Professor DJ Dingley

“I would like to welcome you to this website which I hope you might find useful in your application and in possible further development of the EBSD technique.”
“Despite some rumors floating around I have not retired to the South of France although yes I do visit there quite a bit but the internet is a wonderful thing and no one is out of reach nowadays.
Talking with colleagues around the world they thought it might be a good idea to disscus problems experienced in utilizing the EBSD technique, difficulties with certain crystal systems and queries about the newly emerging techniques could be aired and answers provided. They suggested that I was in a good position to host such a sevice with my long experience in EBSD as an academic at Bristol University where I currently hold a visiting professorship, and as a system provider, via Oxford Instruments in the very early days and TSL from its foundation. I am currently independent of both of these concerns but I am pleased to admit I do have an interest as a consultant in BLG productions. This is a start up company established by ex Bristol students to provide application software in areas not covered by the major EBSD providers.
So let’s see how it goes.” – Thank you – professor DJ Dingley

 

Professor DJ Dingley has pioneered the development and understanding of automated EBSD (Electron BackScatter Diffraction) science and technology.  He established a key research program at Bristol University in the early ’70′s after completing a Post-Docterate in Physics at Stanford University, California.  In the late 80′s research into EBSD began to migrate to industry where David helped introduced the first commercially available system.  In the early 90′s he established TSL (TexSEM Laboratories Inc.) together with John Bennion and Dr Brent Adam’s in the USA on the back of those early installations.  He now resides in Cornwall, England enjoying the ocean breezes and surfing!

If you would like to join in on conversations about EBSD then please send us a message from the ‘Contact Us’  and we will reply shortly.

EBSD Strain Software

HR (high angular resolution) EBSD and strain measurement software – Crosscourt 3
Scientists and associates are continually pushing for improved analytical capabilities to better understand their materials. BLG Vantage has responded by creating a unique, powerful and easy to use product that enables the measurement of strain at the microscopic level – providing data never before possible!

Vist BLGVantage for our latest development in Strain Mesurement

Feature Summary

  • Map residual strain at the full spatial resolution of your EBSD system
  • Determine the full strain and rotation tensors to 1 part in 10,000 precision
  • Measure lattice misorientation to better than 1/100 degree
  • Calculate all 9 stress components and the Mises Stress
  • Analyse metals, semiconductors & mineralogical samples from all crystal systems
  • Produce High Resolution Kernel Average Misorientation Maps (HR KAM)
  • Map GND distributions (Geometrically Necessary Dislocations)
  • Import data from Bruker CrystAlign, EDAX OIM,  Oxford Instruments Inca and AZtec EBSD data collections systems
  • Export all results to Excel or Matlab for further analysis
  • Uses cross correlation techniques to measure EBSD pattern shifts to 1/20 pixel resolution
  • Access 2 separate measurements of the data quality
  • Easily adjust measurement parameters before and after cross-correlation

Find out more about this  system now


Crosscourt 3

Residual strain is a microstructural parameter which is of considerable importance but historically difficult to measure. Fortunately, recent advances in Electron Backscatter Diffraction have now made possible strain quantification at both high precision and accuracy. Cross correlation between EBSD patterns obtained from strained and unstrained regions of a crystal can be used to measure normal and shear strains at the 1 part in 10000 level.

CrossCourt 3 is a software package that determines the full strain tensor and local strain gradient in single and polycrystalline specimens by measuring the distortion of EBSD patterns recorded in sequence across the sample. The EBSD patterns are collected using either the EDAX_TSL OIM DC or Oxford_HKL data collection systems.

 

The cross correlation method has been tested and proven accurate through a large number of studies. The example shown here is of the stress distribution adjacent to a crack induced in germanium.

The release of CrossCourt 3 marks the culmination of five years of the development and testing of this technique.

 

Stress distribution adjacent to a lenticular crack in germanium.

Elastic shear strain distribution surrounding carbide precipitate in Ni Base alloy. (x10-4)

 Recent published studies have included mapping grain boundary strain in polycrystalline Ni base alloys, strains adjacent to fatigue cracks, and strains surrounding carbide precipitates in the annealed and post deformation stages. In the semiconductor field strain measurements have been determined in both plan view and cross section for SiGe/Si gate structures and ELOG GaN blue lasers.

Extension to NBD

To extend the spatial resolution limit below the 60nm level possible with EBSD, the CrossCourt3 software has been adopted for use with Nano Beam Diffraction Patterns. It functions in a similar way to the proven EBSD method by comparing an NBD pattern from a strained area with that from a reference unstrained area.The effect on strain measurement of differences in diffraction pattern centre and spot shape are minimized using an auto correlation function applied to patterns from both the strained and the unstrained reference areas. The method takes advantage of the high current, well collimated beam and extremely small probe size achievable in a modern dedicated STEM system.

Analysis of this pattern taken in a Hitachi 2300 STEM, allowed us to determine the normal strains parallel to [220] and [002] directions, the shear strain in the (1-10) plane and rotation about [1-10].

 

 

 

 

 

 

 

 

The Data opposite was collected using a 2kx2k video camera fitted to an Hitachi S2300 microscope.Beam control and diffraction pattern collection were made using EDAX_TSL OIMDC software.CrossCourt3 calculates all strain values automatically and provides output as two dimension micrographs or one dimensional line traces.

 

If you would like more information about Crosscourt 3 and developments now click here

 

 


Crosscourt 3

More about Strain Mesurement visit BLGVantage