Full Record for Micrograph 727
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- Micrograph no
- Brief description
- Ni-Superalloy, heat treated above gamma-prime solvus
- Metal or alloy
- Ni, Cr 14.4-15.2, Co 13-18, Mo 3.5-4.5, Al 3.0-3.3, Ti 4.2-4.8, Ta 2.5, Zr 0.05-0.07, C 0.05, B 0.01-0.03 (wt%) (Ni-Superalloy)
- Standard codes
- Heat treated at 1200ÂºC for one hour, forced air cool.
- Discs are used for high pressure and intermediate pressure turbine discs in Trent 800/900 series gas turbine engines.
- Sample preparation
- Ground to 4000 Grade SiC paper and then polished at 6 <span class="symbol">m</span>m 3 minutes, 1 <span class="symbol">m</span>m 5 minutes, Colloidal silica 10 minutes. Etched using a â€˜Nimonicâ€™ etch which preferentially attacks <span class="symbol">g</span>'.
- Field emission gun scanning electron microscopy (FEGSEM) in secondary electron imaging (SEI) mode
- Length bar
- 100 nm
- Further information
- Micrograph shows a close up of the secondary g' present within the centre of g grains. This form of g' grows with prolonged exposure to temperature and forms the blocky primary g' found on the grain boundaries.
View schematic diagram of g' microstructure
- R J Mitchell
- Rolls-Royce University Technology Centre, Department of Materials Science and Metallurgy, University of Cambridge
- Licence for re-use
- Attribution-Non-Commercial-Share Alike 2.0 UK: England & Wales
- Related micrographs
- Micrograph 724: Ni-Superalloy, as-extruded microstructure (10 μm)
- Micrograph 725: Ni-Superalloy, as-extruded microstructure (10 μm)
- Micrograph 726: Ni-Superalloy, heat treated above gamma-prime solvus (10 μm)
- Micrograph 728: Ni-Superalloy, heat treated above gamma-prime solvus (10 μm)
- Micrograph 729: Ni-Superalloy, exposed microstructure (10 μm)
- Micrograph 734: Ni-Superalloy, as-extruded microstructure (20 μm)