DAS Dentrite Arm Spacing

Determination of quantitative microstructural properties

The dendrite arm spacing (DAS) is a parameter for the determination of quantitative microstructural properties, in particular it is used to calculate the local solidification times in a cast structure. For one sample, a measurement series can be created from several images.

Parameters

  • Length of the measurement range (also accumlated for all distances in the picture and measurement series)
  • Number of measured dendrite arms (also accumulated in the whole measurement series)
  • Median DAS of the current dendrite
  • Average DAS
  • Variance and median of the average DAS
  • Local solidification time

Calculation

In order to determine the middle dendrite arm spacing λa, the length of the dendrite arms and the total spacing between those arms are measured with the microstructures. The local solidification time is calculated with the middle dendrite arm spacing λa.

Functionality

  • Measurement according to BDG guideline P220: "Determination of dendritic arm spacing for castings made of cast aluminum alloys"
  • Determination of measuring lines for at least 5 parallel dendrite arms
  • Automated line detection with the option to manually correct the position and number of arms
  • Generation of measuring series data for image series
  • Interface to image data bases, transfer of images, diagrams and measurment tables
  • Logging (MS Word and MS Excel)
  • Determination of a 2D diagram showing the solidification process