Sensitivity of thermo-electric power measurements to α–α′ phase separation in Cr-rich oxide dispersion strengthened steels

ABSTRACTThe intermetallic compound RuAl2 with Nowotny chimney-ladder structure is synthesized using arc melting technique. The electrical resistity and thermo electric power measurements were carried out in the temperature range 300–1000K. The resistivity increases with increasing temperature and reaches a maximum value at about 700K. Thermo electric power (TEP) of the sample is negative and the value is about -80 µV/K at RT. The value increases with increasing temperature reaching a maximum value of -140 µV/K at about 600K. The compound exhibits temperature independent power factor in the temperature range 300–550K The calculated figure of merit 1.3 × K-1 is comparable to 7 × 10-4 K-1 of Si-Ge alloys which are used as high temperature thermoelectric materials.

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Influence of recrystallization on phase separation kinetics of oxide dispersion strengthened Fe–Cr–Al alloy

Scripta Materialia ◽

10.1016/j.scriptamat.2011.11.003 ◽

2012 ◽

Vol 66 (5) ◽

pp. 254-257 ◽

Cited By ~ 18

Author(s):

C. Capdevila ◽

M.K. Miller ◽

G. Pimentel ◽

J. Chao

Keyword(s):

Phase Separation ◽

Oxide Dispersion Strengthened ◽

Al Alloy ◽

Oxide Dispersion ◽

Phase Separation Kinetics ◽

Kinetics Of ◽

Separation Kinetics

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Conductivity and Thermo-Electric Power Measurements in Trigonal Selenium

physica status solidi (b) ◽

10.1002/pssb.2220460155 ◽

1971 ◽

Vol 46 (1) ◽

pp. K35-K38 ◽

Cited By ~ 3

Author(s):

C. Lemercier

Keyword(s):

Electric Power ◽

Thermo Electric ◽

Power Measurements

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The β'-α' Interaction: a Study of early Stages of Phase Separation in a Fe-20%Cr-6%Al-0.5%Ti Alloy

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.172-174.315 ◽

2011 ◽

Vol 172-174 ◽

pp. 315-320

Author(s):

Carlos Capdevila ◽

Michael K. Miller ◽

K.F. Russell ◽

J. Chao ◽

F.A. López

Keyword(s):

Phase Separation ◽

Atom Probe Tomography ◽

Temporal Evolution ◽

Theoretical Calculations ◽

Three Dimensional ◽

Atom Probe ◽

Early Stages ◽

Β Phase ◽

Α Phase ◽

Power Measurements

The temporal evolution of the microstructure resulting from phase separation into Fe-rich (α), Cr-rich (α¢), and Fe(Ti,Al) (β¢) phases of a Fe-20Cr-6Al-0.5Ti alloy has been analyzed by thermoelectric power measurements (TEP). The early stages of decomposition and the evolution of the three-dimensional microstructure have been analyzed by atom probe tomography (APT). The roles of Cr, Al, and Ti during the decomposition process have been investigated in terms of solute partitioning between the phases. Analysis of proximity histograms revealed that significant Al and Ti partitioning occurs, which is consistent with theoretical calculations. The results indicate that as the α-α¢ phase separation proceeds, Al and Ti are rejected into the α phase, which causes the β¢ phase to nucleate on the surface of the α¢ phase.

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Fine Microstructure of a Mechanically Alloyed Oxide Dispersion Strengthened Nickel-Base Superalloy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100079012 ◽

1977 ◽

Vol 35 ◽

pp. 298-299

Author(s):

Jordi Marti ◽

Timothy E. Howson ◽

David Kratz ◽

John K. Tien

Keyword(s):

Solid Solution ◽

Volume Fraction ◽

Stress Rupture ◽

Oxide Dispersion Strengthened ◽

Solid Solution Alloy ◽

Oxide Dispersion ◽

Creep And Stress Rupture ◽

Mechanically Alloyed ◽

Fine Microstructure ◽

Nickel Base

The previous paper briefly described the fine microstructure of a mechanically alloyed oxide dispersion strengthened nickel-base solid solution. This note examines the fine microstructure of another mechanically alloyed system. This alloy differs from the one described previously in that it is more generously endowed with coherent precipitate γ forming elements A1 and Ti and it contains a higher volume fraction of the finely dispersed Y2O3 oxide. An interesting question to answer in the comparative study of the creep and stress rupture of these two ODS systems is the role of the precipitate γ' in the mechanisms of creep and stress rupture in alloys already containing oxide dispersoids.The nominal chemical composition of this alloy is Ni - 20%Cr - 2.5%Ti - 1.5% A1 - 1.3%Y203 by weight. The system receives a three stage heat treatment-- the first designed to produce a coarse grain structure similar to the solid solution alloy but with a smaller grain aspect ratio of about ten.

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