Table of Contents
ISRN Metallurgy
Volume 2012 (2012), Article ID 750914, 9 pages
http://dx.doi.org/10.5402/2012/750914
Research Article

Thermal Expansion Behaviour of Ternary Nickel-Based, Cobalt-Based, and Iron-Based Alloys Containing Very High Fractions of Carbides

Team 206 “Surface and Interface, Chemical Reactivity of Materials”, Department of Chemistry and Physics of Solids and Surface, Institut Jean Lamour (UMR CNRS 7198), Faculty of Sciences and Technologies, University of Lorraine, Boulevard des Aiguillettes, BP 70239, 54506 Vandoeuvre-lès-Nancy, France

Received 27 August 2012; Accepted 13 September 2012

Academic Editors: F. Hori and M.-C. Wang

Copyright © 2012 Patrice Berthod and Lionel Aranda. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Some of the wear-resistant pieces or coatings, constituted of a metallic matrix and of carbides present in high fractions, are a mix, in similar quantities, of two materials displaying greatly different levels of hardness but also of thermal expansion coefficient. When temperature increases, the second difference of property may lead to particular geometrical behaviours. To study these differences, nine nickel-based, cobalt-based, and iron-based alloys containing very high quantities of carbides were elaborated by foundry. In their as-cast conditions, the microstructures of these alloys were characterized; their hardness and thermal expansion until 1200°C were measured and analysed, with regard to the evolution of the structures predicted by thermodynamic calculations. The hardness of the alloys is high (nickel alloys) or very high (cobalt and iron alloys, 600 Hv and more) while the thermal expansion is greatly influenced by carbides, notably when temperature has become very high. Some of the variations of thickness at the end of heating or during an isothermal stage at 1200°C, essentially contraction, directly result from the mechanical interaction between matrix and carbides which was accumulated during the heating.