A study of the suppression of the high-temperature helium embrittlement in an oxide-particle dispersion strengthened alloy

The strengthening effect at high temperature produced by a dispersed oxide phase in a metal matrix is seemingly dependent on at least two major contributors: oxide particle size and spatial distribution, and stability of the worked microstructure. These two are strongly interrelated. The stability of the microstructure is produced by polygonization of the worked structure forming low angle cell boundaries which become anchored by the dispersed oxide particles. The effect of the particles on strength is therefore twofold, in that they stabilize the worked microstructure and also hinder dislocation motion during loading.

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Contactless generation of cavitation in high temperature liquid metals and its impact on particle dispersion in solidified iron and steel samples

Journal of Materials Processing Technology ◽

10.1016/j.jmatprotec.2021.117041 ◽

2021 ◽

Vol 291 ◽

pp. 117041

Author(s):

Mārtiņš Sarma ◽

Ilmārs Grants ◽

Thomas Herrmannsdörfer ◽

Gunter Gerbeth

Keyword(s):

High Temperature ◽

Liquid Metals ◽

Particle Dispersion ◽

Iron And Steel ◽

Temperature Liquid

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Model for the final stage of creep failure due to high temperature helium embrittlement

Journal of Nuclear Materials ◽

10.1016/0022-3115(95)00179-4 ◽

1996 ◽

Vol 233-237 ◽

pp. 1085-1088 ◽

Cited By ~ 7

Author(s):

A. Ryazanov ◽

R.E. Voskoboinikov ◽

H. Trinkaus

Keyword(s):

High Temperature ◽

Final Stage ◽

Creep Failure ◽

Helium Embrittlement

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Aluminum oxide particle optical constant in high temperature

10.1117/12.916964 ◽

2012 ◽

Author(s):

Jinying Yin

Keyword(s):

High Temperature ◽

Aluminum Oxide ◽

Optical Constant ◽

Oxide Particle ◽

Aluminum Oxide Particle

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High temperature helium embrittlement in austenitic stainless steels - correlations between microstructure and mechanical properties

Journal of Nuclear Materials ◽

10.1016/0022-3115(88)90462-x ◽

1988 ◽

Vol 155-157 ◽

pp. 1032-1037 ◽

Cited By ~ 23

Author(s):

Herbert Schroeder

Keyword(s):

Mechanical Properties ◽

High Temperature ◽

Stainless Steels ◽

Austenitic Stainless Steels ◽

Microstructure And Mechanical Properties ◽

Helium Embrittlement

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An investigation of the peculiarities of high-speed sintering of plasma chemically synthesized tungsten carbide nanopowders with increased oxygen content

Physics and Chemistry of Materials Treatment ◽

10.30791/0015-3214-2020-6-23-39 ◽

2020 ◽

Vol 6 ◽

pp. 23-39

Author(s):

Е.А. Lantsev ◽

◽

N.V. Malekhonova ◽

Yu.V. Tsvetkov ◽

Yu.V. Blagoveshchensky ◽

...

Keyword(s):

High Temperature ◽

Tungsten Carbide ◽

Oxygen Content ◽

High Speed ◽

Oxide Particle ◽

High Oxygen Content ◽

Plasma Sintering ◽

Ultrafine Grained ◽

Average Grain Size ◽

Spark Plasma

Spark plasma sintering (SPS) of plasma-chemical nanopowders tungsten carbide with a high oxygen content are studied. The results show that the nanopowder WC shrinkages during SPS is limited by grain boundary diffusion with abnormally low activation energies. It is established that the decrease in the activation energy can be caused by the influence of oxygen on the diffusion permeability of the tungsten carbide grain boundaries at the stage of intense compaction, as well as by abnormal grain growth at the stage of high-temperature sintering. The SPS kinetics of WC-W2C-WO3-W nanopowder compositions at the stage of intense compaction is controlled by the rate of oxide particle sintering with their simultaneous transformation into W2C particles, and then, by the plastic flow of W2C particles in the presence of W particles at the stage of high-temperature sintering. Using the SPS method, we obtained ceramics with a high density (98-99%), ultrafine-grained structure (the average grain size is less than 0.3 mm), having an increased hardness HV = 30.5 GPa with a Palmquist crack resistance of ~6.5 MPa·m1/2.

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Compocasting of an Al-Si-SiCp Composite Using Powder Injection Method

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.141-143.175 ◽

2008 ◽

Vol 141-143 ◽

pp. 175-180 ◽

Cited By ~ 10

Author(s):

M. Ghahremainian ◽

Behzad Niroumand

Keyword(s):

High Temperature ◽

Solid Fraction ◽

Composite Powder ◽

Particulate Composite ◽

Particle Dispersion ◽

Powder Injection ◽

Injection Method ◽

Speed Up ◽

Magnesium Addition

In this work Al-7wt%Si-10wt%SiCp composites were produced by injection of the reinforcement in the form of SiCp particles or a specially made particulate composite powder of aluminum and SiCp into the melt of proper composition at a temperature corresponding to 10% solid fraction. This paper presents the results of the investigation on the effects of reinforcement addition form, reinforcement addition temperature, stirring speed and magnesium addition on the incorporation and distribution of the reinforcement particles. The results showed that incorporation of SiCp particles was considerably improved by their injection in the form of milled Al/SiCp composite powder. Better particle wetting, improved particle dispersion and reduced particles size were achieved by injection of milled Al/SiCp composite powder instead of SiCp powder. Magnesium addition and high temperature injection were necessary for achieving good incorporation. Reinforcement incorporation was improved by increasing the stirring speed up to 500 rpm, after which the incorporation decreased slowly.

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