scholarly journals Comparison of Particle Dispersion Strengthening Estimated by Orowan Model and Ashby-Orowan Model

2021 ◽  
Vol 107 (8) ◽  
pp. 687-691
Author(s):  
Setsuo Takaki ◽  
Masahiro Tsukahara
Keyword(s):  
Particle Dispersion ◽  
Dispersion Strengthening

scholarly journals Effects of Zirconium and Yttrium Oxide on Mechanical and Oxidation Properties of Mo–3Si–1B–1Zr–1Y2O3 (wt.%) Alloy

Coatings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 833
Author(s):  
Zhenping Guo ◽  
Lei Wang ◽  
Cheng Wang ◽  
Qiuliang Li
Keyword(s):  
Fracture Toughness ◽  
Oxidation Resistance ◽  
Yttrium Oxide ◽  
Particle Dispersion ◽  
Second Phase ◽  
Fracture Toughness Test ◽  
Dispersion Strengthening ◽  
Fine Grain ◽  
Fine Grain Strengthening ◽  
Second Phase Particles

Mo–3Si–1B alloys with zirconium (1 wt.%) and yttrium oxide (1 wt.%) additives were fabricated by vibrating sintering techniques. The doped Mo–3Si–1B alloys consisted mainly of α-Mo, Mo3Si, and Mo5SiB2 (T2) phases. It was found that the grains were reduced, and the intermetallics particles were dispersed more homogeneously after the addition of Zr and Y2O3. The optimization in microstructure induced corresponding improvements in both fracture toughness and oxidation resistance. The predominant strengthening mechanisms were fine-grain strengthening and particle dispersion strengthening. In addition, fracture toughness test showed that the additions could improve the toughness of Mo–3Si–1B alloys, for which the toughening mechanism involved a crack trapping by α-Mo phases and extensive small second phase particles in the alloys. What should be paid attention to is the satisfactory oxidation resistance, both at medium-low temperature (800 °C) and high temperature (1200 °C) with doped additives.

Effect of Operating Temperature on Direct Recycling Aluminium Chips (AA6061) in Hot Press Forging Process

2013 ◽  
Vol 315 ◽  
pp. 728-732 ◽  
Author(s):  
N.K. Yusuf ◽  
Mohd Amri Lajis ◽  
M.I. Daud ◽  
Mohamad Zaky Noh
Keyword(s):  
Mechanical Properties ◽  
Operating Temperature ◽  
Strength Properties ◽  
Particle Dispersion ◽  
Dispersion Strengthening ◽  
Hot Press ◽  
Forging Process ◽  
Aa6061 Aluminium Alloy ◽  
Good Potential ◽  
Grain Refinement Strengthening

A method of solid-state recycling aluminum alloy using hot press forging process was studied as well as the possibility of the recycled chip to be used as secondary resources. This paper presents the results of recycled AA6061 aluminium alloy chip using different operating temperature for hot press forging process. Mechanical properties and microstructure of the recycled specimens and as-received (reference) specimen were investigated. The recycled specimens exhibit a good potential in the strength properties. The result for yield strength (YS) and ultimate tensile strength (UTS) at the minimum temperature 430°C is 25.8 MPa and 27.13 MPa. For the maximum operating temperature 520°C YS and UTS are 107.0MPa and 117.53 MPa. Analysis for different operating temperatures shows that the higher temperatures giving better result on mechanical properties and finer microstructure. The strength of recycled specimen increases due to the grain refinement strengthening whereas particle dispersion strengthening has minor effects. In this study, the recycled AA6061 chip shows the good potential in strengthening as the comparison of using only 17.5% of suggested pressure (70.0/400.0) MPa, the UTS exhibit 35.8% (117.58/327.69) MPa. This shows a remarkable potential of direct recycling by using hot press forging process.

Microstructure and Mechanical Properties of Molybdenum Alloys Doped with ZrB2 Particles

2010 ◽  
Vol 160-162 ◽  
pp. 1828-1833 ◽  
Author(s):  
Guo Jun Zhang ◽  
Jun Zhuo ◽  
Shu Ai Ren
Keyword(s):  
Mechanical Properties ◽  
Mass Fraction ◽  
Zirconium Diboride ◽  
Particle Dispersion ◽  
Dispersion Strengthening ◽  
Pure Molybdenum ◽  
Grain Sizes ◽  
Fine Grain ◽  
Fine Grain Strengthening ◽  
Molybdenum Alloys

The molybdenum alloys doped with various mass fraction zirconium diboride (ZrB2) particles were successfully prepared by using the powder metallurgy technology. The microstructure, hardness and the tensile properties of the pure molybdenum and molybdenum alloys doped with ZrB2 particles were determined at room temperature. Results showed that the addition of zirconium diboride refined the molybdenum grains obviously, meanwhile, molybdenum grain sizes decrease with the increasing of zirconium diboride mass fraction. Measurements on mechanical properties showed that molybdenum alloys doped with ZrB2 particles had higher hardness and strength than pure molybdenum. The analysis and discussion results show that the strengthening mechanisms of ZrB2-doped molybdenum alloys may be attributed to the fine-grain strengthening, particle dispersion strengthening, interfacial-bond strengthening and oxygen reduction strengthening.

scholarly journals Plastic deformation and dissolution of ε-Cu particles by cold rolling in an over-aged particle dispersion strengthening Fe-2mass%Cu alloy

2016 ◽  
Vol 113 ◽  
pp. 48-55 ◽  
Author(s):  
Toshihiro Tsuchiyama ◽  
Shinji Yamamoto ◽  
Satoshi Hata ◽  
Mitsuhiro Murayama ◽  
Satoshi Morooka ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Cold Rolling ◽  
Particle Dispersion ◽  
Dispersion Strengthening ◽  
Cu Alloy

Mechanical Properties of Ultra Fine Particle Dispersion Strengthened Ferritic Steel

2012 ◽  
Vol 706-709 ◽  
pp. 2096-2100 ◽  
Author(s):  
Yoshimasa Funakawa
Keyword(s):  
Mechanical Properties ◽  
Ferritic Steel ◽  
Uniform Elongation ◽  
Low Carbon Steel ◽  
Particle Dispersion ◽  
Low Carbon ◽  
Dispersion Strengthening ◽  
The Matrix ◽  
Ultra Fine Particle ◽  
Hot Rolled

The influence of carbides diameter on the mechanical properties of the ferritic steel that was strengthened by the interface precipitated carbides in rows was investigated. Low carbon steel containing titanium as much as carbon in atomic concentration was induction-melt and hot-rolled, followed by the soaking at some temperatures to obtain completely transformed ferrite in which fine carbides precipitated. Lowering holding temperature resulted in fine carbide generation and reduction of the row spacing. Yield strength significantly increased with the decrease in the carbide diameter. The amount of the particle dispersion strengthening was close to the calculation result according to Ashby-Orowan Mechanism. On the other hand, elongation slowly decreased. The decrease in elongation is caused by the reduction of the uniform-elongation. Local elongation did not change by the change of the diameter of the fine carbides in the matrix since voids in the specimen were generated not besides fine carbides but beside large TiN during tensile test.

Effect of Improved ThO2 Particle Dispersion in Nickel on High-Temperature Strength

1970 ◽  
Vol 28 ◽  
pp. 444-445
Author(s):  
E. R. Kimmel ◽  
H. L. Anthony ◽  
W. Scheithauer
Keyword(s):  
High Temperature ◽  
Metal Matrix ◽  
Oxide Particle ◽  
Oxide Phase ◽  
Dislocation Motion ◽  
Particle Dispersion ◽  
High Temperature Strength ◽  
Strengthening Effect ◽  
Oxide Particles ◽  
The Stability

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.

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.

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