![]() |
|
Use this resource: |
![]() |
Link to this page: | http://core.materials.ac.uk/search/detail.php?id=1648 |
---|
View at: | ![]() ![]() ![]() |
---|---|
Resource type: | Image |
Description: | Solidification initiates on the mould walls because this is where the melt is coolest and because inhomogeneities promote nucleation. Selective growth then occurs, whereby the grains which have their easy growth direction <100> parallel to the heat flow direction grow fastest, and cut off the paths of less well-aligned grains. This results in a 'columnar zone' which may extend to the centre of the casting but often gives way to an 'equiaxed zone'. The equiaxed grains may result from sedimentation from the free surface, from the detachment of dendrite tips, or simply from heterogeneous nucleation ahead of the advancing front (though the latter is only likely if deliberate 'melt inoculation' has been implemented). |
Keywords: | alloy • aluminium • cast • casting • chill zone • columnar • equiaxed • metal |
Categories: | Science approaches > Microstructure Materials > Metals & alloys > Aluminium & alloys Processes > Shaping > Casting Testing, analysis & experimentation > Metallography Scale > Micro |
Created by: |
Prof T W Clyne, Department of Materials Science and Metallurgy, University of Cambridge DoITPoMS, University of Cambridge |
Published by: | DoITPoMS, University of Cambridge | License: | This resource is released under the Creative Commons Attribution Non-Commercial Share Alike license (2.0 UK: England & Wales). View the full legal code here. |
Date created: | 03 October 2002 |
Date added: | 21 August 2009 |
Package: | |
Resource ID: | 1648 |