Effect of cold deformation on kinetics of solid solution decomposition and accompanying transformation in structure

An influence of Cd content on the kinetics of a spontaneous low-temperature structure transformation in In-rich In - Cd alloys has been investigated using acoustic, resistivity and DSCtechniques. It is established that increase of the concentration of Cd leads to an essential increase of a driving force of the transition that results in an increase of the transition rate and in decrease of the relaxation time. The low-temperature instability of acoustic, resistivity and thermal properties is caused presumably by a decomposition of the solid solution that has features of a phase transition of the 1st order. The main empirical activation parameters of the transformation are derived. The activation energy amounts to U0 = 0.43 eV, the attempt period is τ 0 =5 × 10-9 s. The probable border of the decomposition in the phase diagram of the In-Cd system is established.

Download Full-text

Low Temperature Kinetics of In-Cd Solid Solution Decomposition

Solid State Phenomena - Interaction between Defects and Anelastic Phenomena in Solids ◽

10.4028/3-908451-53-1.35 ◽

2008 ◽

pp. 35-42

Author(s):

P.P. Pal-Val ◽

L.N. Pal-Val ◽

A.A. Ostapovets ◽

P. Vanek

Keyword(s):

Solid Solution ◽

Low Temperature ◽

Solid Solution Decomposition ◽

Low Temperature Kinetics ◽

Kinetics Of

Download Full-text

Solid solution decomposition and Guinier-Preston zone formation in Al-Cu alloys: A kinetic theory with anisotropic interactions

Physical Review Materials ◽

10.1103/physrevmaterials.2.033603 ◽

2018 ◽

Vol 2 (3) ◽

Cited By ~ 4

Author(s):

A. Yu. Stroev ◽

O. I. Gorbatov ◽

Yu. N. Gornostyrev ◽

P. A. Korzhavyi

Keyword(s):

Solid Solution ◽

Kinetic Theory ◽

Zone Formation ◽

Cu Alloys ◽

Solid Solution Decomposition ◽

Anisotropic Interactions ◽

Guinier Preston Zone

Download Full-text

Oxidation behavior of non-stoichiometric (Zr,Hf,Ti)Cx carbide solid solution powders in air

Journal of Advanced Ceramics ◽

10.1007/s40145-021-0469-y ◽

2021 ◽

Author(s):

Huilin Lun ◽

Yi Zeng ◽

Xiang Xiong ◽

Ziming Ye ◽

Zhongwei Zhang ◽

...

Keyword(s):

Solid Solution ◽

Oxidation Resistance ◽

Oxidation Behavior ◽

Group Iv ◽

Hypersonic Vehicles ◽

Metal Carbides ◽

Initial Oxidation ◽

Plasma Sintering ◽

Spark Plasma ◽

Kinetics Of

AbstractMulti-component solid solutions with non-stoichiometric compositions are characteristics of ultra-high temperature carbides as promising materials for hypersonic vehicles. However, for group IV transition-metal carbides, the oxidation behavior of multi-component non-stoichiometric (Zr,Hf,Ti)Cx carbide solid solution has not been clarified yet. The present work fabricated four kinds of (Zr,Hf,Ti)Cx carbide solid solution powders by free-pressureless spark plasma sintering to investigate the oxidation behavior of (Zr,Hf,Ti)Cx in air. The effects of metallic atom composition on oxidation resistance were examined. The results indicate that the oxidation kinetics of (Zr,Hf,Ti)Cx are composition dependent. A high Hf content in (Zr,Hf,Ti)Cx was beneficial to form an amorphous Zr-Hf-Ti-C-O oxycarbide layer as an oxygen barrier to enhance the initial oxidation resistance. Meanwhile, an equiatomic ratio of metallic atoms reduced the growth rate of (Zr,Hf,Ti)O2 oxide, increasing its phase stability at high temperatures, which improved the oxidation activation energy of (Zr, Hf, Ti)Cx.

Download Full-text

Al, Cu and Zr Addition to High Entropy Alloys: The Effect on Recrystallization Temperature

Materials Science Forum ◽

10.4028/www.scientific.net/msf.941.1137 ◽

2018 ◽

Vol 941 ◽

pp. 1137-1142

Author(s):

Elena Colombini ◽

Andrea Garzoni ◽

Roberto Giovanardi ◽

Paolo Veronesi ◽

Angelo Casagrande

Keyword(s):

Solid Solution ◽

Grain Size ◽

Single Phase ◽

Boundary Energy ◽

Cold Deformation ◽

Recrystallization Temperature ◽

High Entropy Alloys ◽

High Entropy ◽

Ni Alloy ◽

Sluggish Diffusion

The equimolar Cr, Mn, Fe, Co and Ni alloy, first produced in 2004, was unexpectedly found to be single-phase. Consequently, a new concept of materials was developed: high entropy alloys (HEA) forming a single solid-solution with a near equiatomic composition of the constituting elements. In this study, an equimolar CoCrFeMnNi HEA was modified by the addition of 5 at% of either Al, Cu or Zr. The cold-rolled alloys were annealed for 30 minutes at high temperature to investigate the recrystallization kinetics. The evolution of the grain boundary and the grain size were investigated, from the as-cast to the recrystallized state. Results show that the recrystallized single phase FCC structures exhibits different twin grains density, grain size and recrystallization temperatures as a function of the at.% of modifier alloying elements added. In comparison to the equimolar CoCrFeMnNi, the addition of modifier elements increases significantly the recrystallization temperature after cold deformation. The sluggish diffusion (typical of HEA alloys), the presence of a solute in solid solution as well as the low twin boundary energy are responsible for the lower driving force for recrystallization.

Download Full-text