"Parts with circular and hallow profiles such as pipes, cylinders and vessels have wide applications in a variety of industries as one of the most important engineering parts. Therefore, formation of nanostructure and its resulting strength in those parts may be of great interest", Mohammad Sadeq Mohebbi, PhD student at Materials Science and Engineering School, Sharif University of Technology, told Iran Nanotechnology Initiative Council, according to a report by Farsnews.
Elaborating on the procedure of the research, he said, "We first introduced a process called Spin-Bonding (SB) based on flow forming process to interconnect pipes and make a composite multilayered pipe."
"Two pipes or vessels, after an appropriate surface treatment, were placed on each other and their thicknesses were decreased by flow forming process. It led to the establishment of connection between two layers and production of a two layered pipe or vessel. Afterwards, the idea of severe plastic deformation by applying different cycles of SB process to pipes was proposed and developed," Mohebbi added.
He further explained about the results of the research, and said, "This project was first undertaken for aluminum pipes AA1050 for four cycles so that a sixteen-layered pipe was fabricated. According to TEM and EBSD tests, application of SPD resulted in changing the initial grain size from 30 µm to 419 and 186 µm. It is notable that their yield stress and tensile strength increased from 36 and 112 MPa to 195 and 235 MPa respectively."