Bulk Nanostructured Al-Based Alloys Produced by High-Pressure Hot Compaction

2005 ◽  
pp. 269-272
Author(s):  
H. Dimitrov ◽  
Jerzy Latuch ◽  
Tadeusz Kulik ◽  
P. Kubecka ◽  
P. Svec
Keyword(s):  
High Pressure ◽  
Hot Compaction

Influence of High Pressure Hot Compaction on Microstructure of Al-Si-Ni-Mm Alloys

2006 ◽  
Vol 114 ◽  
pp. 251-256
Author(s):  
Grzegorz Cieślak ◽  
Jerzy Latuch ◽  
Tadeusz Kulik
Keyword(s):  
High Pressure ◽  
Tensile Strength ◽  
Wear Resistance ◽  
Rare Earth ◽  
Earth Metal ◽  
Late Transition Metal ◽  
High Tensile Strength ◽  
Hot Compaction ◽  
Late Transition ◽  
Bulk Nanocrystalline

Nanocrystalline Al-Si-Ni-Mm alloys have been intensively investigated in recent years. Nanocrystalline Al - based alloys containing silicon (Si), rare earth metal (RE) and late transition metal (Ni), have high tensile strength and good wear resistance. The aim of the work was to manufacture bulk nanocrystalline Al-Si-Ni-Mm system alloys and determine the influence of hot compaction at high pressure on the microstructure. The bulk nanostructured Al73Si19Ni7Mm1 and Al72Si19Ni7Mm2 alloys were produced by high pressure hot compaction of ball milled nanocrystalline ribbons.

High-performance α-Fe/Pr2Fe14B-type nanocomposite magnets produced by hot compaction under high pressure

2000 ◽  
Vol 88 (1) ◽  
pp. 591-593 ◽  
Author(s):  
Zuocheng Wang ◽  
Shouzeng Zhou ◽  
Maocai Zhang ◽  
Yi Qiao
Keyword(s):  
High Pressure ◽  
High Performance ◽  
Nanocomposite Magnets ◽  
Hot Compaction

Consolidation of High Performance AA6061 and AA6061-SiCp Composite Processed by High Pressure Torsion

2014 ◽  
Vol 783-786 ◽  
pp. 2623-2628 ◽  
Author(s):  
W.H. El-Garaihy ◽  
El Sayed M.A. Rassoul ◽  
Hanadi G. Salem
Keyword(s):  
Grain Size ◽  
High Pressure ◽  
Electron Microscope ◽  
High Performance ◽  
High Pressure Torsion ◽  
Structural Evolution ◽  
Triple Junctions ◽  
Hot Compaction ◽  
Before And After ◽  
Scanning Electron

Discs of monolithic AA6061 and AA6061 reinforced with SiCp were processed via combination of hot compaction of the mixed powders followed by high pressure torsion (HPT). HPT processing was investigated using incremental revolutions up to four, under pressures of 1 and 3 GPa. Structural evolution of the powders before and after HPT processing was investigated using scanning electron microscope (SEM). HPT processing of AA6061 discs produced a trimodel structure with micron-scale grains, subgrains and nanoscale substructure of 29, 1.9 μm, and 250 nm, respectively. Reinforcement with SiCp resulted in a refined structure with micron-scale grains, subgrains and nanoscale substructure of 25, 1.9 μm, and 184 nm respectively. The presence of SiCp at the triple junctions and along the grain boundaries enhanced the rate of strain hardening of the Al-matrices and significantly refined the grain size. More pronounced refinements of the grains, subgrains, and substructures were observed with increasing the HPT pressure up to 3 GPa.

Bulk Nanostructured Al-Based Alloys Produced by High-Pressure Hot Compaction

2005 ◽  
Vol 101-102 ◽  
pp. 269-272
Author(s):  
H. Dimitrov ◽  
Jerzy Latuch ◽  
Tadeusz Kulik ◽  
P. Kubecka ◽  
P. Svec
Keyword(s):  
High Pressure ◽  
Hot Compaction

Bulk Nanostructured Al-Si-Ni-Mishmetal Alloys Produced by High-Pressure Hot Compaction

2007 ◽  
Vol 130 ◽  
pp. 189-192 ◽  
Author(s):  
Grzegorz Cieślak ◽  
Jerzy Latuch ◽  
Tadeusz Kulik
Keyword(s):  
High Pressure ◽  
Melt Spinning ◽  
Earth Metal ◽  
High Strength ◽  
Al Alloy ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Hot Compaction ◽  
Late Transition ◽  
Bulk Nanocrystalline

Nanocrystalline Al-based alloys containing silicon (Si), rare earth metal (RE) and late transition metal (Ni), combine high tensile strength and good wear resistance. The aim of this work was to manufacture high strength bulk nanocrystalline alloys from Al-Si-Ni-Mm system. Bulk nanostructured alloys were produced by ball-milling of nanocrystalline ribbons followed by high-pressure (7.7 GPa) hot compaction (320°C). Nanocrystalline ribbons of investigated alloys were produced by melt-spinning technique. The crystallization process was studied using differential scanning calorimeter. The phase compositions of the ribbons were characterized by X-ray diffraction, scanning and transmission electron microscopy. Vickers hardness of nanostructured compacted samples, measured with the load of 1 kG, achieved values five times higher than that of commercial 4xxx series Al alloy.

High-pressure freezing of cells in suspension for low-voltage scanning electron microscopy (LVSEM)

1991 ◽  
Vol 49 ◽  
pp. 64-65
Author(s):  
Marek Malecki ◽  
James Pawley ◽  
Hans Ris
Keyword(s):  
Electron Microscopy ◽  
High Pressure ◽  
Low Voltage ◽  
Culture Media ◽  
Cell Structure ◽  
Freeze Substitution ◽  
Ice Crystal ◽  
High Pressure Freezing ◽  
Cell Culture Media ◽  
Voltage Scanning

The ultrastructure of cells suspended in physiological fluids or cell culture media can only be studied if the living processes are stopped while the cells remain in suspension. Attachment of living cells to carrier surfaces to facilitate further processing for electron microscopy produces a rapid reorganization of cell structure eradicating most traces of the structures present when the cells were in suspension. The structure of cells in suspension can be immobilized by either chemical fixation or, much faster, by rapid freezing (cryo-immobilization). The fixation speed is particularly important in studies of cell surface reorganization over time. High pressure freezing provides conditions where specimens up to 500μm thick can be frozen in milliseconds without ice crystal damage. This volume is sufficient for cells to remain in suspension until frozen. However, special procedures are needed to assure that the unattached cells are not lost during subsequent processing for LVSEM or HVEM using freeze-substitution or freeze drying. We recently developed such a procedure.

Prolonged Fixation Studies For Spaceflight

1973 ◽  
Vol 31 ◽  
pp. 332-333
Author(s):  
Robert Corbett ◽  
Delbert E. Philpott ◽  
Sam Black
Keyword(s):  
High Pressure ◽  
Living Systems ◽  
Prolonged Storage ◽  
Time Intervals ◽  
Early Signs ◽  
Large Numbers

Observation of subtle or early signs of change in spaceflight induced alterations on living systems require precise methods of sampling. In-flight analysis would be preferable but constraints of time, equipment, personnel and cost dictate the necessity for prolonged storage before retrieval. Because of this, various tissues have been stored in fixatives and combinations of fixatives and observed at various time intervals. High pressure and the effect of buffer alone have also been tried.Of the various tissues embedded, muscle, cartilage and liver, liver has been the most extensively studied because it contains large numbers of organelles common to all tissues (Fig. 1).

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