2019 Volume 83 Issue 5 Pages 157-165
Ni polycrystals were processed by accumulative roll-bonding (ARB) of 7 cycles and tensile specimens were cut from the ultra-fine grained (UFG) Ni after ARB. Microstructure and crystallographic orientation of UFG Ni were observed by scanning electron microscopy (SEM) and electron back scattering diffraction (EBSD) method. Three textures component, Copper, Brass and S orientations were found in UFG Ni.
Three specimens for tensile tests having tensile directions parallel with RD, TD and 45D were cut from UFG Ni. RD and TD indicate rolling and transverse directions of ARB process respectively, and 45D indicates a 45 degree direction between RD and TD. For these specimens, in-situ XRD measurements were performed during tensile deformation. Elastic strains during tensile deformation were calculated from values of peak shift for various diffraction planes obtained by the XRD measurements. For RD specimen, the elastic strains during initial deformation for various diffraction planes were almost the same. However, for 45D specimen, the elastic strains for various diffraction planes were different even at initial loading. TD specimen showed behavior like RD specimen. The difference in the elastic behavior between the specimens are discussed by considering difference in crystallographic directions of grains along tensile directions in the specimens which is caused by the textures generated after ARB.
