Dispersion Strengthening by Solidification

1996 ◽  
pp. 281-315
Author(s):  
Donald R. Askeland
Keyword(s):  
Dispersion Strengthening

Dislocation structures around SiO2 Particles in aged Cu-Cr-SiO2

1978 ◽  
Vol 36 (1) ◽  
pp. 594-595
Author(s):  
N.J. Long ◽  
M.H. Loretto ◽  
C.H. Lloyd
Keyword(s):  
Flow Stress ◽  
Single Crystals ◽  
Room Temperature ◽  
Thin Foil ◽  
Age Hardening ◽  
Dispersion Strengthening ◽  
Accurate Picture ◽  
The Matrix ◽  
Very High ◽  
Good Agreement

IntroductionThere have been several t.e.m. studies (1,2,3,4) of the dislocation arrangements in the matrix and around the particles in dispersion strengthened single crystals deformed in single slip. Good agreement has been obtained in general between the observed structures and the various theories for the flow stress and work hardening of this class of alloy. There has been though some difficulty in obtaining an accurate picture of these arrangements in the case when the obstacles are large (of the order of several 1000's Å). This is due to both the physical loss of dislocations from the thin foil in its preparation and to rearrangement of the structure on unloading and standing at room temperature under the influence of the very high localised stresses in the vicinity of the particles (2,3).This contribution presents part of a study of the Cu-Cr-SiO2 system where age hardening from the Cu-Cr and dispersion strengthening from Cu-Sio2 is combined.

scholarly journals ODS EUROFER Steel Strengthened by Y-(Ce, Hf, La, Sc, and Zr) Complex Oxides

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1148 ◽  
Author(s):  
Roman Husák ◽  
Hynek Hadraba ◽  
Zdeněk Chlup ◽  
Milan Heczko ◽  
Tomáš Kruml ◽  
...  
Keyword(s):  
Grain Size ◽  
Yield Strength ◽  
Complex Oxides ◽  
Oxide Dispersion Strengthened ◽  
Interparticle Spacing ◽  
Oxide Dispersion ◽  
Strengthening Effect ◽  
Dispersion Strengthening ◽  
Doping Element ◽  
Average Grain Size

Oxide dispersion-strengthened (ODS) materials contain homogeneous dispersions of temperature-stable nano-oxides serving as obstacles for dislocations and further pinning of grain boundaries. The strategy for dispersion strengthening based on complex oxides (Y-Hf, -Zr, -Ce, -La) was developed in order to refine oxide dispersion to enhance the dispersion strengthening effect. In this work, the strengthening of EUROFER steel by complex oxides based on Y and elements of the IIIB group (lanthanum, scandium) and IVB group (cerium, hafnium, zirconium) was explored. Interparticle spacing as a dispersoid characteristic appeared to be an important factor in controlling the dispersion strengthening contribution to the yield strength of ODS EUROFER steels. The dispersoid size and average grain size of ODS EUROFER steel were altered in the ranges of 5–13 nm and 0.6–1.7 µm, respectively. Using this strategy, the yield strength of the prepared alloys varied between 550 MPa and 950 MPa depending on the doping element.

scholarly journals Investigation of the microstructure evolution in TP347HFG austenitic steel at 700°C and its characterization method

2021 ◽  
Vol 40 (1) ◽  
pp. 12-22
Author(s):  
Yuetao Zhang ◽  
Tingbi Yuan ◽  
Yawei Shao ◽  
Xiao Wang
Keyword(s):  
Austenitic Steel ◽  
Aging Time ◽  
Microstructure Evolution ◽  
Precipitate Phase ◽  
Dispersion Strengthening ◽  
Micro Hardness ◽  
Dispersed Particles ◽  
Nonlinear Ultrasonic ◽  
The Matrix ◽  
Solution Strengthening

Abstract This article reports the microstructure evolution in TP347HFG austenitic steel during the aging process. The experiments were carried out at 700°C with different aging time from 500 to 3,650 h. The metallographic results show that the coherent twin and incoherent twin are existed in the original TP347HFG grains, while they gradually vanished with the increase of the aging time. After aging for 500 h, a lot of fine, dispersed particles precipitated from the matrix, but they disappeared after aging for 1,500 h. When the aging time extend to 3,650 h, the precipitates appeared apparently coarse in TP347HFG steel, which include the M23C6 and σ phase; besides, the micro-hardness of TP347HFG also changes during the aging, which was closely related to the effect of dispersion strengthening and solution strengthening. The results of the nonlinear ultrasonic measurement reveal that the β′ of TP347HFG steel was also changed with the aging time. It first increased at 0–500 h, then reduced later, and increased finally at 1,500–3,650 h. The variation of β′ in TP347HFG was influenced by a combined effect of the twin microstructure and the precipitate phase, which indicate that the nonlinear ultrasonic technique can be utilized to characterize the microstructure evolution in TP347HFG.

Dispersion strengthening of high-strength steel 34KhN3MF

1986 ◽  
Vol 18 (11) ◽  
pp. 1497-1499
Author(s):  
S. A. Gladyshev ◽  
A. I. Skvortsov ◽  
V. M. Kondratov
Keyword(s):  
High Strength Steel ◽  
High Strength ◽  
Dispersion Strengthening

Fabrication of Cu-Al2O3 Composites by Simplified Internal Oxidation Process

2010 ◽  
Vol 148-149 ◽  
pp. 416-419
Author(s):  
Bao Hong Tian ◽  
Cheng Dong Xia ◽  
Shu Guo Jia
Keyword(s):  
Electrical Conductivity ◽  
Tensile Strength ◽  
Internal Oxidation ◽  
Oxidation Process ◽  
Hot Extrusion ◽  
Softening Temperature ◽  
Copper Matrix ◽  
Dispersion Strengthening ◽  
Powder Metallurgical Process ◽  
Thermal Stability Of

Cu-Al2O3 composites were prepared by a new simplified internal oxidation process integrating with powder metallurgical process, and then the hot extrusion and the cold rolling processes were carried out. The microstructure, electrical conductivity, hardness, tensile strength and thermal stability of the composites were investigated. The results show that Cu-Al2O3 composites were fabricated successfully by the simplified process in which internal oxidation completed during the sintering. There are a mass of fine Al2O3 particles in size varying from 5 nm to 20nm dispersed in copper matrix after sintering 950 for 4h. After sintered at 950 for 4h and extruded at 950 followed with the cold deforming of 80%, the electrical conductivity, hardness, tensile strength and softening temperature of composite reach 81％IACS, 137HV, 561MPa and 850 respectively. It is considered that the dispersion strengthening and strain hardening have greatly contribution to the Cu-Al2O3 composites fabricated with the simplified process.

scholarly journals Performance of wear resistant MCrAlY coatings with oxide dispersion strengthening

Wear ◽  
2020 ◽  
Vol 444-445 ◽  
pp. 203116
Author(s):  
Giovanni Bolelli ◽  
Christoph Vorkötter ◽  
Luca Lusvarghi ◽  
Stefania Morelli ◽  
Veronica Testa ◽  
...  
Keyword(s):  
Oxide Dispersion ◽  
Dispersion Strengthening ◽  
Oxide Dispersion Strengthening ◽  
Wear Resistant ◽  
Mcraly Coatings
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