![Oxford Instruments Analytical 2003
Analytical An
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{200}
See the new dedicated EBSD website: http://www.EBSD.com
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![Oxford Instruments Analytical 2003
Analytical An
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=25 µm; E1-3; Step=0.7 µm; Grid200x200
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Inverse Pole Figures
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[Alumin.cpr]
Aluminium (m3m)
Complete data set
40000 data points
Equal Area projection
Upper hemispheres
X0
001
111
101
Y0
Z0
Inverse Pole Figures
(Folded)
[Alumin.cpr]
Aluminium (m3m)
Complete data set
40000 data points
Equal Area projection
Upper hemispheres
Half width:10°
Cluster size:5°
Exp. densities (mud):
Min= 0.00, Max= 5.99
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4
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Introduction to EBSD
- 1. Oxford Instruments Analytical 2003 Analytical An Introduction to EBSD Keith Dicks MSc EBSD Specialist Oxford Instruments Analytical High Wycombe England See the new dedicated EBSD website: http://www.EBSD.com 1/63
- 2. Oxford Instruments Analytical 2003 Analytical An EBSD • Crystallographic Orientations • Misorientations • Texture measurement • Grain size and boundary types • Phases To be characterised and quantified on a macro to sub- micron or nano-meter scale EBSD = Electron Back Scatter Diffraction which allows: See the new dedicated EBSD website: http://www.EBSD.com 2/63
- 3. Oxford Instruments Analytical 2003 Analytical An What does EBSD Contribute to Materials Analysis? • EDS/WDS - Chemical analysis – i.e. What the sample is made from • EBSD - Microstructural analysis – Polycrystalline materials • Grain Structure - size/distribution, ASTM number etc. • Grain Boundary Characteristics • Macro & Micro-Crystallographic Texture • Phase Discrimination and distribution • Deformation – Single Crystal materials/deposited layers • Crystal orientation • Epitaxy between layers – i.e. How the sample is put together and what condition it is in See the new dedicated EBSD website: http://www.EBSD.com 3/63
- 4. Oxford Instruments Analytical 2003 Analytical An Typical Applications • Metals – Metal production i.e. sheet metal, castings, forgings - automotive, aerospace, power generation and distribution, petrochemical and chemical plant, nuclear i.e. extreme duty materials - high strength, high temperature and corrosive environments. Electronics. – Phase identification and discrimination – Texture analysis, grain boundary characterisation – Deformation • Geological – Phase identification and discrimination – Orientation & texture analysis • Ceramics – Phase identification and discrimination – Orientation & texture analysis See the new dedicated EBSD website: http://www.EBSD.com 4/63
- 5. Oxford Instruments Analytical 2003 Analytical An Typical Areas of Investigation • Production and process control – Cost savings - reduce heat treatment times, optimise heat treatment and phase transformation, investigate grain size, grain boundary and texture evolution – Improved product i.e. surface finish, forming or joining characteristics, process optimisation & control – Control physical properties - improve or achieve specific properties i.e. high corrosion resistance, fatigue or cracking (stress corrosion cracking) resistance. • Component life-time prediction – Characterise microstructure - identify problem phases or microstructural feature • Failure Analysis – Investigate micrstructural features associated with failure and propose failure mechanism See the new dedicated EBSD website: http://www.EBSD.com 5/63
- 6. Oxford Instruments Analytical 2003 Analytical An Schematic Layout of EBSD System • Schematic layout of components • PC and Imaging hardware common for INCA Energy and Wave • Market leading EBSD, EDS & WDS all from one vendor See the new dedicated EBSD website: http://www.EBSD.com 6/63
- 7. Oxford Instruments Analytical 2003 Analytical An ‘Nordlys’EBSD Detector See the new dedicated EBSD website: http://www.EBSD.com 7/63
- 8. Oxford Instruments Analytical 2003 Analytical An Comparison of conventional and advanced EBSD hardware design Conventional ‘open bracket’ design Advanced ‘in tube’ design Tube length does not affect efficiency See the new dedicated EBSD website: http://www.EBSD.com
- 9. Oxford Instruments Analytical 2003 Analytical An X-Rays Incident beam Backscatter Diffracted Electrons EBSD hardware - configurable collection geometry Forward Scattered Electrons • Revolutionary high efficiency, fast detector with rectangular phosphor and multiple FSE detectors • Motorized insertion/retraction with no constraints on working geometry • Can be optimised for short WD or to avoid occluding other detectors Camera position control unit See the new dedicated EBSD website: http://www.EBSD.com 8/63
- 10. Oxford Instruments Analytical 2003 Analytical An
- 11. Oxford Instruments Analytical 2003 Analytical An Forward Scattered Electron (FSE) Imaging • FSE greatly enhances diffraction contrast in imaging • Grains and grain boundaries are clearly revealed See the new dedicated EBSD website: http://www.EBSD.com 9/63
- 12. Oxford Instruments Analytical 2003 Analytical An FSE Imaging using a single detector • Nickel • Austenitic Stainless Steel See the new dedicated EBSD website: http://www.EBSD.com 10/63
- 13. Oxford Instruments Analytical 2003 Analytical An Forescatter Detector Option • For orientation, phase contrast imaging at high tilt • Two, four or six diodes – may be retrofitted or moved by user • BSE, FSE or mixed mode detection See the new dedicated EBSD website: http://www.EBSD.com 11/63
- 14. Oxford Instruments Analytical 2003 Analytical An See the new dedicated EBSD website: http://www.EBSD.com 12/63
- 15. Oxford Instruments Analytical 2003 Analytical An BSE Image – Density (phase) contrast OC (FSD) Image – Channeling contrast Multiphase rock (gabbro) See the new dedicated EBSD website: http://www.EBSD.com 13/63
- 16. Oxford Instruments Analytical 2003 Analytical An Calcite (Dave Prior, Liverpool) Forescatter gallery Welded superalloy (NPL) Deformed superalloy 100µm 100µm Plagioclase Zircon grain See the new dedicated EBSD website: http://www.EBSD.com 14/63
- 17. Oxford Instruments Analytical 2003 Analytical An EBSP Formation • The electron beam strikes the specimen • Scattering produces backscatter electrons in all directions, most intensely downward & outward • Electrons that travel along a crystallographic plane trace generate Kikuchi bands whose widths are dictated by the Bragg Law and specimen-to-phosphor screen distance. • The electrons hit the imaging phosphor and produce light • The light is detected by a CCD/SIT camera and converted to an image • Which is indexed... See the new dedicated EBSD website: http://www.EBSD.com 15/63
- 18. Oxford Instruments Analytical 2003 Analytical An Bragg’s Law nλ=2d sinθ Extra path length = 2d sinθ d θ Constructive interference occurs when the extra path length is an integral number of wavelengths. λ = 12.26 ∗ Ε-1/2 E = incident beam energy in volts For 20 kV and a plane spacing of 0.2 nm, the Bragg angle, θ,is about 1.25° . Diffraction
- 19. Oxford Instruments Analytical 2003 Analytical An 70° (202) (022) (220) Silicon Spherical Kikuchi map Phosphor screen EBSP formation See the new dedicated EBSD website: http://www.EBSD.com 16/63
- 20. Oxford Instruments Analytical 2003 Analytical An {100} [100] [010] [011] [001] {110} (011) c b a ! {200} See the new dedicated EBSD website: http://www.EBSD.com 17/63
- 21. Oxford Instruments Analytical 2003 Analytical An What does an EBSP look like? Silicon at 20kV See the new dedicated EBSD website: http://www.EBSD.com 18/63
- 22. Oxford Instruments Analytical 2003 Analytical An Hi-res EBSP - Si 20kV
- 23. Oxford Instruments Analytical 2003 Analytical An From EBSP to Orientation EBSP Hough ‘space’ Hough Peaks found EBSP Bands detected • ‘Matching’ algorithm compares detected bands with those calculated from the crystal structure for the phase(s) of interest • EBSP ‘solved’ or ‘indexed’ to find orientation of crystal under the beam ‘solve’ See the new dedicated EBSD website: http://www.EBSD.com 19/63
- 24. Oxford Instruments Analytical 2003 Analytical An ! " # • List of angular relationships between detected bands • Band positions on phosphor screen • Other information also extracted (e.g. band widths) • Highest intensity bands most likely to be detected Band Detection For each potential phase, list of allowed reflections, diffraction band widths and intensity hierarchy generated from kinematic electron diffraction theory or reflector list is loaded. Also, for reflections above an intensity cutoff, interband angles are calculated. Match? Phase discriminated Orientation determined Reflector Calculation Yes See the new dedicated EBSD website: http://www.EBSD.com 20/63
- 25. Oxford Instruments Analytical 2003 Analytical An Hough transform & band detection Collect EBSP Match to phase & orientation Verify match: Indexed EBSP Phase and orientation Indexing cycle Position beam See the new dedicated EBSD website: http://www.EBSD.com 21/63
- 26. Oxford Instruments Analytical 2003 Analytical An Mapping See the new dedicated EBSD website: http://www.EBSD.com 22/63
- 27. Oxford Instruments Analytical 2003 Analytical An From EBSP to Crystal Orientation Map • COM with Inverse Pole key for cubic material • Red = 100 • Green = 110 • Blue = 111 planes parallel to the surface • Orientation obtained at every pixel • Colour derived from inverse Pole Figure color key or Euler angles • Hough transform for every pixel stored for post acquisition reprocessing See the new dedicated EBSD website: http://www.EBSD.com 23/63
- 28. Oxford Instruments Analytical 2003 Analytical An Factors affecting EBSP Quality Electron Back Scattered Patterns (EBSP’s) vary greatly... See the new dedicated EBSD website: http://www.EBSD.com 24/63
- 29. Oxford Instruments Analytical 2003 Analytical An EBSP ‘Background’ • Only a small proportion of the electrons arriving at the phosphor screen are diffracted. • Therefore the pattern is superimposed on a ‘background’ • Background removal is required to enhance pattern contrast See the new dedicated EBSD website: http://www.EBSD.com 25/63
- 30. Oxford Instruments Analytical 2003 Analytical An Enhancing EBSP Contrast - Background Removal • EBSP contrast enhanced by background subtraction or division • Particularly useful in lighter atomic number materials or when pattern quality (contrast) is low Fe 20kV raw EBSP 70% Background subtracted Background Divided See the new dedicated EBSD website: http://www.EBSD.com 26/63
- 31. Oxford Instruments Analytical 2003 Analytical An Accelerating Voltage - Effect of kV on Pattern Quality • Bands are broader and less sharp at low kV • Band detection can be influenced by Hough parameters Nickel 10kV Nickel 20kV Nickel 30kV See the new dedicated EBSD website: http://www.EBSD.com 27/63
- 32. Oxford Instruments Analytical 2003 Analytical An $ % Sampling selection on fracture surface or free sediment & Operator must search for locations where local topography & damage level allow clear patterns to reach detector • FIB-SEM allows precision selection of areas for sectioning & mapping See the new dedicated EBSD website: http://www.EBSD.com 28/63
- 33. Oxford Instruments Analytical 2003 Analytical An Examples of EBSPs alpha-Fe Al Ge W2Zr Ni Gamma-Fe See the new dedicated EBSD website: http://www.EBSD.com 29/63
- 34. Oxford Instruments Analytical 2003 Analytical An Examples of EBSPs YBa2Cu3O 7 (6kV) BaTiO3 GaP GaSb InP beta-Si3N4 See the new dedicated EBSD website: http://www.EBSD.com 30/63
- 35. Oxford Instruments Analytical 2003 Analytical An Examples of EBSPs Garnet Calcite Olivine Pyroxene Ca3Fe2(SiO4)3 Ca(CO3) Mg2SiO4 MgSiO3 Fe2SiO 4 Fe2NiP See the new dedicated EBSD website: http://www.EBSD.com 31/63
- 36. Oxford Instruments Analytical 2003 Analytical An • Cubic (Al, Fe) & ' "( ' # & ") # & * " + ' # & ' ", - # & ' ". # & "/ # Seven crystal systems
- 37. Oxford Instruments Analytical 2003 Analytical An 7 Crystal Symmetry Systems • Examples of all seven crystal systems solved Hexagonal Cubic Orthorhombic Trigonal Tetragonal Triclinic Monoclinic See the new dedicated EBSD website: http://www.EBSD.com 32/63
- 38. Oxford Instruments Analytical 2003 Analytical An Summary of Factors Affecting Pattern Quality • Band width varies with kV • Band contrast varies with kV • Band sharpness varies with kV • Camera Sensitivity (‘binning’ level/resolution) • Background removal • Integration time • Beam current (spot size) & current density • Vacuum level • Microscope resolution/aberrations Acquisition conditions affect the EBSP: • Atomic number • Grain size • Preparation damage/residues – surface contamination e.g. carbon from SEM • Surface oxidation or reaction products • Surface morphology • Surface coatings • Amorphised surface - ion milling Sample conditions affect the EBSP: The Hough Transform can be configured to optimize band detection for a wide range of operating and sample conditions... See the new dedicated EBSD website: http://www.EBSD.com 33/63
- 39. Oxford Instruments Analytical 2003 Analytical An Basic Modes of Operation 1. Point Analysis 2. Mapping See the new dedicated EBSD website: http://www.EBSD.com 34/63
- 40. Oxford Instruments Analytical 2003 Analytical An 0 1 0 1 ! ! 2 See the new dedicated EBSD website: http://www.EBSD.com Phase Discrimination 35/63
- 41. Oxford Instruments Analytical 2003 Analytical An Phase Discrimination by EBSD Kyanite Ilmenite Muscovite See the new dedicated EBSD website: http://www.EBSD.com 36/63
- 42. Oxford Instruments Analytical 2003 Analytical An Mapping General Examples See the new dedicated EBSD website: http://www.EBSD.com 37/63
- 43. Oxford Instruments Analytical 2003 Analytical An =100 µm; BC+E1-3; Step=1 µm; Grid298x216 3 1 3 Quartzite Visualisation of data - general microstructure See the new dedicated EBSD website: http://www.EBSD.com 38/63
- 44. Oxford Instruments Analytical 2003 Analytical An =100 µm; GB10; Step=1 µm; Grid389x286 Ni Superalloy Band Contrast + Grain Boundaries (high angle – general) See the new dedicated EBSD website: http://www.EBSD.com 39/63
- 45. Oxford Instruments Analytical 2003 Analytical An Band Contrast + Grain Boundaries + Twins/CSLs $ =100 µm; BC+GB10+SB; Step=1 µm; Grid389x286 See the new dedicated EBSD website: http://www.EBSD.com 40/63
- 46. Oxford Instruments Analytical 2003 Analytical An 0 3 1 Cu thin film See the new dedicated EBSD website: http://www.EBSD.com 41/63
- 47. Oxford Instruments Analytical 2003 Analytical An 3 4 Cu thin film See the new dedicated EBSD website: http://www.EBSD.com 42/63
- 48. Oxford Instruments Analytical 2003 Analytical An 4 See the new dedicated EBSD website: http://www.EBSD.com 43/63
- 49. Oxford Instruments Analytical 2003 Analytical An IPF-based orientation + pattern quality map Ta sputter target See the new dedicated EBSD website: http://www.EBSD.com 44/63
- 50. Oxford Instruments Analytical 2003 Analytical An 5 - 4 - See the new dedicated EBSD website: http://www.EBSD.com 45/63
- 51. Oxford Instruments Analytical 2003 Analytical An =100 µm; Map4; Step=0.75 µm; Grid600x450 0 Duplex Steel See the new dedicated EBSD website: http://www.EBSD.com 46/63
- 52. Oxford Instruments Analytical 2003 Analytical An Non-preheated Preheated Phase maps (+ GBs): red = ferrite, blue = austenite 0 5 See the new dedicated EBSD website: http://www.EBSD.com 47/63
- 53. Oxford Instruments Analytical 2003 Analytical An Unlike optical line-intercept GS analysis, twin boundaries and low-angle grain boundaries are positively identified and filtered from the data (if desired); tricky GB etch techniques not necessary; weaknesses of relying on reflected light orientation contrast are avoided Data available as text and in graphical format 4 - 0 ( ! 48/63 See the new dedicated EBSD website: http://www.EBSD.com
- 54. Oxford Instruments Analytical 2003 Analytical An =25 µm; Map4; Step=0.7 µm; Grid200x200 Aspect Ratios Major Axis Orientation =25 µm; Map5; Step=0.7 µm; Grid200x200 =25 µm; BC+GB+DT+E1-3; Step=0.7 µm; Grid200x200 4 0 49/63 See the new dedicated EBSD website: http://www.EBSD.com
- 55. Oxford Instruments Analytical 2003 Analytical An 0 6 - % 5 7' 8 9 76 1 ! ( 7 $ 7 5 + 7 0 7 "4 4 6 # See the new dedicated EBSD website: http://www.EBSD.com 50/63
- 56. Oxford Instruments Analytical 2003 Analytical An 0 1 2 3 4 5 6 0 100 200 300 400 500 Distance / microns Misorientation / degrees A B Misorientations relative to 1st data point Misorientations between adjacent data points A B * 0 % ! 4 See the new dedicated EBSD website: http://www.EBSD.com 51/63
- 57. Oxford Instruments Analytical 2003 Analytical An 0 % 5 $% See the new dedicated EBSD website: http://www.EBSD.com 52/63
- 58. Oxford Instruments Analytical 2003 Analytical An 0 • Isolate grains by strain See the new dedicated EBSD website: http://www.EBSD.com 53/63
- 59. Oxford Instruments Analytical 2003 Analytical An Strain (grain average misorientation) distribution map Strain (grain average misorientation) classification map Red = deformed Blue = Recrystallized Rolled Mo Sheet 54/63
- 60. Oxford Instruments Analytical 2003 Analytical An Rolling & heat treatment of Fe-Al binary alloy resulted in a partly deformed, partly recrystallized microstructure Grains subgrouped by residual strain state: Red deformed, blue recrystalllized 6 - See the new dedicated EBSD website: http://www.EBSD.com Texture ‘partitioning’ revealed 55/63
- 61. Oxford Instruments Analytical 2003 Analytical An =500 µm; BC; Ste p=1 µm; Grid1196x198 =500 µm; BC+MIS-5; Step=1 µm; Grid1196x198 Each orientation is surrounded by 8 nearest neighbors. The disorientation is calculated through all of the 8 nearest neighbors to get an averaged value. gij = gi gj -1 Disorientation angle (degrees) : See the new dedicated EBSD website: http://www.EBSD.com 56/63
- 62. Oxford Instruments Analytical 2003 Analytical An Cu Relative to selected reference point (cumulative rotation) For each pixel, relative to surrounding pixels (local rotation) : See the new dedicated EBSD website: http://www.EBSD.com 57/63
- 63. Oxford Instruments Analytical 2003 Analytical An Strain localization + GB map Ta sputter target : See the new dedicated EBSD website: http://www.EBSD.com 58/63
- 64. Oxford Instruments Analytical 2003 Analytical An Texture Analysis Pole Figures Inverse Pole Figures ODF 59/63
- 65. Oxford Instruments Analytical 2003 Analytical An ' 0 8 9 ; < < < = > =100 µm; BC+GB+DT+E1-3; Step=1 µm; Grid297x227 Quartzite 60/63
- 66. Oxford Instruments Analytical 2003 Analytical An ' 0 !? =25 µm; E1-3; Step=0.7 µm; Grid200x200 X0 0 0 1 1 1 1 1 0 1 Y0 Z0 Inverse Pole Figures (Folded) [Alumin.cpr] Aluminium (m3m) Complete data set 40000 data points Equal Area projection Upper hemispheres X0 001 111 101 Y0 Z0 Inverse Pole Figures (Folded) [Alumin.cpr] Aluminium (m3m) Complete data set 40000 data points Equal Area projection Upper hemispheres Half width:10° Cluster size:5° Exp. densities (mud): Min= 0.00, Max= 5.99 1 2 3 4 5 1 2 3 4 5 6 0 61/63
- 67. Oxford Instruments Analytical 2003 Analytical An φ2 =0 ° φ2 =0 ° φ2 =0 ° φ2 =0 ° φ2 =5 ° φ2 =5 ° φ2 =5 ° φ2 =5 ° φ2 =1 0 ° φ2 =1 0 ° φ2 =1 0 ° φ2 =1 0 ° φ2 =1 5 ° φ2 =1 5 ° φ2 =1 5 ° φ2 =1 5 ° φ2 =2 0 ° φ2 =2 0 ° φ2 =2 0 ° φ2 =2 0 ° φ2 =2 5 ° φ2 =2 5 ° φ2 =2 5 ° φ2 =2 5 ° φ2 =3 0 ° φ2 =3 0 ° φ2 =3 0 ° φ2 =3 0 ° φ2 =3 5 ° φ2 =3 5 ° φ2 =3 5 ° φ2 =3 5 ° φ2 =4 0 ° φ2 =4 0 ° φ2 =4 0 ° φ2 =4 0 ° φ2 =4 5 ° φ2 =4 5 ° φ2 =4 5 ° φ2 =4 5 ° φ2 =5 0 ° φ2 =5 0 ° φ2 =5 0 ° φ2 =5 0 ° φ2 =5 5 ° φ2 =5 5 ° φ2 =5 5 ° φ2 =5 5 ° φ2 =6 0 ° φ2 =6 0 ° φ2 =6 0 ° φ2 =6 0 ° φ2 =6 5 ° φ2 =6 5 ° φ2 =6 5 ° φ2 =6 5 ° φ2 =7 0 ° φ2 =7 0 ° φ2 =7 0 ° φ2 =7 0 ° φ2 =7 5 ° φ2 =7 5 ° φ2 =7 5 ° φ2 =7 5 ° φ2 =8 0 ° φ2 =8 0 ° φ2 =8 0 ° φ2 =8 0 ° φ2 =8 5 ° φ2 =8 5 ° φ2 =8 5 ° φ2 =8 5 ° Φ =9 0 ° Φ =9 0 ° Φ =9 0 ° Φ =9 0 ° φ1 =9 0 ° φ1 =9 0 ° φ1 =9 0 ° φ1 =9 0 ° 1 1.5 2 2.5 =100 µm; BC+GB+DT+E1-3; Step=1 µm; Grid297x227 ' 0 " # 62/63
- 68. Oxford Instruments Analytical 2003 Analytical An Thank you See the new dedicated EBSD website: http://www.EBSD.com 63/63