Abradable Coating Development & Testing WP 5.4

Transcription

1 Abradable Coating Development & Testing WP 5.4 Scott Wilson & Team, Sulzer Metco (Switzerland) Oliver De Vriendt, Techspace Aero partners: University Liege, UTBM Belfort, Techspace Aero, Snecma, Sulzer Metco Subcontractor: Sulzer Innotec (incursion testing)

2 GOALS: 1. Abradable coating development for compressor 2. Incursion (rub) testing of abradable against instrumented compressor component blades. Rub management Modelling the abradable and its wearing Development of improved abradable Validation via rub tests

3 Abradable coating development Abradable baseline coating, Metco 601NS. Aluminium 12% silicon alloy + polyester casing abradable shroud blade Can we improve on: incursion cutting behaviour (blade wear & transfer) corrosion resistance

4 Incursion (rub) testing of instrumented components Instrumented rub testing of abradables Validation of rub model Univ. Liege, Techspace Aero, Snecma casing thermocouple probes rub temperature abradable shroud strain gauges incursion of blade into shroud at different rates & tip speeds blade accelerometers rub strain

5 Abradable coating development Candidate abradable coatings Initial corrosion screening (immersion test) Initial Screening criteria Coating Specific Gravity M601NS Organic content 50% No banned elements/metals: Cu, Pb, Cd, Cr VI, Ti, Be, Mg Post- Initial Screening selection: M601NS AlSi-40% polyester reference coating "Alloy 1" low Si Al + 40% polyimide "Alloy 15" - AlSi + 40% stabilised polyester AlSi - 40% fine polyester AlSi - 40% polyester - low matrix porosity (high density spray parameter) ASTM B117 Salt Spray test screening Abradability incursion testing Erosion testing Final: ASTM B117 Salt Spray testing Tensile Bond tests Component OEM blade Abradability incursion testing (instrumented blades)

6 Abradable coating development Initial Screening criteria Coating Specific Gravity M601NS Organic content 50% No banned elements/metals: Cu, Pb, Cd, Cr VI, Ti, Be, Mg Challenges: Limited to Al alloys Cannot use 100% polymeric or rubber materials Eliminated Metco 610NS (Cu content): Al bronze + polymer abradable Corrosion resistance >>> Metco 601NS Al Al e - Galvanic coupling: dominant corrosion mechanism in salt spray environment, particularly for stainless steel substrates. Overrides Al alloy variations. began to experiment with barrier systems Al alloy matrix abradable shroud: e.g. stainless steel or Ti alloy

7 Abradable coating development M601NS (with standard NiAl bondcoat) after 200h salt spray test M601NS + alumina barrier after 200h salt spray test

8 Abradable coating development Alumina was the best barrier system "Alloy 15" (Al-12Si with stabilised polyester) best combination of abradability & corrosion resistance Alloy 1 (low Si, Al alloy matrix) abradability blade wear higher than M601NS "Alloy 15" + alumina (plasma sprayed) barrier system was final choice "Alloy 15" abradable alumina substrate

9 Abradable coating development final corrosion & bond test screening NEWAC: Tensile Bond tests on as-sprayed and salt-spray tested abradble coatings AS-SPRAYED UTS (PS SI) Coating final selection thin Al 2 O 3 bond coat 250h Salt Spray (coupons cleaned in water)

10 Incursion (rub) testing Sulzer Incursion test facility

11 Incursion (rub) testing: incursion conditions Incursion Rate (µm/s) 500 X X 50 X 5 X Blade tip Speed (m/s)

12 Incursion (rub) testing blade shroud configuration rotor & casing instrumented blade data telemetry unit

13 Incursion (rub) testing shroud wear scar blade tip, slight abrasive wear

14 Incursion (rub) testing shroud wear scar blade tip, slight adhesive transfer of shroud material (Al)

15 Incursion (rub) testing: summary of test results reduced transfer vs. M601NS

16 Incursion (rub) testing: abradable screening test results for comparison (using standard "dummy" Ti alloy blades). Wider range test conditions. reduced wear vs. M601NS reduced transfer vs. M601NS

17 Incursion (rub) testing: strain gauge, accelerometer, temperature data supplied to partners for each test rub temperature rub strain

18 Summary: Abradable development: Improved corrosion using barrier system. Improved abradablility, less blade pick-up & wear Significant challenges given system constraints. Continue efforts with Techspace Aero & Snecma (optimisation). Incursion testing on blade component: successful rub testing of Alloy 15 vs. M601NS data acquisition for modelling efforts