4 MPa, and the tangential residual stress in sample center decreased from 91 MPa (before heat treatment) to 38 MPa. For the sample before heat treatment, the distribution of residual stress along thickness direction showed external compressive stress and interior tensile stress, and the higher interior residual stress along diameter direction located in center position, and the lower interior residual stress located in the two sides, and the stress near center position was compressive residual stress.