Download as PDF, PPTX
More Related Content
Similar to Joe Kelleher Presentation (May 27th 2014)
Joe Kelleher Presentation (May 27th 2014)
- 1. Using neutrons for in-‐situ observation of engineering material behaviour Joe Kelleher Instrument Scientist, ENGIN-‐X beamline, ISIS
- 2. Neutrons at ISIS H-‐ ion accelerator Proton (H+ ion) synchrotron Second target station First target station Engin-‐X beamline IMAT beamline
- 3. The ENGIN-‐X beamline Incident beam South detector bank North detector bank
- 4. Engin-‐X layout Radial collimator (defines outgoingbeam size) Incident slits Strain direction (bank 1) Diffraction detector (bank 1) Diffraction detector (bank 2) Strain direction (bank 2)45º 45º Sample on translation / rotation table Strain direction (transmission detector) Time of flight 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 16 18 20 22 24 26 28 β-Sn powder Totalcrosssection(barns) Neutron wavelength (Å) Experiment Calculation Transmission detector
- 5. Types of experiment: trends from 1999 to 2011 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 1999 (PEARL) 2002 2005 2008 2011 Strain scanning: welds Strain scanning: other In-situ loading, room temperature In-situ loading, high temperature Other in-situ processes Physics of neutron measurement In-situ loading, cryo- temperature Shareofuserexperimenttime
- 6. From materials to processes Magnetic fields Electrochemical reactions Mechanical deformation Heat treatment Phase transformations Welding Fuel cells Corrosion Shape memory alloys Material forming
- 7. Stressrig (up to 100kN) Cryostat Down to -‐200C Optical furnace Up to 1100C Resistance furnace (small samples, up to ~1600C) Sample environments for in-‐ situ tests Ceramic heating pads (larger samples)
- 8. In-‐situ heat treatment Linear weld Ni superalloy Circumferential pipe weld Single crystal Ni superalloy Anna Paradowska demonstrates proof of principle James Rolph et al. Comptes Rendus Physique 13(3):307– 15. (2012) Bo Chen et al. Acta Materialia submitted (2013) See γ’ misfit as function of temperature
- 9. In-‐situ heat treatment of pipe weld 2.865 2.87 2.875 2.88 2.885 2.89 2.895 2.9 0 200 400 600 800 Atomic la*ce spacing / Å Temperature / °C Weld... Stress-‐free reference... Hea8ng Hea8ng Cooling Cooling Bo Chen, Alexandros Skouras, Yiqiang Wang, Joe Kelleher, Shu Yan Zhang, David Smith, Peter Flewitt, Martyn Pavier
- 10. Cyclic voltage on PZT ferroelectric 100 MPa applied Zero load The MANTID platform § Data reduction and visualisation for all ISIS instruments § Supports event mode and stroboscopic data David Hall, 2013 Loading direction Transverse direction 500 V / mm AC electric field Cyclic electric field causes straining of poled PZT, but applied load depoles the PZT Plots show difference between + and – half-‐cycles – +
- 11.
- 12.
- 13. Practical considerations • Sample environment – Sufficiently non-‐interacting with neutron beam – ‘Contains’ the process for steady-‐state, safety • Timing for dynamic effects – Synchronise clocks or use trigger pulses – Get event mode acquisition to collect other data • Can we record more than just the neutron data?
- 14. Supplementary analytical methods Things that might change in a process • Mechanical deformation, stress and strain • Material ‘damage’ • Phase changes • Diffusion • Temperature Methods that might reveal these changes • Image correlation • Acoustic emission • Thermoelastography • Dilatometry • Calorimetry • Ultrasonic and magnetic methods • Sometimes possible to measure these ‘for free’ with existing sensors
- 15. Full-‐spectrum imaging • Neutron detectors not intrinsically sensitive to wavelength, but to time of detection – …hence velocity, hence wavelength • Each pixel of a 2D detector can record a full wavelength spectrum • We can thus see both spatial and temporal variation in several physical parameters
- 16. Time-‐of-‐Klight neutron imaging for in-‐situ studies Bragg edges show crystal structure – how those atoms are arranged Resonance peaks show which atoms/ isotopes present Wavelength Detected intensity Height → Texture Height → Concentration Width → Temperature Position → Strain
- 17. Steven Peetermans & Joe Kelleher (2013) 17 Transmission spectrum from single crystal Σabs+Σinc+Σinel,coh Σel,coh Position = Orientation and strain Width = Mosaicity
- 18. Conclusion: Some future directions? • Broader array of sensing and actuation on beamlines – Users won’t need to bring their own • Flexible data chopping with event mode – Especially cyclic or highly dynamic processes • Sensor / actuator bus for real time measurement and control (e.g. CANBUS for vehicles)