Image icon  Cu 70, Ni 30 (wt%), cored dendrites

Use this resource: Use this resource icon
Link to this page:
View at:            
Resource type: Image
Description: This alloy is typical of many copper based alloy systems. The dendrite structure shows coring (variation in solute concentration). The light areas are rich in nickel and the darker areas are low in nickel. Chill casting extracts heat quickly enough to prevent significant solid state diffusion, resulting in cored dendrites. The centres of the dendrites that cool near the liquidus temperature, are nickel rich compared to the outer layers that solidify at progressively lower temperatures. Because the partition coefficient is positive the outer layers solidify with progressively lower nickel concentrations. The observed pattern results from the intersection of the plane of polish and the randomly orientated regions of equal solute concentration.
Keywords: alloy • copper • coring • dendrite • metal • nickel • partition coefficient
Categories: Science approaches > Microstructure
Materials > Metals & alloys > Copper & alloys
Materials > Metals & alloys > Nickel & alloys
Testing, analysis & experimentation > Metallography
Scale > Micro
Created by: DoITPoMS, University of Cambridge
Prof T W Clyne, Department of Materials Science and Metallurgy, 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).
Creative Commons Attribution Non-Commercial Share Alike logo
You are free:
  • to share – to copy, distribute and transmit the work
  • to remix – to adapt the work
Under the following conditions:
  • attribution – You must attribute the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the work).
  • noncommercial – You may not use this work for commercial purposes.
  • share alike – If you alter, transform, or build upon this work, you may distribute the resulting work only under the same or similar license to this one.
View the full legal code here.
Date created: 25 October 2001
Date added: 21 August 2009
Resource ID: 1074