Solid-state recycling for machined chips of iron by hot extrusion and annealing

2004 ◽  
Vol 19 (5) ◽  
pp. 1524-1530 ◽  
Author(s):  
Yasumasa Chino ◽  
Hajime Iwasaki ◽  
Mamoru Mabuchi
Keyword(s):  
Solid State ◽  
Dislocation Density ◽  
Yield Stress ◽  
Grain Refinement ◽  
Pure Iron ◽  
Room Temperature ◽  
Hot Extrusion ◽  
Low Energy ◽  
High Dislocation Density ◽  
High Ductility

Solid-state recycling for machined chips of pure iron by hot extrusion at 823 K and annealing at 1073–1273 K was carried out. The as-extruded solid recycled specimen without annealing was fractured prior to yielding at room temperature. However, high ductility was recovered by annealing at 1073–1273 K. This is because the oxides at the interface of the machined chips dispersed in grain by annealing. The annealed solid recycled specimens showed higher yield stress than the annealed virgin extruded specimens. Grain refinement for the solid recycled specimens was enhanced by the high dislocation density in the machined chips, resulting in higher strength in the recycled specimens. Thus, the solid-state recycling is a low energy upgrade recycle process.

Microstructure and Mechanical Properties of Mechanically Alloyed NiAl

1990 ◽  
Vol 213 ◽  
Author(s):  
S. J. Hwang ◽  
P. Nash ◽  
M. Dollar ◽  
S. Dymek
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Dislocation Density ◽  
Work Hardening ◽  
Room Temperature ◽  
Hot Extrusion ◽  
Homogeneous Distribution ◽  
Mechanically Alloyed ◽  
Oxide Particles ◽  
Temperature Work

ABSTRACTMechanical alloying (MA) has been used to produce NiAl powders from either elemental or prealloyed constituents. The powders were consolidated by hot extrusion resulting in material which was fully dense, with a grain size around 1 μm and a homogeneous distribution of oxide particles with sizes in the range 10 to 100 nm. TEM observation indicates the presence of a significant dislocation density after consolidation. Mechanical properties have been studied by compression testing from room temperature to 1300 K in air. Yield strengths ranged from 1453 MPa to 32 MPa depending on material and test temperature. Work hardening was observed at all test temperatures for both materials. Substantial ductility was observed even at room temperature where it exceeds 7.5 %. The effects of microstructure on the mechanical properties are discussed.

Research on Superplastic Zn-22Al Alloy with a Large Size to a New Seismic Damper

2011 ◽  
Vol 250-253 ◽  
pp. 773-776
Author(s):  
Ling Jun Kong ◽  
Xue Hua Dong ◽  
Yan Bei Chen ◽  
Xiang Liang Ning ◽  
Jing Tao Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Yield Stress ◽  
Work Hardening ◽  
Room Temperature ◽  
High Ductility ◽  
Seismic Damper ◽  
Large Size

To develop a superplastic damping device, the mechanical properties and superplastic capability of Zn-22Al alloy with a large size in the rolled samples were investigated. It is indicated that the alloy with a large size has some advantage properties, such as high ductility, low yield stress and low work hardening at room temperature, which is very useful to a seismic damper.

scholarly journals Effect of Rolling Speed on Microstructural and Microtextural Evolution of Nb Tubes during Caliber-Rolling Process

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 500 ◽  
Author(s):  
Jongbeom Lee ◽  
Haguk Jeong
Keyword(s):  
Grain Size ◽  
Dislocation Density ◽  
Ambient Temperature ◽  
Strain Rate ◽  
Internal Energy ◽  
Grain Refinement ◽  
Rolling Process ◽  
Fiber Texture ◽  
Rolling Speed ◽  
Low Energy

This study investigated the fabrication of Nb tubes via the caliber-rolling process at various rolling speeds from 1.4 m/min to 9.9 m/min at ambient temperature, and the effect of the caliber-rolling speed on the microstructural and microtextural evolution of the Nb tubes. The caliber-rolling process affected the grain refinement when the Nb tube had a higher fraction of low angle grain boundaries. However, the grain size was identical regardless of the rolling speed. The dislocation density of the Nb tubes increased with the caliber-rolling speed according to the Orowan equation. The reduction of intensity for the <111> fiber texture and the development of the <112> fiber texture with the increase of the strain rate are considered to have decreased the internal energy by increasing the fraction of the low-energy Σ3 boundaries.

Deformation Behavior of Ultrafine Grained Iron

2006 ◽  
Vol 503-504 ◽  
pp. 317-322 ◽  
Author(s):  
Setsuo Takaki ◽  
Kenji Kawasaki ◽  
Y. Futamura ◽  
Toshihiro Tsuchiyama
Keyword(s):  
Grain Size ◽  
Dislocation Density ◽  
Yield Stress ◽  
Grain Refinement ◽  
Work Hardening ◽  
Coarse Grained ◽  
Deformation Condition ◽  
Initial Yield Stress ◽  
Ultrafine Grained ◽  
Dislocation Strengthening

Work hardening behavior and microstructure development during deformation by cold rolling were investigated in iron with different grain size. Grain refinement makes the introduction of dislocation easier. For instance, under the same deformation condition (5% reduction in thickness), dislocation density is the order of 1014m-2 in a coarse grained material (mean grain size; 20μm), while it reaches 7×1015m-2 in an ultrafine grained material (0.25μm). It is well known that the yield stress of metals is enlarged with an increase in dislocation density on the basis of the Bailey-Hirsch relationship. However, it should be noted that the ultrafine grained material never undergoes usual work hardening although the dislocation density is surely enhanced to around the order of 1016m-2: 0.2% proof stress is almost constant at 1.4 ~ 1.5GPa regardless of the amount of deformation. The dislocation density of 1016m-2 is thought to be the limit value which can be achieved by cold working of iron and the yield stress of iron with this dislocation density (ρ) is estimated at 1.1GPa from the Bailey-Hirsch relationship; σd [Pa] = 0.1×109 + 10 ρ1/2. On the other hand, yield stress of iron is enhanced by grain refinement on the basis of the Hall-Petch relationship; σgb [Pa] = 0.1×109 + 0.6×109 d-1/2 as to the grain size d [μm]. This equation indicates that the grain size of 0.35 μm gives the same yield stress as that estimated for the limit of dislocation strengthening (1.1GPa). As a result, it was concluded that work hardening can not take place in ultrafine grained iron with the grain size less than 0.35 μm because dislocation strengthening can not exceed the initial yield stress obtained by grain refinement strengthening.

scholarly journals SURFACE MORPHOLOGY AND SPUTTERING OF FeCrAl COATING ON STEEL EXPOSED TO LOW-ENERGY DEUTERIUM PLASMAS

2019 ◽  
pp. 190-194
Author(s):  
V.N. Voyevodin ◽  
G.D. Tolstolutskaya ◽  
A.V. Nikitin ◽  
R.L. Vasilenko ◽  
A.S. Kuprin ◽  
...  
Keyword(s):  
Pure Iron ◽  
Room Temperature ◽  
Nitrogen Atmosphere ◽  
Low Energy ◽  
Vacuum Arc ◽  
Published Data ◽  
Deuterium Plasma ◽  
X Ray ◽  
Order Of Magnitude ◽  
Sputtering Yields

Processes of sputtering and surface modification of FeCrAl coatings deposited on steel by vacuum arc was studied under the influence of low-energy (500 eV) deuterium plasma with fluence (4⋅1024) D+/m2 at room temperature. It was determined the composition of coatings by an energy dispersive X-ray spectrometer allowed to establish that the elements in the coatings are distributed more evenly when it coated in a nitrogen atmosphere. Results of erosion studies indicated that the sputtering yields for deuterium on coatings are 1.3…0.45 at./ion and at least two-three times less in comparison with initial alloys and published data for pure iron and chromium. For coatings deposited in a nitrogen atmosphere found that the obtained sputtering coefficients are almost an order of magnitude smaller in comparison with published data for pure iron and chromium and only 1.8 times higher compared to tungsten.

Stability of Ultrafine-Grained Microstructure in Fcc Metals Processed by Severe Plastic Deformation

2011 ◽  
Vol 465 ◽  
pp. 195-198 ◽  
Author(s):  
Jenő Gubicza ◽  
Nguyen Q. Chinh ◽  
Sergey V. Dobatkin ◽  
E. Khosravi ◽  
Terence G. Langdon
Keyword(s):  
Thermal Stability ◽  
Plastic Deformation ◽  
Dislocation Density ◽  
Severe Plastic Deformation ◽  
Room Temperature ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
High Dislocation Density ◽  
Ultrafine Grained ◽  
The Stability

The thermal stability of ultrafine-grained (UFG) microstructure in face centered cubic metals processed by severe plastic deformation (SPD) was studied. The influence of the SPD procedure on the stability was investigated for Cu samples processed by Equal-Channel Angular Pressing (ECAP), High-Pressure Torsion (HPT), Multi-Directional Forging and Twist Extrusion at room temperature (RT). It is found that HPT results in the lowest thermal stability due to the very high dislocation density. Furthermore, the effect of the low stacking fault energy of Ag on the stability is also investigated. It is revealed that the UFG microstructure produced in Ag by ECAP is recovered and recrystallized during storage at room temperature. The driving force for this unusual recovery and recrystallization is the high dislocation density developed during ECAP due to the high degree of dislocation dissociation caused by the very low stacking fault energy of Ag.

Ultra-fine-grained Zn-0.5Mn alloy processed by multi-pass hot extrusion: Grain refinement mechanism and room-temperature superplasticity

2019 ◽  
Vol 748 ◽  
pp. 262-266 ◽  
Author(s):  
Pushan Guo ◽  
Fuxia Li ◽  
Lijing Yang ◽  
Robabeh Bagheri ◽  
Qingke Zhang ◽  
...  
Keyword(s):  
Grain Refinement ◽  
Room Temperature ◽  
Hot Extrusion ◽  
Fine Grained ◽  
Refinement Mechanism

Solid-state recycling from machined scraps to a cellular solid

2002 ◽  
Vol 17 (11) ◽  
pp. 2783-2786 ◽  
Author(s):  
Yasumasa Chino ◽  
Koji Shimojima ◽  
Hiroyuki Hosokawa ◽  
Yasuo Yamada ◽  
Cui'e Wen ◽  
...  
Keyword(s):  
Solid State ◽  
Dislocation Density ◽  
Medium Carbon Steel ◽  
High Dislocation Density ◽  
Cellular Solids ◽  
Plateau Region ◽  
Medium Carbon ◽  
Cellular Solid ◽  
The One ◽  
Compressive Tests

Cellular solids were processed from machined scraps of a medium carbon steel by sintering. Mechanical properties of the cellular solids were investigated by compressive tests from the viewpoint of effects of high dislocation density in the machined scraps on the solid-state bonding. The flow stress in the plateau region for the cellular solid made of the as-machined scraps was higher than that of the one made of the annealed scraps. Clearly, the bonding strength between scraps was increased by the high dislocation density in the as-machined scraps.

Observations of dislocation interactions with recrystallized grain boundaries

1988 ◽  
Vol 46 ◽  
pp. 628-629
Author(s):  
C. W. Price
Keyword(s):  
Dislocation Density ◽  
Grain Boundary ◽  
Strain Rate ◽  
Grain Boundaries ◽  
Dislocation Structure ◽  
Hot Deformation ◽  
Static Recrystallization ◽  
High Dislocation Density ◽  
High Angle ◽  
Dislocation Interactions

Little evidence exists on the interaction of individual dislocations with recrystallized grain boundaries, primarily because of the severely overlapping contrast of the high dislocation density usually present during recrystallization. Interesting evidence of such interaction, Fig. 1, was discovered during examination of some old work on the hot deformation of Al-4.64 Cu. The specimen was deformed in a programmable thermomechanical instrument at 527 C and a strain rate of 25 cm/cm/s to a strain of 0.7. Static recrystallization occurred during a post anneal of 23 s also at 527 C. The figure shows evidence of dissociation of a subboundary at an intersection with a recrystallized high-angle grain boundary. At least one set of dislocations appears to be out of contrast in Fig. 1, and a grainboundary precipitate also is visible. Unfortunately, only subgrain sizes were of interest at the time the micrograph was recorded, and no attempt was made to analyze the dislocation structure.

Improved Sol-Gel Materials for Efficient Solid State Dye Lasers

1993 ◽  
Vol 329 ◽  
Author(s):  
Michael Canva ◽  
Patrick Georges ◽  
Jean-Fran^ois Perelgritz ◽  
Alain Brun ◽  
Fréddric Chaput ◽  
...  
Keyword(s):  
Solid State ◽  
Physical Properties ◽  
Room Temperature ◽  
Sol Gel ◽  
Tunable Lasers ◽  
Optical Quality ◽  
Dye Lasers ◽  
Laser Dyes ◽  
Host Matrix ◽  
Host Matrices

AbstractPhotoresistant laser dyes were trapped in silica based xerogel host matrices to obtain solid state tunable lasers. For this purpose very dense xerogel samples with improved chemical and physical properties were prepared at room temperature by the sol-gel technology. The as-prepared materials were polished to obtain optical quality surfaces and were used as new lasing media.Lasing action of such different dyes as rhodamine, perylene and pyrromethene doping dense sol-gel matrices was demonstrated. Efficiencies of 30 % or lifetimes of more than 100,000 shots were achieved with different new ≤dye dopant/host matrix≥ couples. Their different performances are reviewed and discussed.

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