• فهرست مقالات Charpy Impact Test

      • دسترسی آزاد مقاله

        1 - Investigation of The Effect of Notch Tip Radius on Fracture Energy of Charpy in 7075 Aluminium Alloy
        Ali Hossein zadeh Mohammad Reza Maraki Mohsen Sadidi
        In the present study Charpy impact tests on a 7075-T651 aluminium alloy with full size (55×10×10 mm) with different notch tip radius (range of 0.19 to 0.40 mm) were conducted and the fracture energy was measured. The experimental results showed that the rela چکیده کامل
        In the present study Charpy impact tests on a 7075-T651 aluminium alloy with full size (55×10×10 mm) with different notch tip radius (range of 0.19 to 0.40 mm) were conducted and the fracture energy was measured. The experimental results showed that the relationship between the fracture energy (E) and the notch tip radius of the Charpy samples (r) for the tested Aluminium is E=18.052r+1.741. Using this relationship, the Charpy energy can be determined for this Aluminium for any notch tip radius. Fracture surfaces revealed an intergranular failure for base metal in longitudinal direction, that a predominately brittle failure (cleavage) with some insights of ductile characteristics was observed. Moreover, with increasing notch tip radius, cracked particles were observed and some microvoids were nucleated, i.e., ductile fracture. Changes in the primary crack notch cause a change in the stress intensity factor adjacent to the crack tip, where the fracture energy in the Charpy Impact Test is subjected to the primary crack notch. پرونده مقاله
      • دسترسی آزاد مقاله

        2 - Effect of Inter-Cavity Spacing and Heat Treatment in Friction Stir Processing/Welding (FSP/FSW) Al7075 Composites Containing Al2O3 and Graphene Nanomaterials using Charpy Impact Test
        Ali Hosseinzadeh Mahmoud Shariati Danial Ghahremani-moghadam Mohammad Reza Maraki
        In this research, the friction stir process by adding Al2O3 and graphene nanoparticles at two different distances have been investigated. Nanoparticles are inserted in cavities with a diameter of 2 mm and a depth of 3 mm. Nanoparticles of Al2O3, graphene, and equal comp چکیده کامل
        In this research, the friction stir process by adding Al2O3 and graphene nanoparticles at two different distances have been investigated. Nanoparticles are inserted in cavities with a diameter of 2 mm and a depth of 3 mm. Nanoparticles of Al2O3, graphene, and equal compositions of Al2O3 and graphene, each with two cavity spacings of 8 and 10 mm, have been performed in six different groups of friction stir process. From each group, Six Charpy specimens were separated. Charpy impact test was performed on six samples, three of which were heat-treated after the friction stir process. Charpy impact test has shown that the specimens have higher fracture energy after heat treatment. Also, in all cases, the fracture energy at the distance between the two cavities are10 mm more than the distance of 8 mm, this is since nanoparticles do not accumulate at a more distance. Also, to observe the resulting microstructures using optical microscopy and scanning electron microscopy on the friction welding process and the fracture surface of Charpy impact specimens were performed. The results show that the nanoparticles are accumulated in some samples and well dispersed in the materials in others. پرونده مقاله