Special Issue Celebrating Professor Terence G. Langdon's 80th Birthday

This special issue is dedicated to the celebration of Prof. Terence G. Langdon's 80th birthday. He is currently the William E. Leonhard Professor of Engineering Emeritus at the University of Southern California (USC) in USA and Professor of Mechanical Engineering at the University of Southampton in UK. Professor Langdon was born and educated in the West Country in south-western England. He received a B.Sc. degree in Physics from the University of Bristol in 1961 and a Ph.D. degree in Physical Metallurgy from Imperial College, University of London, in 1965. Following post-doctoral appointments at the University of California at Berkeley, the University of Cambridge and the University of British Columbia, he was appointed Associate Professor of Materials Science and Mechanical Engineering at the University of Southern California in 1971. He was promoted to Professor in 1976 and in 2003 he was appointed the William E. Leonhard Professor of Engineering. At USC he served as a member of three departments: Aerospace and Mechanical Engineering, Chemical Engineering and Materials Science, and Earth Sciences. He retired from USC in 2012 and was then appointed Professor of Materials Science in the School of Engineering and Physical Sciences at the University of Southampton in the UK. One of the main points of Professor Langdon's career has been his ability to share experiences and knowledge with international research groups. As an amateur radio enthusiast (call-sign G3MHV) and active traveler, he displays a unique ability to interact with different cultures. An example of the synergy between his interest for international collaborations and keenness to travel is the visits to Russia in the 1990s where Prof. Langdon made an effort to travel, together with his wife, Mady, also an amateur radio enthusiast (call-signs KP3YL and G4WHV), to different locations in Russia all the way to Vladivostok. During this time they visited the region of Tuva at the geographic center of Asia and this was later featured in a magazine article titled “A Journey to the Center of Asia” that was written for amateur radio operators.1 In practice, Prof. Langdon's contacts with researchers in Ufa, and especially the research group of Professor Ruslan Z. Valiev, played a key role in the development of the research field of nanostructured materials processed by severe plastic deformation (SPD). Prof. Langdon's contribution to the development of NanoSPD will be recognized by holding a special workshop on “Restructuring of Materials for Advanced Applications to Celebrate the 30th Anniversary of Prof. Langdon's First Journey to Ufa” at Nanjing University of Science & Technology, China, on 21–22 March, 2020. Prof. Langdon has demonstrated a willingness to organize and participate in research meetings and conferences in any location. He has also actively engaged in longer academic activities in Universities and Research Institutes around the world. He was appointed Visiting Professor or Researcher in the Department of Metallurgy, University of Melbourne, Australia (1977–78), Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de Mexico, Mexico City, Mexico (1981), Metallurgy Department, Risø National Laboratory, Roskilde, Denmark (1984), Dipartimento di Meccanica, Universita degli Studi di Ancona, Italy (1992), International Center for Advanced Studies, Nizhny Novgorod, Russia (1997), Department of Physics, Danish Technical University, Lyngby, Denmark (1998), Department of Materials Science and Engineering, Kyushu University, Fukuoka, Japan (2001), Department of Metallurgy and Materials Engineering, University of Tehran, Iran (2011), Warsaw University of Technology, Warsaw, Poland (2014), Kuwait College of Technological Studies, Kuwait (2014), Federal University of Minas Gerais, Belo Horizonte, Brazil (2015), Beijing Institute of Technology, China (2018), and Harbin Institute of Technology, China (2019). In addition, Prof. Langdon has been elected a member/fellow of several prestigious academic societies: a Foreign Member of The Academy of Sciences of the Bashkortostan Republic, Russian Federation, in 1994, a Fellow of the Royal Academy of Engineering in 2002, a Fellow of the European Academy of Sciences in 2008, and a Member of Academia Europaea in 2014. He received the degrees of Doctor honoris causa from The Russian Academy of Sciences in 2003 and Peter the Great St. Petersburg Polytechnic University in 2016. He has also received numerous awards including the Henry Marion Howe Medal from ASM International in 2000, the Sōmiya Award from the International Union of Materials Research Societies in 2005, the Albert Sauveur Achievement Award from ASM International in 2007, the Blaise Pascal Medal in Material Science from the European Academy of Sciences in 2008, the Lee Hsun Award and Lecture from the Chinese Academy of Sciences in 2009, the Honorary Medal “De Scientia et Humanitate Optime Meritis” from the Academy of Sciences of the Czech Republic in 2009, the Acta Materialia Gold Medal from the Acta Materialia Board of Governors in 2012, the State Prize in Science and Technology of the Republic of Bashkortostan, Russian Federation, in 2015, and the Oleg D. Sherby Award from TMS in 2018. Professor Langdon's scientific achievements have been well recognized in the Materials Science community from his earlier work on creep and superplasticity to his more recent investigations on ultrafine-grained (UFG) materials processed by SPD. His research accomplishments and significant contributions to the Materials Science community led to a special symposium titled The Langdon Symposium: Flow and Forming of Crystalline Materials honoring Prof. Langdon on the occasion of his 65th birthday as part of the 2005 TMS Spring Meeting held in San Francisco on 13–16 February, 2005.2 The preface to that meeting called attention to the large numbers of papers he had published, over 600 in 2005, and noted an interesting statistic: the initials of the last names of his many collaborators in these papers covered all 26 letters of the alphabet. However, there was only one collaborator with letter J and only one with letter Q and this left room for improvement according to the authors.3 It is apparent his endless enthusiasm for scientific activities has increased with time. Thus, as of early November 2019, the total number of his publications has increased to over 1100 which is almost two times the number in 2005. The impact of these contributions are clear because he has received a total of more than 75 000 citations with an h-index of 131 on Google Scholar. These papers have been co-authored by ≈800 different researchers from ≈300 institutions in ≈40 countries according to Web of Science. It is worth mentioning that the number of collaborators with last name initials of Q and J has increased to 4 and 17, respectively, in the last 15 years! For more than half a century, numerous numbers of M.S. students, Ph.D. students, postdocs, and visiting scholars from all over the world have enjoyed performing Materials Science research in Prof. Langdon's laboratories at USC and the University of Southampton. Moreover, he has collaborated actively with a significant number of the world's leading scientists. Accordingly, many of these graduates, co-workers, and colleagues now celebrate this special occasion of Prof. Langdon's 80th birthday by presenting their latest research results and we have gathered a total of 35 review and research articles in this special issue of Advanced Engineering Materials. This special issue focuses on all aspects of the deformation of materials including creep and superplasticity, UFG metals and materials and their enhanced properties, and SPD processes and advanced manufacturing techniques. To initiate this special issue, Prof. Langdon kindly summarized several important research highlights in the areas of creep, superplasticity, and UFG materials that were investigated over a period of more than 50 years of his research life. Including his article, a total of 35 contribution reports are reasonably categorized in the following eight exciting areas which provide a good representation of many of the current urgent topics in modern materials science. Table 1 shows a list of the eight topics with information on the 35 contributed articles and the leading authors. As the guest editors, we would like to acknowledge all authors that contributed to this special issue for their dedication, timeliness, and cooperation. We would also like to extend our special thanks to the editor-in-chief of Advanced Engineering Materials, Dr. Sandra Kalveram, for her kind assistance which contributed to the success of this special issue. Lastly, on behalf of all the contributors to this special issue, we would like to wish Professor Terence G. Langdon a very happy 80th birthday and all the best for many years to come.