Choose a magnification that clearly distinguishes the phase of interest from all others. The rule of thumb: the spacing between grid points should be such that no feature is counted more than once, but small enough to sample the structure adequately. The standard suggests that the grid spacing should be roughly the size of the features of interest.
Quantifying graphite nodularity or flake graphite area fraction. astm e562-19e1
Most people assume that if you want to know how much of a material is porosity, ferrite, or graphite, you’d use a computer. But ASTM E562-19e1 defends a deceptively simple, manual method: the manual point count. It’s a testament to how systematic random sampling and basic statistics can outperform intuition—and even some automated systems—in metallography and materials science. Choose a magnification that clearly distinguishes the phase
Before diving into the methodology, it is essential to decode the title: Place the grid on the microstructure at a
This standard supersedes previous versions (E562-11, E562-08, etc.) and is recognized globally across industries that require microstructural analysis.
Place the grid on the microstructure at a random starting position (e.g., random x-y shift). Then move the stage in a systematic pattern (e.g., a serpentine or raster scan) across the sample to avoid bias. Avoid revisiting the same area.