The Diffusion of Copper in Iron
01 Oct 1968-Journal of Applied Physics (American Institute of PhysicsAIP)-Vol. 39, Iss: 11, pp 5041-5044
TL;DR: In this article, a large discontinuity in the Arrhenius plot of the lattice diffusion coefficient at the α-γ transformation was observed, contrary to the data of Anand and Agarwala [J. Appl. Phys. 37, 4248].
Abstract: Measurements of the diffusion of 64Cu in pure and impure α and γ iron show a large discontinuity in the Arrhenius plot of the lattice diffusion coefficient at the α‐γ transformation, contrary to the data of Anand and Agarwala [J. Appl. Phys. 37, 4248 (1965)]. Grain‐boundary diffusion predominates at T≤815°C in the α phase and at T≤1250°C in the γ phase. Trapping of the radioactive copper by inclusions or impurities in solution also appears to have a profound effect on the diffusion process.
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01 Jun 1970
TL;DR: The diffusion rates of chromium, vanadium, and hafnium in α- and γ-Fe have been determined by radiotracer techniques as discussed by the authors, and the results are (in sq cm sec−1): α-Fe γ -Fe ChromiumD = 8.52 exp (−59,900/RT)D = 10.80 exp(−69,700/RT).
Abstract: The diffusion rates of chromium, vanadium, and hafnium in α- and γ-Fe have been determined by radiotracer techniques. The results are (in sq cm sec−1): α-Fe γ-Fe ChromiumD = 8.52 exp (−59,900/RT)D = 10.80 exp(−69,700/RT) VanadiumD = 3.92 exp (−57,600/RT)D = 0.25 exp (−63,100/RT) HafniumD = 1.31 exp (−69,300/RT)D = 3600 exp (−97,300/RT) The differences in diffusion rates are discussed in terms of the compressibility of the diffusing atom. Diffusion of chromium in γ-Fe was also measured by a microprobe analysis technique. The result is:D = 4.08 exp (−68,500/RT) Comparison is made between diffusion analysis by tracer techniques and by electron probe microanalysis.
244 citations
TL;DR: In this article, the chemical diffusion coefficients and the solubility limits of copper in iron were determined in the temperature range 690-1050 C by electron probe microanalysis.
Abstract: The chemical diffusion coefficients and the solubility limits of copper in iron were determined in the temperature range 690–1050 °C by electron probe microanalysis. Specimens were large‐grained polycrystals for the γ‐iron and single crystals for the α‐iron. The iron contained less than 11 wppm of impurities and had a resistivity ratio R293 °K/R4.2 °K up to 8700. The results for the diffusion coefficients are (in cm2/s) DγCu=0.19 exp(−65 100/RT) and DαCu=300 exp(−67 800/RT). An anomalous decrease of the diffusion below the Curie point was observed.
204 citations
TL;DR: In this article, a physics-based modelling framework to describe microstructure and mechanical properties in maraging steels is presented, which is based on prescribing the hierarchical structure of the martensitic matrix, including dislocation density, and lath and high-angle grain boundary spacing.
113 citations
94 citations
TL;DR: In this paper, the authors measured self-diffusion in silver single crystals at temperatures between 270 and 500 °C and found that the Arrhenius plot is curved owing to a large divacancy contribution.
Abstract: Self-diffusion in silver single crystals was measured at temperatures between 270 and 500 °C. The diffusion coefficients were in the range of 3×10−18 to 2×10−13 cm2/s. The results indicate that the Arrhenius plot is curved owing to a large divacancy contribution and that the activation energy for diffusion by divacancies is temperature dependent due to a partial dissociation of the divacancies. The best values of the parameters for diffusion by monovacancies are Do= 0.041 cm2/s, Q = 1.76 eV.
83 citations
References
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Book•
01 Jan 1956
TL;DR: Though it incorporates much new material, this new edition preserves the general character of the book in providing a collection of solutions of the equations of diffusion and describing how these solutions may be obtained.
Abstract: Though it incorporates much new material, this new edition preserves the general character of the book in providing a collection of solutions of the equations of diffusion and describing how these solutions may be obtained
20,495 citations
TL;DR: In this article, the exact solution of the grain boundary diffusion problem is evaluated numerically and the results presented in graphical form suitable for immediate application to the commoner types of experimental measurement of D?, the grain surface diffusion coefficient.
Abstract: Whipple's exact solution of the grain boundary diffusion problem is evaluated numerically and the results presented in graphical form suitable for immediate application to the commoner types of experimental measurement of D?, the grain boundary diffusion coefficient. This enables a detailed comparison to be made between the results obtained using the exact solution and the approximate but commonly employed Fisher solution. The most interesting result is that indiscriminate use of the Fisher equation may lead to anomalously high activation energies for grain boundary diffusion, especially in low angle boundaries. The Whipple solution is also compared with another exact solution due to Suzuoka, which employs a different surface condition from the one assumed by Whipple. For the sectioning method of measurements the two solutions will give nearly the same value of D?. This is a distinct advantage for this method over others, for the conditions prevailing at the surface in a grain boundary experiment are not easily controllable. Mathematical treatments of grain boundary diffusion by other authors are briefly mentioned. Most of these give results already contained in the Whipple solution.
581 citations