Stress Analysis
S. Khalilpourazary; M. Zadshakoyan; S. H. Hoseini
Abstract
In recent decades, the industrial applications of refined grained pure copper and its alloys have been expanded. The properties such as high strength, high density, and low deformability make these alloys more attractive. Hence, investigating the fracture mechanism of refined grained copper is of great ...
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In recent decades, the industrial applications of refined grained pure copper and its alloys have been expanded. The properties such as high strength, high density, and low deformability make these alloys more attractive. Hence, investigating the fracture mechanism of refined grained copper is of great significance. In this study, the fracture analysis of copper is investigated using the equal channel angular pressing process. Experimental results on metal alloys demonstrate that stress states should be incorporated in the constitutive equations. Therefore, the fracture process is analyzed by focusing on its relationship with the Lode angle variable. To prepare the equal channel angular processed specimens, a die set is manufactured, and tensile strength tests are carried out on dog-bone and notched flat plate specimens up to fracture. In addition, the mean value of grain sizes of the copper specimens is evaluated. The results demonstrate that the grain refining process profoundly enhances the load-carrying capacity of copper specimens. Moreover, the dog-bone tensile tests clearly show that the peak value of the strain hardening in refined grained copper occurs up to two passes, and after two passes the strain hardening drops. Furthermore, the results reveal that the Lode anglel variable has a significant influence on the failure of the refined grained copper specimens.
Manufacturing Processes
Saman Khalilpourazary; jamal ahmadi
Abstract
Reaming is a common finishing process for improving the drilled holes surface quality. Choosing an appropriate finishing method in drilling process has a significant effect on the surface quality of holes and in decreasing the process total cost and time. In this study, four similar holes were drilled ...
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Reaming is a common finishing process for improving the drilled holes surface quality. Choosing an appropriate finishing method in drilling process has a significant effect on the surface quality of holes and in decreasing the process total cost and time. In this study, four similar holes were drilled on the AISI 4340 workpiece with different two pair feed rates. The drilling process was performed with a conventional cutting fluid, an emulsion of water and ECOCOOL 3015 GS-W. The surface roughness values after drilling process were measured using a portable roughness tester. Then, two distinct sizes of alumina micro-particles were used in the cutting fluid discretely to perform finishing process of the holes with a specific cylindrical tool. A comparison of the surface roughness measurements after the finishing process showed a significant decrease in the arithmetic surface roughness and ten-point mean roughness values of the drilled holes. The values were very close to the surface roughness limits in reaming process of the holes.