ITSC, the world’s foremost international conference and exposition for thermal spray technologists, researchers, manufacturers and suppliers took place at Long Beach, California, USA on May 11th-14th, 2015. The program featured the latest advanced technology, research and development, and a wealth of resources on thermal and cold spray techniques.
Politecnico di Milano strongly participated with four talks given by Dr. Mostafa Hassani-Gangaraj on the current outcomes of CORSAIR, of which three research works were led by Politecnico di Milano(Prof. M. Guagliano, Dr. A. Moridi and Dr. SM. Hassani-Gangaraj), and one was cooperatively led by Veneto Nanotech (Dr. S. Vezzu and Dr. Rech), King Juan Carlos University (Prof. Pedro Poza) and Politecnico di Milano. The four presentations with a short summary of the results are the following:
Finite element simulation of material jet formation during cold spray deposition of Al and Ti alloys; This work discussed the results of WP2 by describing an effective finite element approach to simulate material jet formation and growth during cold spray of Al2024 and Ti6Al4V. The novel framework led to an accurate estimation of the critical velocity of the two materials of interest, and by extension any other metallic materials.
A damage based finite element simulation of cold spray coating under indentation loading; This work discussed the results of WP2 by describing an experimental effort to characterize the mechanical properties of cold spray coating. A numerical model was also developed to simulate the response of cold spray coating under loading, in general, and indentation, in particular. To this end damage was incorporated for the first time in the modelling of cold spray coating. The model was shown to be able to capture the experimentally observed phenomena such as damage initiation and crack formation in the cold spray coating under extreme loading.
Cold Spray of Al Alloys as Repair Technology in Aeronautics; This work discussed the results of WP5 and design of a new nozzle made of SiC that enables us to explore higher gas temperature deposition in cold spraying Al alloys. Gas temperature was increased in the range of 350-500 C. Different Standoff distances were also examined. The performance of the Al alloy coating was investigated by TCT test, X-ray diffraction, porosity measurements and electron microscopy observations. 500 °C gas temperature combined with 20-50 mm SoD could successfully increase the coating strength to 400 MPa and decrease the prosody to less than 0.5%.
On the Application of Cold Spray Coating in Repairing Damaged Parts: Study of Cavity Filling and Fatigue Behavior; This work discussed the results of WP5 by experimentally assessing the structural integrity of the cold spray coated specimens. One important challenge in using cold spray as a repair technique is retaining the properties of the original material. The fatigue load bearing of the coating is the most important design consideration when structural integrity of the component is concerned. This work experimentally proves that an optimized cold spray process can increase fatigue strength of the coated specimens as compared to the bare substrate.
Heidi Lovelock of TWI presented the development of WP6 and detailed work relating to the optimisation of coatings on Ti-6Al-4V substrates, by the careful control of Ti-6Al-4V powder properties and spraying parameters during her presentation, entitled Effect of Powder Feedstock Properties on Ti-6Al-4V Cold Sprayed Coating Characteristics.