Sharif Digital Repository

Severely deformed commercial pure aluminum sheets by constrained groove pressing are direct and crossrolled. The grain size evolution and dislocation density during rolling are studied using Williamson-Hall analysis on x-ray diffraction patterns of the deformed samples. These results and optical microscopy observations show that subsequent direct or cross-rolling of constrained groove pressed aluminum can produce elongated fine grains. The minimum crystallite size is achieved after cross-rolling of constrained groove pressed samples. By direct-rolling or cross-rolling of annealed sheet, the maximum intensity in x-ray diffraction patterns remains on (200) like annealed aluminum but... 

Residual stresses are inherent in parts manufactured using the wire + arc additive manufacturing (WAAM) technique, resulting in unpredictable mechanical response and structural integrity (Colegrove et al.: J Mater Process Technol 213:1782-1791, 2013). An effective post-processing technique, which enhances the mechanical properties of WAAM parts, is rolling. This study investigates the vertical and pinch rolling effects on residual stress distribution in WAAM components. Initially, a WAAM model was created using a thermo-mechanical finite element modelling approach and validated against the experimental results. Subsequent to the validation of the model, the effect of the main parameters... 

Tailored welded blanks (TWBs) technology can give the important possibilities to obtain components in the automobile industry. Friction stir welding (FSW) is a joining approach, which can adhere parts well with desired properties in weld zone. In this article, the main aim is investigation the effect of weld zone orientation on forming limit diagram (FLD) of the TWBs using experimental and finite element model. Three TWBs are produced FSW with three different orientations of weld zones including 00, 450 and 900 against major stress direction. The microstructure of the weld zones is divided and then observed via metallography procedures. Tensile tests are carried out to determine the...