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Journal ArticleDOI

Thermodynamics and phase diagram of the Fe-C system

TL;DR: A critical review of published data provides a fairly accurate knowledge of the thermodynamic properties of all of the phases of the system Fe-C that are stable or metastable at atmospheric pressure as discussed by the authors.
Abstract: A critical review of published data provides a fairly accurate knowledge of the thermodynamic properties of all of the phases of the system Fe-C that are stable or metastable at atmospheric pressure. Selected data are shown as tables and equations. A proposed phase diagram differs only slightly from others recently published but has the following features. Peritectic compositions and the α-γ equilibrium are shown to agree with measured values of the activity of iron in the solid and liquid solutions and the thermodynamic properties of pure iron. Of all the reported carbides of iron only two may be studied under equilibrium conditions. The solubilities of cementite and of χ-carbide in α-Fe are deduced from measured equilibria. Both are metastable at all temperatures with respect to graphite and its saturated solution in iron. The χ-carbide becomes more stable than cementite below about 230° Certain published data on e-carbide permit an estimate of its free energy as a precipitate during the aging process.
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Book
01 Jan 1981

697 citations

Journal ArticleDOI
A.R. Miedema1
TL;DR: In this article, it has been shown that a relatively simple atomic model does account for the sign of the heat of formation, ΔH, in a wide variety of alloy systems.
Abstract: In Part I of this paper [1] it has been shown that a relatively simple atomic model does account for the sign of the heat of formation, ΔH, in a wide variety of alloy systems. Here we consider numerical values of ΔH for solid alloys; a quite satisfactory agreement is obtained for the heat of formation of intermetallic compounds of transition metals, including their borides, carbides and nitrides. Transition metal suicides, germanides, carbides, and nitrides, can be treated in the same way as the other compounds if one allows for an additional positive energy contribution required to convert elementary Si, Ge, C or N2 into a metal (8, 6, 24 and 57 kcal per gram-atom of these four elements, respectively). As an example, predictions for heats of formation of binary intermetallic compounds containing a rare-earth element have been tabulated.

472 citations

Journal ArticleDOI
TL;DR: In this paper, the crystal chemistry and the occurrence of carbides and nitrides in steels are reviewed and the characteristics of nitrogen are emphasised and are related to the behaviour of carbon.

313 citations

Journal ArticleDOI
Nan Liu1, Lei Fu1, Boya Dai1, Kai Yan1, Xun Liu1, Ruiqi Zhao1, Yanfeng Zhang1, Zhongfan Liu1 
TL;DR: This work reports a universal segregation growth technique for batch production of high-quality wafer-scale graphene from non-noble metal films and demonstrates the first example of monolayer and bilayer graphene wafers using Cu-Ni alloy by combining the distinct segregation behaviors of Cu and Ni.
Abstract: Graphene has been attracting wide interests owing to its excellent electronic, thermal, and mechanical performances. Despite the availability of several production techniques, it is still a great challenge to achieve wafer-size graphene with acceptable uniformity and low cost, which would determine the future of graphene electronics. Here we report a universal segregation growth technique for batch production of high-quality wafer-scale graphene from non-noble metal films. Without any extraneous carbon sources, 4 in. graphene wafers have been obtained from Ni, Co, Cu−Ni alloy, and so forth via thermal annealing with over 82% being 1−3 layers and excellent reproducibility. We demonstrate the first example of monolayer and bilayer graphene wafers using Cu−Ni alloy by combining the distinct segregation behaviors of Cu and Ni. Together with the easy detachment from growth substrates, we believe this facile segregation technique will offer a great driving force for graphene research.

245 citations

Journal ArticleDOI
TL;DR: In this article, the authors determined high-pressure melting curves for Fe3C, Fe7C3 and the Fe-Fe3C eutectic using laser-heated diamond anvil cell techniques.

222 citations


Cites background from "Thermodynamics and phase diagram of..."

  • ...60 The iron-rich portion of the Fe-C binary system has been studied extensively at 1 atm and 61 modest pressures due to its importance in metallurgy (e.g. Chipman, 1972; Strong and Chrenko, 62 1971), as shown in Fig....

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  • ...square indicates the 1 atm eutectic from Chipman (1972)....

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  • ...The iron-rich portion of the Fe–C phase diagram at 1 atm after Chipman (1972)...

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  • ...The iron rich portion of the Fe-C phase diagram at 1 atmosphere after Chipman (1972) and 711 at 5.7 GPa after Strong and Chrenko (1971)....

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  • ...The filled square 791 indicates the 1 atmosphere eutectic from Chipman (1972)....

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