Fe+ Implantation Induced Damage in Oxide Dispersion Strengthened Steels Investigated by Doppler Broadening Spectroscopy

2017 ◽  
Vol 373 ◽  
pp. 113-116 ◽  
Author(s):  
Wolfgang Anwand ◽  
Teresa Leguey ◽  
Masa Scepanovic ◽  
Fernando Jose Sanchez ◽  
Isabel García-Cortés ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Line Shape ◽  
Oxide Dispersion Strengthened ◽  
Positron Annihilation Spectroscopy ◽  
Oxide Dispersion ◽  
Doppler Broadening ◽  
Shape Parameters ◽  
Before And After ◽  
Oxide Particles ◽  
Coincidence Doppler Broadening

Open volume defects created by 1 MeV Fe+ implantation up to a damage of 15 displacements per atom into Fe14wt%Cr and into oxide dispersion strengthened (ODS) Fe14wt%Cr were investigated by positron annihilation spectroscopy, especially single Doppler broadening (DBS) and coincidence Doppler broadening spectroscopies (cDBS). The influence of W and Ti alloying elements on the evolution of defects during ion implantation were probed in addition. Whereas no effect of the W and Ti alloying constituents on the line-shape parameters S and W could be detected both before and after ion implantation, fine dispersed Y2O3 particles showed important changes in the structural properties compared to pure FeCr steel, which could be detected by DBS and cDBS. The distribution of the electron momenta in implanted ODS Fe14Cr, obtained with cDBS, shows that oxide particles form obstacles for expanded vacancy mobility and that the vacancies are localized around the oxide particles.

scholarly journals Growth of oxide particles in FeCrAl- oxide dispersion strengthened steels at high temperature

2017 ◽  
Vol 493 ◽  
pp. 180-188 ◽  
Author(s):  
N.H. Oono ◽  
S. Ukai ◽  
S. Hayashi ◽  
S. Ohtsuka ◽  
T. Kaito ◽  
...  
Keyword(s):  
High Temperature ◽  
Oxide Dispersion Strengthened ◽  
Oxide Dispersion ◽  
Oxide Particles

Y2O3 Morphology in an Oxide Dispersion Strengthened FeAl Alloy Prepared by Mechanical Alloying

1996 ◽  
Vol 460 ◽  
Author(s):  
B. J. Inkson ◽  
P. L. Threadgill
Keyword(s):  
Mechanical Alloying ◽  
Oxide Dispersion Strengthened ◽  
Oxide Dispersion ◽  
Feal Alloy ◽  
Oxide Particles

ABSTRACTThe microstructure of an oxide dispersion strengthened FeAl (Zr,B) alloy, manufactured by mechanical alloying then extrusion, has been examined by HREM. Y2O3 is dispersed throughout the FeAl matrix as particles, ranging in size from 5nm upwards, which are effective in pinning the bulk dislocations. Although in the main the observed oxide particles are irregular in morphology, a significant minority of particles exhibit faceted surfaces. In particular, the facets of the Y2O3 particles are observed to coincide with {100}B2, {110}B2 and {112}B2 planes of the surrounding bulk FeAl matrix. In addition, HREM imaging reveals uncoupled 1/2<111>FeAl superpartial dislocations lying a few nanometres from some of the FeAl - Y2O3 interfaces.

Excessive ThO2 Particle Growth in Ni-2ThO2 at High Temperature

1970 ◽  
Vol 28 ◽  
pp. 416-417
Author(s):  
E. R. Kimmel ◽  
H. L. Anthony ◽  
W. Scheithauer
Keyword(s):  
Particle Size ◽  
Metal Matrix ◽  
Oxide Dispersion Strengthened ◽  
Particle Growth ◽  
Interparticle Spacing ◽  
Refractory Oxide ◽  
Oxide Dispersion ◽  
Volume Percent ◽  
Oxide Particles ◽  
Cold Worked

It is generally accepted that a uniform spatial distribution of fine refractory oxide particles is required in an oxide-dispersion-strengthened metal to provide good elevated-temperature strengths. The presence of these particles stabilizes the cold-worked microstructure by anchoring low-angle cell boundaries and by restricting the motion of dislocations during loading. Such action by the particles must be a function of the interparticle spacing as is proposed by the Orowan model for yield stress. For a given volume percent of oxide in the metal matrix, the interparticle spacing is directly proportional to the particle size. Therefore, particle growth during the processing of oxide-dispersion-strengthened metals increases the interparticle spacing and inherently decreases the strength.

TEM and HRTEM study of oxide particles in an Al-alloyed high-Cr oxide dispersion strengthened steel with Zr addition

2014 ◽  
Vol 444 (1-3) ◽  
pp. 441-453 ◽  
Author(s):  
Peng Dou ◽  
Akihiko Kimura ◽  
Ryuta Kasada ◽  
Takanari Okuda ◽  
Masaki Inoue ◽  
...  
Keyword(s):  
Oxide Dispersion Strengthened ◽  
Oxide Dispersion ◽  
Oxide Dispersion Strengthened Steel ◽  
Zr Addition ◽  
Oxide Particles

Oxidation of Oxide Dispersion Strengthened Steels: II. Kinetics and Mechanism

2013 ◽  
Vol 748 ◽  
pp. 106-111
Author(s):  
Jae Hoon Lee
Keyword(s):  
Grain Refinement ◽  
Oxidation Resistance ◽  
Oxide Dispersion Strengthened ◽  
Oxide Dispersion ◽  
Protective Oxide ◽  
Alumina Layer ◽  
Ods Steel ◽  
Time Period ◽  
Oxide Particles ◽  
Ods Steels

The oxidation resistance of 18%Cr-oxide dispersion strengthened (ODS) ferritic steels with and without 5%Al has been investigated in air at 700900 °C for time period up to 540 h. The oxidation rate of ODS steels is significantly dependent on the oxidation time and temperature. Compared to Al-containing ODS steel, the finer grains of Al-free ODS steel are due to the formation of smaller coherent oxide particles which suppress the steel's grain growth. The grain refinement of ODS steels is expected to allow rapid segregation of Cr or Al to the steel surface, so that the continuous Fe-Cr spinel or alumina layer is formed quickly in comparison to the alloys without oxide particles dispersion. Therefore, the excellent oxidation resistance of ODS steels is owing to the formation of continuous, protective oxide layers which correlate with oxide nanoparticles and grain refinement.

scholarly journals Vacuum Hot Pressing of Oxide Dispersion Strengthened Ferritic Stainless Steels: Effect of Al Addition on the Microstructure and Properties

2020 ◽  
Vol 4 (3) ◽  
pp. 93
Author(s):  
Dharmalingam Ganesan ◽  
Prabhukumar Sellamuthu ◽  
Konda Gokuldoss Prashanth
Keyword(s):  
Stainless Steel ◽  
Stainless Steels ◽  
Hot Pressing ◽  
Crucial Role ◽  
Ostwald Ripening ◽  
Oxide Dispersion Strengthened ◽  
Oxide Dispersion ◽  
Ferritic Stainless Steels ◽  
Oxide Particles ◽  
Ods Alloys

The present article investigates the fabrication of oxide dispersion strengthened (ODS) ferritic stainless steel (FSS). Three different ODS alloys with three different Al contents were fabricated, where the presence of Al-based oxides play a crucial role in determining the size of the oxide particles. Due to Ostwald ripening, the samples with Al show coarser oxide particles compared to the alloy without Al, which hampers the density of the fabricated samples and, hence, have reduced hardness levels. The present results suggest that the composition of the oxide present in ODS plays a crucial role in determining the properties of these samples.

scholarly journals Production of Oxide Dispersion Strengthened Mg-Zn-Y Alloy by Equal Channel Angular Pressing of Mechanically Alloyed Powder

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 679 ◽  
Author(s):  
Keng-Liang Ou ◽  
Chia-Chun Chen ◽  
Chun Chiu
Keyword(s):  
Equal Channel Angular Pressing ◽  
Oxide Dispersion Strengthened ◽  
Oxide Dispersion ◽  
Dispersion Strengthening ◽  
Mechanically Alloyed ◽  
Angular Pressing ◽  
Lpso Structure ◽  
Gas Atmosphere ◽  
Solution Strengthening ◽  
Oxide Particles

Mg-Zn-Y alloys with long-period stacking ordered structures (LPSO) have attracted attention due to their excellent mechanical properties. In addition to the LPSO structure, Mg alloys can also be strengthened by oxide particles. In the present study, oxide dispersion strengthened Mg97Zn1Y2 (at%) alloys were prepared by equal channel angular pressing (ECAP) of mechanical alloyed (MA) powder under an oxygen gas atmosphere. The 20-h-MA powder had a particle size of 28 μm and a crystallite size of 36 nm. During the MA process followed by ECAP, an Mg matrix with dispersed Y2O3 (and MgO) particles was formed. The alloy processed by ECAP exhibited a hardness of 110 HV and a compressive strength of 185 MPa. Compared to pure Mg, the increased hardness was due to the dispersion strengthening of Y2O3 and MgO particles and solution strengthening of Zn and Y.

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