Two processes in the kinetics of short-range ordering and disordering in Cu-15 at% Al

Veith, Gabriel M.; Trieb, L.; Püschl, Wolfgang; Aubauer, H. P.

doi:10.1002/pssa.2210270107

Cited by 28 publications

(7 citation statements)

References 27 publications

(2 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2, give 146/151/171 kJ tool -1 for 19/13/6.5 at % A1 alloys. These values agree reasonably well with those for self-diffusion reported in the literature [32][33][34][35][36].…”

Section: Kinetic Analysissupporting

confidence: 91%

Ordered domain characterization in α-Cu-Al alloys from dissolution kinetics studies

Varschavsky

Donoso

1986

J Mater Sci

View full text Add to dashboard Cite

Through microcalorimetric experiments, disperse order (DO) dissolution kinetics in preannealed e-Cu-AI alloys containing 1 9, 13 and 6.5 at% aluminium were adequately described by the integrated kinetic model function arising from the steady-state part of the diffusion field: f(y) = 1 -(1 -y)2/3. Domain sizes after the annealing treatment, and also critical radii, were determined from differential scanning calorimetry data analysis at different heating rates. The existence of critical radii indicates that the disperse-order dissolution process is a firstorder transition. Nevertheless, it was inferred that for very dilute alloys, only short-range order is present. After pre-annealing the alloys at different temperatures, volume fractions and domain concentrations were computed by employing the above kinetic model under high heating-rate conditions. On the basis of appropriate time constant and diffusion time calculations, the range of such temperatures compatible with equilibrium attainment was established. Prolonged pre-anneals alter the particle distribution, but do not influence either volume fractions or domain sizes. A semi-quantitative particle radius-particle concentration-temperature diagram was proposed for e-Cu-AI alloys.

show abstract

“…2, give 146/151/171 kJ tool -1 for 19/13/6.5 at % A1 alloys. These values agree reasonably well with those for self-diffusion reported in the literature [32][33][34][35][36].…”

Section: Kinetic Analysissupporting

confidence: 91%

Ordered domain characterization in α-Cu-Al alloys from dissolution kinetics studies

Varschavsky

Donoso

1986

J Mater Sci

View full text Add to dashboard Cite

show abstract

“…A numerical solution of this equation in Section 6 enables a discussion of the kinetic behaviour with different initial and final states and different energy expressions in Section 7 : It follows that the kinetics of transitions between one-phase states and that from a one-to a two-phase state differ qualitatively from those between two-phase states. I n the latter case two processes with distinctly different rates evolve, that have already been observed experimentally [5,2]. The results of this work agree excellently with those of a simpler, but transparent special model [5] of stable heterogeneous system kinetics.…”

Section: Introductionsupporting

confidence: 84%

“…I n the latter case two processes with distinctly different rates evolve, that have already been observed experimentally [5,2]. The results of this work agree excellently with those of a simpler, but transparent special model [5] of stable heterogeneous system kinetics.…”

Section: Introductionsupporting

confidence: 84%

The Kinetics of Stable Heterogeneous Binary Systems

Püschl¹,

Aubauer²

1980

Physica Status Solidi (b)

Self Cite

View full text Add to dashboard Cite

Among thermodynamically stable systems homogeneous one-phase states are compared with two-phase heterogeneous ones, while no restriction is made about the physical origin of stability. In the case of transitions from a one-phase state t o another one-phaee state or a two-phase system, a continuous spectrum of relaxation times appears as a difference to a transition from a two-phase t o another two-phase state: in this latter case one finds two processes of distinctly different rates in good agreement, with experiment. With the aid of a stochastic theory, containing elements of classical nucleation and coarsening theory, the early, as well as the late kinetic change of the size distribution function as well as of momenta, describing the system, are derived. This theory also allows for a rise of the number of zones of a phase during annealing as a contrary effect to coarsening.

show abstract

“…where the activation energy for pipe diffusion Qp was taken similar to that of grain boundary diffusion [ 11] which in turn is a little more than half of that for volume diffusion Ob ~ 162.8 kJ mo1-1 [28]. On the other hand, the pre-exponential factor of Dp, can be taken from lattice diffusion Dop=Dob=6.68xl 0 -s m2s -1 [29].…”

Section: Discussionmentioning

confidence: 99%

“…For instance, at 530 K, which is the higher temperature employed in isothermal previous work, one obtains in principle D/Du=l.57xl 0 thus making very hkely that most of the diffusion takes place along dislocations. The activation energy for pipe diffusion was estimated as Qp=81.4 kJ mo1-1 [28]. However, if the binding energy is not negligible, then the solute can change the pipe structure, for example fill in open spaces and make it harder for atoms to move along the dislocations (pinner effects).…”

Section: Discussionmentioning

confidence: 99%

Modelling the kinetics of solute segregation to partial dislocations for isothermal microcalorimetric evaluations

Varschavsky

Donoso

1997

Journal of Thermal Analysis

View full text Add to dashboard Cite

A model is proposed to describe the kinetics of solute segregation to partial dislocations in solid solutions of cold-rolled alloys. The case when half edge and half screw dislocations are present is considered. The model gives account of the kinetic behaviour observed in a deformed Cu-19 at% A1 alloy where two unknown processes could be assessed during calorimetric isothermal experiments. The faster process corresponds to segregation to screw dissociated dislocations while the slower one corresponds to segregation to edge dissociated dislocations Experimental activation energies, larger for edge dislocations, are close to that for pipe dif'fhsion along the partials corrected by pinner binding energy terms. It is also predicted that segregation occurs faster as the dislocation density is increased. A quantitative comparison of experimental results with model predictions is given.

show abstract

Two processes in the kinetics of short-range ordering and disordering in Cu-15 at% Al

Cited by 28 publications

References 27 publications

Ordered domain characterization in α-Cu-Al alloys from dissolution kinetics studies

Ordered domain characterization in α-Cu-Al alloys from dissolution kinetics studies

The Kinetics of Stable Heterogeneous Binary Systems

Modelling the kinetics of solute segregation to partial dislocations for isothermal microcalorimetric evaluations

Contact Info

Product

Resources

About