Microstructural analysis and high temperature creep of Mo-9Si-8B alloys with Al and Ge additions

Transcription

1 Engineering Conferences International ECI Digital Archives Beyond Nickel-Based Superalloys II Proceedings Microstructural analysis and high temperature creep of Mo-9Si-8B alloys with Al and Ge additions Peter Kellner Metals and Alloys, University Bayreuth, Rainer Völkl Metals and Alloys, University Bayreuth Uwe Glatzel Metals and Alloys, University Bayreuth Follow this and additional works at: Part of the Engineering Commons Recommended Citation Peter Kellner, Rainer Völkl, and Uwe Glatzel, "Microstructural analysis and high temperature creep of Mo-9Si-8B alloys with Al and Ge additions" in "Beyond Nickel-Based Superalloys II", Chair: Dr Howard J. Stone, University of Cambridge, United Kingdom Co- Chairs: Prof Bernard P. Bewlay, General Electric Global Research, USA Prof Lesley A. Cornish, University of the Witwatersrand, South Africa Eds, ECI Symposium Series, (2016). This Abstract and Presentation is brought to you for free and open access by the Proceedings at ECI Digital Archives. It has been accepted for inclusion in Beyond Nickel-Based Superalloys II by an authorized administrator of ECI Digital Archives. For more information, please contact

2 Microstructural Analysis and High Temperature Creep of Mo-9Si-8B Alloys with Al and Ge Additions Peter Kellner, Rainer Völkl, Uwe Glatzel Metals and Alloys, University Bayreuth University Bayreuth

3 Content Mo-9Si-8B-xAl-yGe Argon arc melting Microstructural characterization Tensile creep testing Summary and outlook University Bayreuth 2

4 Mo-9Si-8B-xAl-yGe Alloys: Mo 9Si 8B xal yge x = 0 2 at. % y = 0 2 at. % Aluminum and Germanium: Al reduces the initial crack density reduce the melting point of the alloy reduces slightly the density of the alloy University Bayreuth 3

5 Powder metallurgy (SPS) Spark Plasma Sintering (SPS) at KIT Vacuum chamber Powder SPS specimen with schematic creep sample Geometry: 10 mm 100 g ; ρ = 9.1 g/cm 3 40 mm Graphite 1650 C/ 50 MPa/ 15 min 10 mm University Bayreuth 4

6 Melting metallurgy pure elements arc melting B heat treatment 1850 C for 24 h creep specimen Al Mo 2 mm Si Ge University Bayreuth 5

7 Melting metallurgy pure elements arc melting heat treatment 1850 C for 24 h Arc melting furnace creep specimen University Bayreuth 6

8 Melting metallurgy pure elements Arc melting process arc melting heat treatment 10 mm 1850 C for 24 h creep specimen 50 μm University Bayreuth 7

9 Melting metallurgy pure elements arc melting heat treatment 1850 C for 24 h Vacuum cold wall furnace creep specimen University Bayreuth 8

10 Melting metallurgy pure elements Arc melted specimen with schematic creep sample arc melting heat treatment 1850 C for 24 h 30 g ; ρ = 9.3 g/cm 3 10 mm creep specimen University Bayreuth 9

11 Mo-9Si-8B-2Al Mo ss Mo 3 Si Mo 5 SiB 2 nominal Mo 5 SiB 2 composition Mo Si Heat treatment: 1850 C 24 h Mo Si = μm B n. d. n. d. n. d Al Stated in at.% University Bayreuth 10

12 Mo-9Si-8B-2Al Mo ss Mo 3 Si Mo 5 SiB 2 theo. composition 55% 15% 30% Mo-9Si-8B (SPS) [1] 57% 14% 29% Mo-9Si-8B-2Al 56% 22% 22% Heat treatment: 1850 C 24 h 50 μm [1] C. Hochmuth, 2014, Intermetallics 48 University Bayreuth 11

13 28 mm Creep testing device temperatures up to 1500 C vacuum Pa Specimen geometry small specimens 5 mm University Bayreuth 12

14 Creep tests 1 mm University Bayreuth 13

15 SPS creep tests University Bayreuth 14

16 Arc melted creep tests Arc melted specimen: test time in total over 1000 h no strain rate detected for 50 MPa after more than 150 h University Bayreuth 15

17 Creep tests [1] doubling the grain size decreases the minimum strain rate one order of magnitude University Bayreuth 16 [1] C. Hochmuth, 2014, Intermetallics 48

18 Summary and outlook successfully adapted the way of manufacturing microstructural characterization with EDS, XRD and XRF new creep testing device creep test FIB tomography microstructural characterization after creep testing University Bayreuth 17

19 Thank you for your attention Mo-9Si-8B-2Al: 1250 C 250 MPa 150 h University Bayreuth 18

20 University Bayreuth 19