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4784 |
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Thursday, May 12, 2016, Room 3C + 3D 11:40 AM Iron-based Coatings |
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Influence of gas composition on cold gas spray of iron aluminides |
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Nuria Cinca / University of Barcelona, Spain Amadeu Concustell/ Thermal Spray Center (CPT). CMEM. Universitat de Barcelona, SPAIN Sergi Dosta*/ Thermal Spray Center (CPT). CMEM. Universitat de Barcelona, SPAIN Irene G Cano/ Thermal Spray Center (CPT). CMEM. Universitat de Barcelona, SPAIN Josep M Guilemany/ Thermal Spray Center (CPT). CMEM. Universitat de Barcelona, SPAIN |
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Very few previous studies have proved the feasibility of cold gas spraying (CGS) of ordered Fe40Al intermetallics. These are a kind of alloys that are being proposed for high temperature applications and whose deposition by CGS is not so straightforward due to their yield strength anomalous behavior at high temperatures. Some attempts with the Kinetics 8000-X system and nitrogen as process gas, resulted in very dense coatings and evidenced the critical influence on the several process and powder parameters. This unusually high sensitivity is explained by the rise of material strength with increasing temperature, an effect that is strongly enhanced by higher strain rates. This is affecting the mechanical properties of not only the impinging particles, but also the previous deposited material, thus making it difficult to build up the coatings. For that achievement, very high-end parameters were necessary. Here we evidence that similar results can be obtained by using a Kinetics 4000 with Helium-Nitrogen mixtures, which allows the achievement of higher impact velocities without the necessity to go to so high energetic conditions which may be detrimental for the equipment. |