Residual stresses can meaningfully influence on the operation of a part. They are almost created by all fabrication processes. In this study, slitting method was used to obtain the residual stress profile through the thickness of equal-channel angular rolled aluminum strips. Furthermore, uncertainty analysis of the measured residual stresses was performed. The measurement and model uncertainties were considered in the uncertainty analysis, and the effect of each one on the total uncertainty was investigated. Besides, to study the through-depth residual stress distribution numerically, finite element simulation of equal-channel angular rolling process in route C was done. In route C, the strip should be rotated around the longitudinal axis by 180°after each successive pass. The results showed the important role of both measurement and model uncertainties in the calculation of total uncertainty. The maximum tensile residual stresses of the control, 1-pass and 2-pass samples were 7.59, 64.4 and 85.11 MPa, respectively, and the root mean square total uncertainty of them were 1.47, 2.43 and 5.12 MPa, respectively. There was a good agreement between experimental and numerical results.

One of the important parameters that can influence on performance of a part and its life is residual stress. All manufacturing processes can create residual stress in different ranges. Laser bending is one of the thermoforming processes that has been used in different industries. The aim of this study is investigation of through-thickness residual stress profile of Grade 2 titanium samples that were subjected to laser bending process. Slitting method was used to measure the residual stress profile experimentally. Both series expansion and pulse-regularization methods that are common computational techniques in the slitting method were employed to calculate the residual stress. Besides, finite element simulation of the laser bending process was done to study the through-depth residual stress distribution numerically. The results of two computational techniques were compared to each other and with the finite element method results. Furthermore, the effect of laser bending process on surface roughness and microhardness of the samples at the heat-affected zone was investigated. The results showed that laser bending process can induce considerable residual stress in the heataffected zone of the part. Comparing the experimental and finite element method results showed good agreement between them. In comparison with the control sample, both surface roughness and microhardness of the samples increased after the laser bending process.

Equal channel angular rolling process is defined as a severe plastic deformation method that imposes very large plastic strain on a material in order to enhance its mechanical properties and grain structure refinement. In this study, residual stress profiles through the thickness of St12 strips that were subjected to different passes of equal channel angular rolling were investigated by slitting method. Also, the effects of different routes of equal channel angular rolling (A and C) were studied on the mechanical properties and residual stress. Furthermore, the effect of post annealing on the mechanical properties and residual stress of 4-pass equal channel angular rolled strip was examined. The results showed significant increase in the yield strength, ultimate tensile strength, and micro hardness of the samples in both routes. But the elongation decreased. Considerable magnitude of residual stress was created through the thickness of equal channel angular rolled samples such that the maximum tensile residual stress of some samples raised to about half of the corresponding yield strength. The maximum magnitude of residual stress in route C was smaller than that in route A.

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Laser bending is one of the thermal forming processes which in each pass of it, the temperature of sample increases at heat-affected zone during irradiation time considerably and then it cools to near ambient temperature after passing the laser beam. Consequently, it can be predicted that the process can induce significant residual stress in the sample. In this article, laser bending process of the explosive welded steel-titanium bimetal sample was done and the through-thickness residual stress profile of it was investigated by the slitting method experimentally. The pulse-regularization approach was used to calculate the residual stress in the bimetal sample. Also, simulation of the laser bending process was performed and the numerical residual stress profile was compared with the experimental one. Furthermore, the effects of process parameters including laser power, scanning velocity and number of scanning passes on the bending angle of bimetal samples were investigated experimentally. Besides, the effect of laser bending process on the surface microhardness was studied. The results demonstrated that the laser bending process can create significant residual stress at the heataffected zone of specimen. In the residual stress profile of bimetal sample, a discontinuity was seen at the interface of the materials, as was expected. There was a good agreement between experimental and numerical results. The maximum compressive and tensile residual stresses raised by increase laser power and number of scanning passes. Both of them reduced by magnifying scanning velocity. The laser bending process can increase the surface microhardness at the heat-affected zone which can be attributed to the reduction of grain size at the heat-affected zone.