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| Abstract No.: |
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Scheduled at:
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Wednesday, June 04, 2008, Room 04 2:00 PM
Gasturbines 5
Coatings for mobile and stationary turbines, protection against wear, high temperature corrosion and thermal stresses, clearance control coatings for a better efficiency
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| Title: |
Comparison of a new high-purity HOSP? PYSZ powder with standard HOSP:
powder/coating characterization and thermal shock testing
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| Authors: |
Kenneth Lawson / Cranfield University, UK
Simon Gray* / Cranfield University, UK
Mitchell Dorfman/ Sulzer Metco (US) Inc., USA
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| Abstract: |
A new high-purity HOSP (hollow spherical powder) PYSZ powder has been developed. Four TBC systems (2 standard types and 2 high purity versions) were APS onto CMSX4 substrates with APS CoNiCrAlY bondcoats. Thermal shock testing was performed to 50 % spallation at 1135°C with 1 hour hot cycles with forced air cooling. The powders, as-deposited coatings and those after thermal shock failure were characterised using X-ray diffraction, Raman spectroscopy, scanning electron microscopy and image analysis. The thermal cycling results show little difference in the thermal shock resistance of the coatings with all failing in an adhesive manner with failures occurring in excess of 180 hot cycles. XRD and Raman data is used to identify the levels of monoclinic and tetragonal phases present in each coating and image analysis used to identify differences between the 204-NS and tighter controlled particle size distribution 204B-NS. These data confirm the viability of the high-purity HOSP coatings as next generation coatings.
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