Issue 22

H. Singh et alii, Frattura ed Integrità Strutturale, 22 (2012) 69-84; DOI: 10.3221/IGF-ESIS.22.08 72 1970 -1980: In the late 1980s, Alkhimov, Anatoli Papyrin and their team at Institute of Theoretical and Applied Mechanics of the Siberian Division of the Russian Academy of Science (ITAM of RAS) in Novosibirisk, developed a "method of applying coating", by converting the wind tunnel experiments into a viable coating technique and patented it. 1990-2000:  A U.S. government sponsored collaborative research and development agreement (CRADA) under the National Center for Manufacturing Sciences (NCMS) brought cold spray out of Russia. Under this CRADA, Anatoli Papyrin, the leader of the cold spray group in Russia, moved to the U.S., built a system at NCMS, and carried out basic studies. Albert Kay, ASB Industries, visited NCMS and bought the license to build cold spray systems and use them for supplying industrial coatings.  Heinrich Kreye, German Armed Forces University, Hamburg, did a large and exhaustive study on all aspects of the cold spray process, including theory, modeling, design and development of guns and nozzles, preparation and characterization of coatings, and development of application coatings. German Aerospace Industry (EADS) also initiated cold spray research directed towards both protective coatings and fabrication of bulk forms. So, during this period the cold spray process developed into an engineered coating process and modeling studies were taken up and various diagnostic techniques were developed to understand and enhance performance of this process. Systematic spray optimization experiments were executed to produce and characterize various coating materials. 2000- 2006: Germany realized that the availability of a reliable cold spray system to produce reproducible coatings was of paramount importance and that cold spray system development is a multi-disciplinary one. Hence, they formed a consortium of Federal Armed Forces University, Hamburg; Linde R & D; and CGT Technologies to pool their respective specialties in materials science, gas technology and process control equipment to evolve the Kinetic 3000 cold spray system. A large number of spray experiments were carried out, which resulted in many industrial applications including the world's first mass production application of the cold spray process, viz., thermal management layers on high performance heat sinks. 2006- Present: At the present time the Cold Spray method is recognized by world leading scientists and specialists. A wide spectrum of research is being conducted at many research centres and companies in many countries and it has been established as a viable coating process to produce protective coatings, performance enhancing layers, ultra- thick coatings, freeforms, and near net shapes. Governments of various countries have realized the importance of this technology and various projects are sanctioned to commercialize this technology. Recent study concentrate on optimizing cold spray parameters to produce coatings of many materials with desired microstructures. Figure 3 : Comparison between different thermal spraying processes[30].