Monday 27 October 2003

Friction Stir Welding of Light and Heavy Reactive Materials. A. Landau, S. Haroush , A. Venkert, and S. Eden, Department of Materials Engineering, Ben-Gurion University of the Negev, Beer-Sheva, Israel; and M. Talianker, NR

In this work three materials were welded using the Friction Stir Welding (FSW) technique, Al-5083, Mg-AZ91 and Uranium 0.75wt.%Ti alloy, in its quenched condition. While FSW of Al and Mg alloys were comprehensively reported in the literature, there is no information regarding FSW of uranium and its alloys. In the case of light alloys, once the tool and the welding parameters were developed, a high quality welds were produced. On the other hand, the uranium weld quality was not good enough, due to oxidizing and eutectic reactions with the tool material.
Adopting the FSW technique for welding uranium alloys was chosen in order to learn the potential use of this technique for heavy and reactive alloys. The use of Uranium 0.75wt.%Ti in its quenched condition enabled the assessment of the FSW process kinetics due to the increase of hardness and the reduction of ductility as a function of aging condition. A special fixture was designed and fabricated enabling mapping the temperature field evolved in the welded sample during the process.
It was proved that Uranium alloy can be welded using the FSW technique. Yet, the welds quality was not uniform due to an extensive wear of the pin tool made of steel. A (Ti,Al)N coated WC tool was developed and primary results show that the extent of wear was significantly reduced. An optimization of the process parameters is currently in progress.

Friction Stir Welding of Aluminum and Copper Plates. A. Polar, Universidad Nacional de San Agustín, Arequipa, Perú; T. Shah and J.E. Indacochea, University of Illinois at Chicago, Chicago, Illinois, USA.

Friction stir welding of 3.0 mm thick 6061-T6 aluminum and 1.6 mm annealed 10100 copper (99.99) was performed. The welding tool used is non-conventional where the pin is off-centered from the main axis of the tool. The plasticized metal flow and development of weld defects at the start of the welding fabrication is analyzed. A detailed metallurgical characterization of the welds and mechanical evaluation of the crosswelds was carried out. It was found that at the start of the weld the nugget showed extensive porosity, incomplete filling and cracking for both the aluminum as well as the copper plates. There were differences in terms of the metal flows and microstructure characteristics between the two metals based in part to their differences in melting temperatures. The same tool and welding parameters were used in each case. It was observed that when using low rotation speeds, a “cold” stirring of the low plasticized material is produced and a fine grain structure is produced, but the weld nugget is incomplete. On the other hand, by increasing the rotational speed a hotter process results that leads to an improved weld nugget, but a coarser grain structure develops that compromises the mechanical strength of the weld.

Friction Stir Welding of Aluminum and Copper Plates.

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Application of Modern Hybrid Welding Technology for Welding of High Corrosion Resistant Ni-base Alloys in Environmental Technology. H. Herold, and M. Zinke, Universitat Magdeburg, Germany.

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Organization of the Welding Shop and Laboratory at Mackenzie Presbyterian University in Sao Paulo A Well Succeded Experience. A. Goncalves, P. Martins, G. Crisi, and D. Benites, Mackenzie Presbyterian University in Sao Paulo, Brasil.

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Tuesday 28 October 2003

Metallurgical and Mechanical Properties of Inconel 600 and Stellite Coating. M. Vite, M. Castillo, G. Villa and L. Hernandez, Sección de Estudios de Postgrado e Investigación, Departamento de Mecánica, ESIME, Colombia.

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Optimization of Strength in Laser Micro Welding of Stainless Steel. J. Macedo, Industrial and Manufacturing Engineering Department, California Polytechnic State University, San Luis Obispo, and E. Kahatt, SEQUENOM Inc. San Diego

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Welding of Aluminum by the MIG Process with Indirect Electric Arc. R. Garcia, V.H. Lopez, Research Fellows at Instituto de Investigaciones Metalúrgicas UMSNH, México, Advanced Materials Group, University of Nottingham, United Kingdom.

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Creep Rupture Properties of Bainitic Steel Weldments for Service in Fossil Power Plants. J.E. Indacochea and G. Wang, University of Illinois at Chicago, Civil & Materials Engineering Dept., Chicago, Illinois, USA.

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Electrodo tubular para el recubrimiento superficial de piezas sometidas a impacto y abrasion moderada. M. Rodriguez, Universidad Central de las Villas, Centro de Investigaciones de Soldadura, Santa Clara, Cuba.

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Wednesday 29 October 2003

Gas Metal Arc Welding in Robot Cells. T. North, P. Su, and S. Nekrasov, University of Toronto, Department of Materials Science and Engineering, Toronto, Ontario, Canada.

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Fundamentos de la Resistencia a la Fatiga en Uniones Soldadas. P. Coloma EXSA S.A, Lima- Perú.

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Modelization of the Thermal Cycle in a Multipass Welded Joint by Finite Elements Method. C. Zuniga, Q. Valverde and C. Fosca, Pontificia Universidad Católica del Perú, Lima, Perú.

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Quality Underwater Wet Welding: Porosity and Microstructural Steel Welds. S. Liu, Colorado School of Mines, Center for Welding, Joining, and Coatings Research, Golden, Colorado, USA.

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Application of DIN EN 287-1 and EN 288-3 Standards for the Qualification of Welding Procedures. D. Scholze, German Welding Society (DVS), Germany.

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Training in Welding Field by E-learning. PUCP Experience. C. Fosca, and P. Lean, Area de Tecnología de Materiales, Pontificia Universidad Católica del Perú, Lima, Perú.

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Joining by Compression Processes. M. Mallqui, Universidade Federal do Rio Grande do Sul, Brasil.

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The German Welding Society (DVS) and its Permanent Contribution to the Welding Technological Innovation in the German Economy. D. Scholze, German Welding Society (DVS), Germany.

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Reparación por Soldadura de Ollas de Fundición, Labios de Convertidor y Cucharas para la Industria del Cobre. J. Merzthal, and J. Guardia, EXSA S.A., Lima, Perú.

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Reparación por Soldadura de Tubería Resistente al Calor. S. Haro, Universidad Autónoma de Zacatecas, México.

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