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Iordache M.,University of Pitesti | Badulescu C.,ENSTA Bretagne | Iacomi D.,University of Pitesti | Nitu E.,University of Pitesti | Ciuca C.,National Research and Development Institute for Welding and Material Testing
IOP Conference Series: Materials Science and Engineering | Year: 2016

Friction Stir Welding (FSW) is a solid state joining process that relies on frictional heating and plastic deformation realized at the interaction between a non-consumable welding tool that rotates on the contact surfaces of the combined parts. The experiments are often time consuming and costly. To overcome these problems, numerical analysis has frequently been used in last years. Several simplified numerical models were designed to elucidate various aspects of the complex thermo-mechanical phenomena associated with FSW. This research investigates a thermo-mechanical finite element model based on Coupled Eulerian Lagrangian method to simulate the friction stir welding of the AA 6082-T6 alloy. Abaqus/cae software is used in order to simulate the welding stage of the Friction Stir Welding process. This paper presents the steps of the numerical simulation using the finite elements method, in order to evaluate the boundary conditions of the model and the geometry of the tools by using the Coupled Eulerian Lagrangian method. © Published under licence by IOP Publishing Ltd.


Sirbu N.A.,Polytechnic University of Timişoara | Sirbu N.A.,National Research and Development Institute for Welding and Material Testing | Serban V.-A.,Polytechnic University of Timişoara | Savu S.,University of Craiova
Materiale Plastice | Year: 2014

The paper present the experimental results of a comparative research study between classical and ultrasonically processing by extrusion of the HDPE-220J (High Density Polyethylene) polymeric material. For this material, often used in engineering, have been obtained, in flow activated using ultrasonic waves, relatives increases of the flow rate up to 77% of polymer flowing through extrusion compared with the processing without ultrasounds. These results have been obtained in laminar flowing and no imperfections have been presented due to the extrusion process. The experimental results of the state transition using the differential scanning calorimetry analysis DSC (Differential Scanning Calorimeter), realized for classical and ultrasonically flow activation, confirms that ultrasonic microvibrations produced no changes in the internal structure of the polymer. The ultrasonic device used in this research is subject to a patent application registered at OSIM with number A/00979/2013.


Oanca O.,National Research and Development Institute for Welding and Material Testing | Sirbu N.A.,National Research and Development Institute for Welding and Material Testing | Perianu I.A.,National Research and Development Institute for Welding and Material Testing
Archives of Materials Science and Engineering | Year: 2014

Purpose: This paper presents the general aspects concerning the development of innovative ultrasonic welding technologies at ISIM Timisoara and the advantages of using ultrasonic metal joining, compared with conventional joining methods, in the automotive industry for joining multiwire connectors from copper and aluminium. Design/methodology/approach: In discussion is joining ultrasound multiwire copper conductors on copper 99.95% substrate, ultrasonic welding of copper and aluminium multiwire conductors onto Al99.95% support and welding dissimilar materials multiwire copper and aluminium conductors onto copper support. Findings: Comparison of experimental results through mechanical testing, electrical conductivity testing, digital microscopy imaging and ultrasonic compaction highlights the potential development and use of aluminium as a replacement of connection to the copper wiring in automotive equipment. Practical limitations/implications: The experimental results through mechanical testing, electrical conductivity, digital imaging microscopy, ultrasonic compacting, realized on Cu-Cu, Al-Al and Al-Cu samples, underscore the potential for using aluminium as a substitute for copper multiwire connectors in automotive industry. Originality/value: Statistics show that the automotive industry together with aerospace and military equipment industries represent by excellence the innovative technologies drive and consist as a sensitive indicator for society changes in the tech areas. © International OCSCO World Press. All rights reserved. 2014.

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