CrossCourt 3 Technical Product Description

 

BLG Productions has teamed up with Vantage Software Inc. to bring you CrossCourt 3 for EBSD strain analysis and measurement.

Residual Strain affects most aspects of material performance.  Crosscourt EBSD analysis software opens up a window in material science allowing the precise measurement of residual elastic & plastic strain at the submicron level and at a sensitivity of better than 2 parts in 10000.

 

 

Precision EBSD and Strain Measurement

A thorough knowledge of the strain distribution at all scales is important for a wide range of measurements, including:

  • Crack nucleation and propagation in structural materials. E.g. Stress Corrosion Cracking and the effect of thermal and mechanical strains near inclusions.
  • The efficiencies of Fuel cells and Solar cells as well as Optoelectronic, Ferroelectric and Piezoelectric devices.
  • Thin Film Growth e.g. thermal strains, misfit dislocation numbers.

 

 

History

CrossCourt was developed in 2005 as a tool for the semiconductor industry to allow the measurement of elastic strain in semiconductors. Following its thorough testing in this field, it has been expanded to provide additionally measurements of plastic deformation at a precision of around 80x better than existing EBSD based methods.

 

Customer Applications

Current customers are now using CrossCourt in the aerospace, the nuclear and solar power industries as well as the semiconductor industry. Many groups are using it as a research tool – enabling them to see directly for the first time, effects that have been largely theoretical or hitherto unexplored.

Our customers’ investigations have already shed light on:

  • How microstructural features can cause stress concentrations that lead to crack initiation and propagation.
  • How triple junctions can cause elastic strain levels higher than the plastic strain yield point.
  • The mechanisms of twin formation and propagation.
  • Quantitative lower bound estimates of geometrically necessary dislocation densities.

 

 

 

 

With CrossCourt 3 what were historically theoretical calculations are now measurable.

 

CrossCourt 3 is 80 times more sensitive than traditional EBSD analysis

 

Without the advanced features of CrossCourt3 the details revealed in the Kernel Average Misorientation Map (below) are not visible through traditional EBSD analysis (top).

 

 

 

 

 

 

 

How It Works

CrossCourt measures shifts across stored patterns relative to a reference pattern. The shifts are used to calculate the full distortion matrix. This method is very sensitive and offers high precision (0.006º sensitivity) compared to the Hough transform (0.5º).

As an extension of traditional EBSD application software, CrossCourt uses results from existing systems and cross correlation techniques to measure very small changes between each pattern and a reference pattern.

Measurements include:

Elastic strain tensor – including normal strain and shear strains.

Accurate misorientation– around 80 times more sensitive than the Hough transform used by traditional EBSD systems.

Geometrically necessary dislocation numbers.

Entire stress/strain tensor – for comparison with the output of theoretical calculations of strain distribution using established Finite Element modelling methods.

 

 

Requirements

CrossCourt 3 is a standalone software application for Microsoft Windows XP and Windows 7 and will run alongside any EBSD application that is capable of collecting patterns and measurements at 1000 x 1000 pixel resolution.

 

 

 

 

 

Precise Crystallographic Misorientations


 

 

 

 

 

 

 

 

All measurement is radians. Data courtesy of Oxford University

Lattice rotations (left) resulting from plastic zone and wake around fatigue crack growth in Ni -based superalloy at elevated temperature.  Evidence of compressive residual stresses across crack plane  (right) for innermost part of plastic zone.