What is grain size: Definition and 11 Discussions

Grain size (or particle size) is the diameter of individual grains of sediment, or the lithified particles in clastic rocks. The term may also be applied to other granular materials. This is different from the crystallite size, which refers to the size of a single crystal inside a particle or grain. A single grain can be composed of several crystals. Granular material can range from very small colloidal particles, through clay, silt, sand, gravel, and cobbles, to boulders.

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  1. R

    XRD for grain size measurement

    Hello, Could you explain or prompt me to an article or source that mentions the advantages/setbacks from measuring the grain size of materials using X-Ray Diffraction (XRD)?
  2. A

    How Does Dust Grain Size Compare to Wavelength in Scattering Light?

    Hey everyone, So I've been killing myself trying to find a good reference that talks about the wavelength dependence of dust grains when the size of the grain is about the size of the incoming light, or s~lambda. I have numerous references for when s<<lambda (absorption dominates with a...
  3. K

    Grain size and grain boundary diffusion

    Hi all, I was wondering if anyone knows of any literature that explains why larger grains "absorb" smaller grains during cross-boundary diffusion in solid state diffusion. I read a book that explains it analogously in terms of pressure differences and boundary tension but I'm not quite happy...
  4. Z

    Grain size estimation in glacing angle XRD

    Hello everyone, I met a problem in XRD. Using theta-2theta mode I can not find crystalline peaks in my thin film sample because most within it is amorphous phase. However, I get three clear peaks using the glacing mode,i.e. theta-theta mode. Now i want to calculate the grain size in terms...
  5. K

    Relationship interatomic spacing or interplanar spacing and grain size

    is interplanar spacing or interatomic spacing directly proportional to grain size?
  6. Y

    Grain Size and Formula Clarification

    1) Hi just checking if the definition of grain size is the average size of grains in a metal expressed as average diameter. if it is not or if there is a more accurate definition could u define it for me. 2) and if the formula N=2n-1 or is it N=2^(n-1) n being the number of grains per square...
  7. S

    Ferromagnetic effect at smaller/larger grain size

    Hi everybody, I have faced with a problem in my report. The question said that "How can ferromagnetic effect change to depend on particle/grain size(at nm (10, 50, 100, 1000...) and at \mum (0.5, 1, 2...)?" (In shortly, what can we observe at feromagnetic effect if we increase and decrease of...
  8. S

    Decreasing grain size with element addition

    Hello, I have found that in some processing cases that additional elements are added to metals which result in increased potential for smaller grain size. Does anyone know why this is so? Am I signiificantly misunderstanding the issue? Thanks, -scott
  9. A

    Grain Size of Ceramics: Why Larger is Smaller for Diffusivity

    Why is it that the larger the grain size, the smaller the grain-boundary contribution to diffusivity?
  10. T

    Grain Size Hardening: Dislocation Sources and their Effects on Yield Strength

    Hi all I am learning about Grain Size Hardening, and find it difficult to understand some concepts. With refer to the link: http://aluminium.matter.org.uk/content/html/eng/default.asp?catid=64&pageid=1000301064 What is that dislocation source, and why it emits dislocation when the stress is...