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| Abstract No.: |
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Scheduled at:
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Tuesday, May 04, 2010, Hullet Room 3:40 PM
Cold Spraying 4
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| Title: |
Effects of nanosize particles on the intermetallic compound formations of cold sprayed coatings
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| Authors: |
H. Lee* / Ajou University, South Korea
J.O. Choi / Ajou University, Korea
K.H. Ko/ Ajou University, Korea
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| Abstract: |
Comparative studies on the intermetallic compound (IMC) formations of nano- and micro-size Sn incorporated into composite cold gas dynamic sprayed (CGDS, or Cold Spray) coatings were carried out. High purity pure nano (average 150 nm) and micro (under 45 µm) Sn were selected and prepared as raw materials in the forms of as-received or Sn-Ni (agglomerated 3 µm) mixture in order to be sprayed onto Ni and Cu plate-shape substrates. The particles were accelerated by pressurized air with the pressure of 0.7 ~ 2.0 MPa (prior to enter) and 330 oC of nozzle inlet temperature. Post-annealings were done in air and N2 atmospheres for 4 hrs. Both nano- and micro-size Sn particles have been successfully coated at low gas pressure condition in many practices. In spite of original raw composition of Sn-Ni composite were kept as 1:1, there were major particles consisting matrix of coating and they were changed depending on the relative size of Sn; small Ni particles in case of micro Sn-Ni composite, and nanosize Sn for the nano Sn-Ni case. Surprisingly, after post-annealing, microsize Sn formed richer IMC with Ni than nanosize Sn although more intensive reactivity and larger interfacial area were expected in case of nano Sn-Ni composite coatings. Also, there were significant differences in the size and distribution of eutectic pores as well.
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