Advanced High Temperature Alloys

Advanced High Temperature Alloys
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Published Date:21-07-2017
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Advanced High Temperature Alloys Prof. Dr.-Ing. Uwe Glatzel Metals and Alloys University Bayreuth SS 2015 1 University Bayreuth, Advanced High Temperature Alloys Uwe Glatzel, Metals and AlloysLecturer: Prof. Dr.-Ing. habil. Uwe Glatzel • born Dez. 1960 • Physik-Diplom (B.Sc. and M.Sc) in Tübingen (exchange year in Corvallis, Oregon, USA) • PhD thesis at the Institute for Metals Research, Technical University Berlin, Prof. Monika Feller-Kniepmeier • post-doc (1 Jahr) at Stanford University • Habilitation TU-Berlin • Gerhard-Hess award of the German Science Foundation (DFG) for young scientist (400.000 €) • 1996-2003 full professor for Metals and Alloys, Jena • since April 2003 Bayreuth (Chair for Metals and Alloys) postal address: Ludwig-Thoma-Str. 36b phone: +49 (0) 921 - 55-5555 D-95447 Bayreuth, Germany e-mail: uwe.glatzeluni-bayreuth.de 2 University Bayreuth, Advanced High Temperature Alloys Uwe Glatzel, Metals and AlloysLiterature • R. Bürgel, Handbuch Hochtemperatur-Werkstofftechnik, Vieweg • R.C. Reed, The Superalloys - Fundamentals and Applications, Cambridge Univ. Press • M.J. Donachie, S.J. Donachie, Superalloys - A Technical Guide, ASM International • H. Frost, M.F. Ashby, Deformation-Mechanism Maps, Pergamon Press • M.F. Ashby, Materials Selection in Mechanical Design, Elsevier • G. Meetham, M. Van der Voorde, Materials for High Temperature Engineering Applications, Springer • J. Betten, Creep Mechanics, Springer • R.E. Reed-Hill, Physical Metallurgy Principles, PWS-KENT Publishing • D.R. Askeland: Materialwissenschaften, Spektrum Lehrbuch; 1994 • W.D. Callister: Materials Science and Engineering - An Introduction, Wiley, New York, 1999 • H. Schumann, Metallographie, Deutscher Verlag für Grundstoffindustrie, Leipzig • F. Vollertsen, S. Vogler, Werkstoffeigenschaften und Mikrostruktur, Hauser Verlag • P. Haasen, Physikalische Metallkunde, Springer-Verlag, Berlin • H.-J. Bargel, G. Schulze, Werkstoffkunde, VDI-Verlag, Düsseldorf • P. Sarrazin, A. Galerie, J. Fouletier, Mechanisms of High Temperature Corrosion, Trans. Tech. Publ. •N. Cumpsty, Jet Propulsion, Cambridge Univ. Press lecture notes: http://www.metalle.uni-bayreuth.de then "Lehre" then "Vorlesungen", you will find the link to this lecture notes and three review talks we will do at the end. 3 University Bayreuth, Advanced High Temperature Alloys Uwe Glatzel, Metals and AlloysWhat You Should Know: • basic thermodynamics • introduction to diffusion • introduction to dislocations • phase diagrams • theory of elasticity • ... • basic materials science courses 4 University Bayreuth, Advanced High Temperature Alloys Uwe Glatzel, Metals and AlloysContent 1. Introduction, Basics 2. Stability of Microstructure 3. Mechanical Properties a) Static b) Cyclic (Fatigue) 4. High Temperature Corrosion 5. High Temperature Alloys 6. Lost Wax Investment Casting 7. Depending on Time: Lectures on a) SX Ni-Base Superalloys b) LEK 94 c) Pt-Base Superalloys 5 University Bayreuth, Advanced High Temperature Alloys Uwe Glatzel, Metals and AlloysIntroduction • only alloys will be looked at (no ceramics, no polymers). • no coatings (BUT : practically all high temperature systems are coated), simply not enough time. 6 University Bayreuth, Advanced High Temperature Alloys Uwe Glatzel, Metals and AlloysMotivation for High Temperature Alloys T T max min η • efficiency of Carnot heat enging T max (with hot and cold temperatures). Several research projects related to jet engines, stationary gas turbines and waste-to-energy plant are carried out within my group with the goal to increase T . max • melting processes (glass, metal, ... ). • chemical process (PTFE, ... ). • many other applications ... • jet engines, see Single Crystal Ni-Base Superalloys 7 University Bayreuth, Advanced High Temperature Alloys Uwe Glatzel, Metals and AlloysMaximum Temperatures for Applications of Different Materials maximum service temperature Group deformation/damage mechanism °C Polymer up to 300 melting, decomposing (pyrolyze) Glass up to 800 viscous flow Fe-Basis (coated) up to 1100 Fe-ODS up to 1300 Ni- and Co-base up to 1200 creep, dislocation climb, Metals Pt-base up to 1600 grain boundary sliding refractory metals in inert atmosphere above 1600 MoSi up to 1800 2 viscous flow, glass transition Ceramics SiC up to 1600 temperature, grain boundary sliding Composits (SiC/C) up to 1600 complex 8 University Bayreuth, Advanced High Temperature Alloys Uwe Glatzel, Metals and AlloysOverview Materials source: Plansee AG, Reutte, Tirol, Austria 500 1500 2000 temperature °C 9 University Bayreuth, Advanced High Temperature Alloys Uwe Glatzel, Metals and Alloys usable strengthTaking Density into Account 500 1500 2000 temperature °C 10 University Bayreuth, Advanced High Temperature Alloys Uwe Glatzel, Metals and Alloys usable strengthOxidation Resistance 500 1500 2000 temperature °C 11 University Bayreuth, Advanced High Temperature Alloys Uwe Glatzel, Metals and Alloys usable strengthRefractory Metals: wider definition Most common definition of of refractory metals (refractory = refractory metals widerspenstig, halsstarrig): two elements of the 5. and three elements of the 6. period with melting points higher than Pt. Processing in general T of platinum m by powder metallurgy. 12 University Bayreuth, Advanced High Temperature Alloys Uwe Glatzel, Metals and AlloysDensity Os, Ir Pt Re W Au Ta Hf Ru, Rh, Pd Tc Pd Mo Ag Nb Ni 13 University Bayreuth, Advanced High Temperature Alloys Uwe Glatzel, Metals and AlloysAbundance of Elements in Earth's Upper Continental Crust to find 1 Rh atom within a bunch of Si-atoms is comparable to find one individual person within the word population © U.S. Geological Survey Fact Sheet 087-02 (2002) 14 University Bayreuth, Advanced High Temperature Alloys Uwe Glatzel, Metals and AlloysMaterial Choice • temperature • environment • moving/non-moving part • design complexity (how to manufacture) • price constrictions (depending on application of system). Reduction of 1 kg in weight: – car 0 - 5 € – plane 100 – 500 € – aerospace 100.000 - 500.000 € 15 University Bayreuth, Advanced High Temperature Alloys Uwe Glatzel, Metals and AlloysInfluence of ... on ... • temperature: – phase transitions, volume fractions, ... – diffusion ( recrystallization, dislocation climb, diffusional creep, ... ) – thermal fatigue (TF) • mechanical: – creep – fatigue (low cycle, LCF, high cycle fatigue, HCF) • environment: – oxidation – corrosion • combinations: – thermo-mechanical fatigue (TMF) – stress corrosion cracking, stress oxidation, ... 16 University Bayreuth, Advanced High Temperature Alloys Uwe Glatzel, Metals and AlloysBasics Thermodynamics ↔ Kinetics Boltzmann-statistics: energy of movement increases with temperature 3 u  kT kin B atom 2 3 Q u 2 u 2 kT 3kT  total kin B B atom atom RT 2  e 0  0,33 eV, bzw. 32 kJ/mol bei 1000°C Arrhenius-plot U 3 RT total mol 17 University Bayreuth, Advanced High Temperature Alloys Uwe Glatzel, Metals and AlloysVacancy Concentration F = U - T·S  non-zero vacancy concentration is in thermodynamic equilibrium Q vac  nickel Q = 1,36 eV (energy necessary to create one vacancy) RT vac c e v T°C 20 300 450 800 1000 1200 1454 T/T 0.17 0.33 0.42 0.62 0.74 0.85 1.00 m -23 -12 -9 -6 -5 -5 -4 c 10 3·10 10 10 10 7·10 3·10 v equilibrium vacancy concentration for nickel 18 University Bayreuth, Advanced High Temperature Alloys Uwe Glatzel, Metals and AlloysNickel Vacancy Concentration Q vac  0 kT 10 B c e v T /2 m -5 10 with: nickel -10 Q = 1,36 eV 10 vac -5 k = 8.60210 eV/K B -15 10 1,00 -20 10 0,75 Nickel Vacancy Concentration Nickel Vacancy Concentration 0,50 -25 10 0,25 0 200 400 600 800 1000 1200 1400 1600 0,10 T m temperature °C 0 200 400 600 800 1000 1200 1400 1600 T m temperature °C 19 University Bayreuth, Advanced High Temperature Alloys Uwe Glatzel, Metals and Alloys vacancy concentration -4 vacancy concentration 10 Diffusion  jDc 1. Fick's law -2 -1 j = (atoms) · m · s 2 -1 D = m · s -3 c = (atoms) · m vacancy diffusion or volume diffusion 20 University Bayreuth, Advanced High Temperature Alloys Uwe Glatzel, Metals and Alloys