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| Abstract No.: |
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Scheduled at:
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Thursday, September 29, 2011, Saal A 2:00 PM
Aviation Industry 4
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| Title: |
Highly durable thermal barrier coatings produced by axial suspension plasma spray
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| Authors: |
Zhaolin Tang* / Northwest Mettech Corp., Canada
Doug Ellsworth / Northwest Mettech Corp., Canada
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| Abstract: |
Ceramic Thermal Barrier Coatings (TBCs) on superalloy components are being used successfully in land-based gas turbine and aircraft engines. These coatings are primarily made by either air plasma spraying (APS) or electron beam physical vapor deposition (EB-PVD). In General, EB-PVD TBCs have superior durability due to columnar structure in nature, but they are very expensive compared to APS TBCs. EB-PVD TBCs are used primarily in the most severe applications such as turbine blades and vanes in aircraft engines, but not yet cost-effective for large land-based gas turbine components. This paper presents an economical process to make highly durable TBCs, called Axial Suspension Plasma Spray (ASPS). This technology combines Mettechs axial injection plasma process and automatic slurry feed system. The resulting TBCs exhibited columnar structure with vertical cracks, similar to EB-PVD coatings. Such structures allow the TBC to compensate for thermal expansion differences between it and the base material, resulting excellent durability. A few millimeter thick coatings can be readily deposited using ASPS. The manufacturing cost is expected to be a little more expensive than APS coatings, but much lower that EB-PVD coatings. The ASPS process presents significant potential to replace EB-PVD for aircraft turbines, and offers an economical method to deposit thick TBCs for large land-based turbine components.
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