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| Abstract No.: |
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Scheduled at:
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Friday, May 23, 2014, Hall H2 12:20 PM
Tribological Coatings
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| Title: |
Effects of feedstock shape on the qualities of cold sprayed Cu coatings
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| Authors: |
Jun Oh Choi* / Ajou University, Republic of Korea
K.H. Ko / Ajou university, South Korea
H.S. Lee/ Ajou university, South Korea
H. Lee/ Ajou university, South Korea
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| Abstract: |
Feedstock shape is an important processing parameter during spraying. Two differently shaped (irregular and spherical) Cu powders were used as feedstock, and the differences in shape-dependent coating qualities were analyzed by measuring or observing the deposition efficiency, hardness, stack morphology, and chemical reactivity of the coating. The irregular Cu powders experienced more severe fragmentation than the spherical ones, leading to an increase in the number of small sized particles that accelerated fast enough to overcome the critical threshold velocity required for sticking onto a substrate surface, and in turn, resulting in high deposition efficiency. However, frequent collisions among particles reduced their average amount of kinetic energy thus producing lower plastic deformation and smaller amount of stored energy in the coatings. Thus, the hardness and chemical reactivity of the coatings were decreased even more by using the irregular powder than by using a spherical one.
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