Rosa M. Miranda is Associate Professor with Habilitation in the Mechanical and Industrial Engineering Department, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Portugal, and previously Assessor of the Research and Development Department at the Portuguese Welding and Quality institute, 1982-1999. Rosa is the author of more than 200 publications in Materials processing technologies, welding and materials science.Joao Pedro Gandra is a PhD student in mechanical engineering, researching friction surfacing.Pedro Vilaça is Assistant Professor at the Mechanical Engineering Department of the Lisbon Technical University, and author of more than 150 publications with particular expertise in friction stir welding and processing.Luisa Quintino is Associate Professor with Habilitation in Welding at the Mechanical Engineering Department of the Lisbon Technical University, and author of more than 250 publications, with particular expertise in welding. Previously Luisa was Vice President of IIW, and Chief Executive of the European Welding Federation.Telmo G. Santos is Assistant Professor at the Mechanical Engineering Department of Nova University, and author of several publications, with particular expertise in non destructive testing and friction stir welding and processing.