The diffusion and solubility of iron in copper

Abstract

The chemical diffusion coefficients and the solubility limits of iron in copper were determined in the temperature range 650–1050 °C by electron probe microanalysis. Specimens were 99.999% copper single crystals. The diffusion is best described by two regression lines: DFe-Cu=0.504 exp(−49740/RT) cm2/s for the temperature interval 1050–800 °C and DFe-Cu=0.091 exp(−46140/RT) cm2/s for the temperature interval 800–650 °C. The solubility of iron in copper is given to logC=2.951−3357(1/T °K) wt% in the temperature range 1050–650 °C.

Formation of Transition Phases on Interface between Monocrystalline Fe and Cu Due to Mutual Solid-State Diffusion

“…In the previous experiments the evaporated layer of a metal was rather thin: 4 μm of copper [6], 0.1 μm of copper [9] or 1.5-3 μm of iron [7]. Here, it is observed that thickness of interaction layer is even 50 μm (Fig.…”

“…1,2] and later [3][4][5][6][7][8]. It was observed, that diffusivities of elements is different in paramagnetic and ferromagnetic state; for example diffusivity of copper in polycrystalline iron is D Cu/Fe = 0.57exp(-57000/RT) (cm 2 /s) in temperature range 800-1050ºC and D Cu/Fe = 0.47exp(-58380/RT) (cm 2 /s) in temperature range 650-750ºC [9].…”

“…A bit different results are given by Salje et al in [6]: D Cu/ γFe = 0.19exp(-65100/RT) and D Cu/αFe = 300exp(-67800/RT) (cm 2 /s). The values of diffusivity of iron in copper are also reported in other papers [7,8]. For the sake of clarity, data on diffusion coefficient in Fe-Cu system are collected in Table 1.…”

“…For the sake of clarity, data on diffusion coefficient in Fe-Cu system are collected in Table 1. Even though the papers [6][7][8] discuss the diffusion coefficients that vary strongly, it may be caused by the fact that authors deal with annealing of thin evaporated layer on monocrystalline metallic substrate [6,7], thus the differences in D Cu/Fe and D Fe/Cu may be caused by anisotropy. It is also worth noting that precise orientation of the substrate single crystals is not mentioned.…”

“…It is also worth noting that precise orientation of the substrate single crystals is not mentioned. Anyway, the obtained concentration-penetration curves are monotonic [6][7][8][9], only Anand et al [9] show change of temperature dependence of diffusivity of copper in iron.…”