Fraunhofer UMSICHT. Hochtemperaturanwendungen Herausforderungen für Beschichtungstechnologien

Transcription

1 Fraunhofer UMSICHT Institutsteil Sulzbach-Rosenberg Sommersymposium am 27. Juni 2013 Hochtemperaturanwendungen Herausforderungen für Beschichtungstechnologien Dr. HDR Patrick J. Masset

2 Agenda 1. Energy situation 2. Challenges for materials for power engineering 3. Coatings as alternative 4. Conclusion / outlook Folie 2

3 Technologic developments Foto: DIHK Folie 3

4 Evolution of the world population Estimated world population, , and projections: Source: UN World Population to 2300 Folie 4

5 Evolution of the energy needs Global energy demand rises by over one third in the period to 2035, underpinned by rising living standards in China, India & the Middle East Source: OECD/IEA 2012 The combined increase of the individual / industrial needs and population growth leads to high requirements for power engineering within a short time Folie 5

6 Agenda 1. Energy situation 2. Challenges for materials for power engineering 3. Coatings as alternative 4. Conclusion / outlook Folie 6

7 Materials and power engineering Applications Mining Materials processing Production, transport Conversion processes Large variety of raw materials Coal, fuels, biomass, wastes, ores Sun, wind, hydraulic Economy Geographic and geopolitical aspects Cost, availability Folie 7

8 Challenges for coatings for power engineering Costs of corrosion All economic sectors 4% of GDP Consumption of raw materials Safety and environmental issues Combined loads Thermal, chemical, mechanical, radiation Gaseous, liquid, solid phases High temperatures, pressures Folie 8

9 Agenda 1. Energy situation 2. Challenges for materials for power engineering 3. Coatings as alternative 4. Conclusion / outlook Folie 9

10 Why coatings are so interesting? Technologies: electrochemistry, PVD, CVD, thermal spraying, laser cladding Complementary properties to bulk properties Low cost compared to bulk materials (low thickness) Composition and / or properties on request Often reparable Combination of properties (corrosion / wear) molding process light alloys (TiAl) Folie 10

11 Chemical densification of thermal sprayed oxide coatings YSZ 100 µm 100 µm 100 µm NiCr-alloy 0% HCl, 700 C, 3d 4% HCl, 700 C, 3d 2% HCl, 800 C, 1d 100 µm 100 µm 100 µm 2% HCl, 600 C, 3d 2% HCl, 700 C, 3d 2% HCl, 800 C, 3d Densification front from the oxide / alloy interface outwards Densification process depends on temperature and solvo-thermal parameters Folie 11

12 Tribological properties Untreated Treated untreated Friction coefficient µ treated Line scan Cycles Reduction of the friction coefficient Improvement of the tribological properties Folie 12

13 Porosity and hardness Porosity (%) Hardness HV untreated Temperature ( C) untreated Temperature ( C) Decrease of the residual porosity after solvo-thermal post-treatment Increase of the hardness of the coating Folie 13

14 Resistance to mechanical impacts trace of scratch test 200 µm 200 µm Better resistance to impacts, reduced formation of cracks Improvement of the oxide layer cohesion Folie 14

15 Adhesion properties Increase of the adhesion of the Top-Coat to the Bond-Coat Folie 15

16 Resistance to thermal shocks Cycles in liquid Al 4 min in the melt at 800 C 1 min cooling in air till 420 C ZrO 2 on Ni-based bond-coat +solvothermal MgO + Al 2 O 3 -TiO C 800 C 800 C 20 C cer./cer. composite on Ni-based Bond-coat met./cer. composite Steel Cycles Cycles in air 20 min at 800 C 40 min cooling in air till 20 C Improvement of the chemical stability vs. liquid metals Increased resistance against thermal shocks Folie 16

17 TiAl alloys: evidence of environmental embrittlement 100 h, air Accelerated oxidation 5 µm 100h in air at 600 C Accelerated embrittlement 5 µm 100h in air at 900 C Accelerated oxidation of TiAl above 700 C Significant ductility loss (environmental embrittlement) Decrease of mechanical properties (strength) Folie 17

18 Thermal spraying techniques 0 45 µm µm µm µm µm FhG High velocity spraying of molten metallic powder. Powder composition: Ti-51Al-2Cr-2Nb and Ti-54Al-2Cr-2Nb Folie 18 Example of thermal spraying process. Powder size < 45 µm

19 Coated samples MO-CVD PVD HVOF 1 cm Folie 19 Source: Report project IGF-Nr. 24 EBG

20 Coating of industrial components + F Al 2 O 3 Al 2 O 3 TNB + Al-CVD + F oxidised 100 h at 900 C TNB + Al-CVD + F oxidised 50 h at C Blades TNB alloy (as received) TNB + Al-CVD (0.5 1 µm) Oxidation protection up to C + improved mechanical resistance (coating) TiO 2 Applicability of the CVD route on technical parts Al 2 O 3 Untreated blades do not withstand oxidation tests Source: Report project IGF-Nr. 24 EBG Folie 20 TNB + Al-CVD oxidised 100 h at 900 C TNB + Al-CVD oxidised 50 h at C

21 Improvement of the mechanical properties 90 % Goal Higher strength 2 2 Halogen effect Higher ductility 3 no protection Source: Report project IGF-Nr. 24 EBG Folie 21

22 Mechanical properties: overview Source: P. Masset et al, Oral communication, ECS Fall Meeting, Honolulu (Oct. 2012) Folie 22

23 Agenda 1. Energy situation 2. Challenges for materials for power engineering 3. Coatings as alternative 4. Conclusion / outlook Folie 23

24 Conclusion Suitable protection even under complex loads and / or environments Economic benefit Coating development specific to the applications Meet challenges of power engineering Folie 24

25 Outlook Nano-materials Lower thickness of coatings Less materials Specific properties (catalysis) Interdisciplinary approach Combination of technologies Be inspired by other applications / disciplines Versatile technologies Adaptable coatings for different applications Family of coatings Folie 25

26 FRAUNHOFER UMSICHT Institutsteil Sulzbach-Rosenberg Vielen Dank für Ihre Aufmerksamkeit! Thank you for your attention! Merci de votre attention! Kontakt Fraunhofer UMSICHT Fraunhofer-Institut für Umwelt-, Sicherheitsund Energietechnik UMSICHT Institutsteil Sulzbach-Rosenberg Dr. HDR Patrick J. Masset Telefon: Internet: Folie 26