Self-Diffusion, Solute-Diffusion and Interdiffusion in Binary Intermetallics

2014 ◽  
Vol 2 ◽  
pp. 1-72 ◽  
Author(s):  
Helmut Mehrer
Keyword(s):  
Boundary Diffusion ◽  
Functional Materials ◽  
Tracer Diffusion ◽  
Solute Diffusion ◽  
Diffusion Couples ◽  
Self Diffusion ◽  
Solid Diffusion ◽  
State Diffusion ◽  
Iron Nickel ◽  
Kinetics Of

800x600 Intermetallics are compounds of two metals or of metal(s) and semimetal(s). Their structures are usually different from those of the constituents. Some intermetallics are interesting functional materials, others have attracted attention as high-temperature structural materials. We remind the reader of some fundamentals of solid-state diffusion and to the major techniques for tracer diffusion measurements, interdiffusion studies and the growth kinetics of layers in solid diffusion couples. Starting from self-diffusion, which is the most basic diffusion phenomenon in any solid, the paper covers the main features of diffusion in binary intermetallics from the systems Cu-Zn, Ni-Al, Fe-Al, Mg-Al, Ni-Ge, Ni-Ga, Fe-Si, Ti-Al, Ni-Mn, Mo-Si, Co-Nb and Ni-Nb.. We illustrate the influence of phase transitions on diffusion and point out some common features of diffusion in intermetallics. We discuss in detail diffusion in silicides of iron, molybdenum and of silicides of refractory metals. We also consider aluminides of iron, nickel, and titanium and in the aluminium-magnesium system. We consider diffusion in intermetallics of the cobalt-niobium and nickel-niobium system and in in the Nb-Sn and V-Ga systems. We finish with some remarks about grain boundary diffusion in intermetallics. Normal 0 21 false false false UK X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif";}

Growth kinetics of phases in solid-state diffusion couples

1995 ◽  
Vol 152 (2) ◽  
pp. 385-392 ◽  
Author(s):  
V. H. Garcia ◽  
C. Scherer ◽  
P. M. Mors
Keyword(s):  
Solid State ◽  
Growth Kinetics ◽  
Solid State Diffusion ◽  
Diffusion Couples ◽  
State Diffusion ◽  
Kinetics Of

Diffusion in Metallic Elements and Intermetallics

2009 ◽  
Vol 289-292 ◽  
pp. 15-38 ◽  
Author(s):  
Helmut Mehrer ◽  
Sergiy V. Divinski
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Ternary System ◽  
Functional Materials ◽  
Lattice Diffusion ◽  
Solid State Diffusion ◽  
Metallic Elements ◽  
Self Diffusion ◽  
Bcc Metals ◽  
State Diffusion

Starting from some fundamentals of solid-state diffusion, we remind the reader to the major techniques for lattice diffusion measurements. Self-diffusion is the most basic diffusion phenomenon in any solid. The paper covers main features of self-diffusion in pure fcc and bcc metals and some important facts about diffusion of substitutional solutes in metals. Binary intermetallics are compounds of two metals or of a metal and a semimetal. Their structures are different from those of the constituents. Some intermetallics are interesting functional materials others have attracted attention as high-temperature structural materials. The paper reviews some results mainly from our laboratory on diffusion in binary intermetallics from the systems Cu-Zn, Ni-Al, Fe-Al, Ni-Ge, Ni-Ga, Fe-Si, Ti-Al, Ni-Mn, Mo-Si and Co-Nb, which have been published in detail elsewhere. Some results for the ternary system Ni-Fe-Al are also mentioned.

Grain Boundary Induced Lateral Propagation of Intermetallic Phases in Nano-Grained Cu-Sn Thin Film Couples

2009 ◽  
Vol 7 ◽  
pp. 59-68 ◽  
Author(s):  
Yuri S. Kaganovsky ◽  
Lyudmila N. Paritskaya ◽  
V.V. Bogdanov
Keyword(s):  
Thin Film ◽  
Grain Size ◽  
Grain Boundary ◽  
Tracer Diffusion ◽  
Coarse Grained ◽  
Reactive Diffusion ◽  
Diffusion Couples ◽  
Cu3sn Phase ◽  
Phase Propagation ◽  
Kinetics Of

The kinetics of lateral Cu6Sn5 and Cu3Sn phase propagation induced by grain boundary (GB) interdiffuson in thin-film diffusion couples Cu-Sn were studied in a temperature range 160-180oC by optical microscopy, AFM, SEM, and energy-dispersive X-ray spectroscopy (EDS). Nano-grained Cu and Sn films were sequentially deposited on glass substrates with 5 – 20 µm overlap. To prevent surface diffusion and thus separate GB-diffusion contribution into kinetics of phase propagation, the surfaces of diffusion couples were covered by a thin (20 – 40 nm) carbon layer. It was found that the rates of lateral Cu6Sn5 and Cu3Sn phase spreading in thin-film couples exceed several times the spreading rates of the same phases over the surface of coarse-grained samples and 50 – 70 times exceed the rates in the bulk of massive samples. Kinetics of lateral phase spreading both in thin-film and in massive diffusion couples obeys parabolic law. Similarly to A and B regimes for GB tracer diffusion, A and B regimes of GB reactive diffusion were found in the spreading Cu3Sn phase. The kinetics of the phase propagation turned out independent of the film thickness (in the range 40 – 200 nm) if the films possessed similar grain size, whereas the kinetics was rather sensitive to the grain size and GB structure. Theoretical analysis of the phase propagation kinetics accelerated by GB diffusion has been done and the phase propagation rates have been calculated. By comparison experimentally measured phase propagation rates with the calculated ones we determined the GB diffusion coefficients of Sn in both growing phases.

An Explanation of the Influence of the Order-Disorder B2-B.C.C Transformation of the Self-Diffusion Behaviour in Alloys

1982 ◽  
Vol 21 ◽  
Author(s):  
H. Bakker
Keyword(s):  
Diffusion Coefficients ◽  
Isotope Effects ◽  
Tracer Diffusion ◽  
The Self ◽  
Disorder Transition ◽  
Self Diffusion ◽  
Kinetics Of ◽  
Diffusion Behaviour

ABSTRACTTheories describing the kinetics of ordered B2 and disordered b.c.c. alloys are applied to the effect of the order-disorder transition on tracer diffusion. Both tracer self-diffusion coefficients and isotope effects in βCuZn and equiatomic FeCo are considered.

scholarly journals Kinetics of the Boride Layers Obtained on AISI 1018 Steel by Considering the Amount of Matter Involved

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 259 ◽  
Author(s):  
Pablo A. Ruiz-Trabolsi ◽  
Julio Cesar Velázquez ◽  
Carlos Orozco-Álvarez ◽  
Rafael Carrera-Espinoza ◽  
Jorge A. Yescas-Hernández ◽  
...  
Keyword(s):  
Sample Size ◽  
Growth Kinetics ◽  
Duration Of Treatment ◽  
Solid Diffusion ◽  
Treatment Conditions ◽  
Wear And Corrosion ◽  
Different Diameters ◽  
Boriding Process ◽  
Kinetics Of ◽  
Cylindrical Samples

Boride layers are typically used to combat the wear and corrosion of metals. For this reason, to improve our knowledge of the boriding process, this research studied the effect of the size of the treated material on the kinetics of the growth of the boride layers obtained during a solid diffusion process. The purpose was to elucidate how the layers’ growth kinetics could be affected by the size of the samples since, as the amount of matter increases, the amount of energy necessary to make the process occur also increases. Furthermore, the level of activation energy seems to change as a function of the sample size, although it is considered an intrinsic parameter of each material. Six cylindrical samples with different diameters were exposed to the boriding process for three different exposure times (1.5, 3, and 5 h). The treatment temperatures used were 900, 950, and 1000 °C for each size and duration of treatment. The results show that the layer thickness increased not only as a function of the treatment conditions but also as a function of the sample diameter. The influence of the sample size on the growth kinetics of the boride layers is clear, because the growth rate increased even though the treatment conditions (time and temperature) remained constant.

The Formation of Cu3Si from Cu/a-Si Multilayers

1997 ◽  
Vol 481 ◽  
Author(s):  
R. R. Chromik ◽  
W. K. Neils ◽  
E. J. Cotts
Keyword(s):  
Diffusion Couples ◽  
X Ray Diffraction ◽  
Limited Growth ◽  
Scanning Calorimetry ◽  
Individual Layer ◽  
Diffusion Limited ◽  
Reaction Constant ◽  
Multilayered Composites ◽  
Reaction Constants ◽  
Kinetics Of

ABSTRACTThe kinetics of the formation of Cu3Si in Cu/a-Si diffusion couples have been investigated by means of differential scanning calorimetry and x-ray diffraction. Multilayered composites of average stoichiometry Cu3Si were prepared by sputter deposition with individual layer thicknesses varying in different samples between 2 and 100 nm. We observed diffusion limited growth of Cu3 Si upon annealing these diffusion couples below 500 K. Reaction constants were measured for a temperature range of 455 to 495 K for thicknesses of growing Cu3Si between 2.6 and 80 nm. The temperature dependence of the reaction constant, k2, was characterized as k2 = k0 exp(− Ea/kbT) with activation energy, Ea = 1.0 eV/atom and pre-factor, k0 = 1.9×10−3 cm2/s.

scholarly journals Structural and Functional Regulation of Tight Junctions by RhoA and Rac1 Small GTPases

1998 ◽  
Vol 142 (1) ◽  
pp. 101-115 ◽  
Author(s):  
Tzuu-Shuh Jou ◽  
Eveline E. Schneeberger ◽  
W. James Nelson
Keyword(s):  
Tight Junctions ◽  
Spatial Organization ◽  
Mdck Cells ◽  
Protein Localization ◽  
Freeze Fracture ◽  
Tracer Diffusion ◽  
Small Gtpases ◽  
Dominant Negative ◽  
Solute Diffusion ◽  
Fence Function

Tight junctions (TJ) govern ion and solute diffusion through the paracellular space (gate function), and restrict mixing of membrane proteins and lipids between membrane domains (fence function) of polarized epithelial cells. We examined roles of the RhoA and Rac1 GTPases in regulating TJ structure and function in MDCK cells using the tetracycline repressible transactivator to regulate RhoAV14, RhoAN19, Rac1V12, and Rac1N17 expression. Both constitutively active and dominant negative RhoA or Rac1 perturbed TJ gate function (transepithelial electrical resistance, tracer diffusion) in a dose-dependent and reversible manner. Freeze-fracture EM and immunofluoresence microscopy revealed abnormal TJ strand morphology and protein (occludin, ZO-1) localization in RhoAV14 and Rac1V12 cells. However, TJ strand morphology and protein localization appeared normal in RhoAN19 and Rac1N17 cells. All mutant GTPases disrupted the fence function of the TJ (interdomain diffusion of a fluorescent lipid), but targeting and organization of a membrane protein in the apical membrane were unaffected. Expression levels and protein complexes of occludin and ZO-1 appeared normal in all mutant cells, although ZO-1 was more readily solubilized from RhoAV14-expressing cells with Triton X-100. These results show that RhoA and Rac1 regulate gate and fence functions of the TJ, and play a role in the spatial organization of TJ proteins at the apex of the lateral membrane.

Investigation of the diffusion behavior in Sn-xAg-yCu/Cu solid state diffusion couples

2016 ◽  
Vol 686 ◽  
pp. 794-802 ◽  
Author(s):  
Yuan Yuan ◽  
Dajian Li ◽  
Yuanyuan Guan ◽  
Hans J. Seifert ◽  
Nele Moelans
Keyword(s):  
Solid State ◽  
Solid State Diffusion ◽  
Diffusion Couples ◽  
Diffusion Behavior ◽  
State Diffusion
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