Rapidly Solidified Long Range Ordered Alloys

1981 ◽  
Vol 8 ◽  
Author(s):  
E. H. Lee ◽  
C. C. Koch ◽  
C. T. Liu
Keyword(s):  
Long Range ◽  
Cell Structure ◽  
Rapid Solidification Processing ◽  
Microstructural Feature ◽  
Solidification Processing ◽  
Transmission Electron ◽  
Ordered Alloys ◽  
Before And After ◽  
Rapidly Solidified ◽  
Carbide Particles

ABSTRACTThe influence of rapid solidification processing on the microstructure of long-range-ordered alloys in the (Fe,Co,Ni)3 V system has been studied by transmission electron microscopy. The main microstructural feature of the asquenched alloys was a fine cell structure (∼300 nm diameter) decorated with carbide particles. This structure was maintained after annealing treatments which develop the ordered crystal structure. Other features of the microstructures both before and after annealing are presented and discussed.

The structure of rapidly solidified Fe-Ni-Mo-Co-B ribbons

1989 ◽  
Vol 47 ◽  
pp. 290-291
Author(s):  
D. M. Vanderwalker
Keyword(s):  
Electron Microscopy ◽  
Cell Walls ◽  
Lattice Parameter ◽  
Rapid Solidification Processing ◽  
Solidification Processing ◽  
Casting Technique ◽  
Transmission Electron ◽  
Structural Applications ◽  
Melt Spun ◽  
Rapidly Solidified

Fundamental aspects of solidification can be examined by experimentation in rapid solidification processing. The structure produced depends on parameters such as cooling rate, degree of undercooling, heat flow, and growth rate. Rapidly solidified iron base alloys are being developed for structural applications.RSR I Fe-19.7Mo-14.4Ni-7.3Co-1.9Bwt % and RSR II Fe-15.0Ni-11.1Mo-7.4Co-0.84B wt% ribbons were melt spun by a jet casting technique. RSR I ribbons were annealed for one hour at 816°C.Specimens were prepared for transmission electron microscopy by punching 3 mm discs from ribbons and electropolishing in a methanol 5% perchloric acid solution.The TEM was performed on the JEM 200CX electron microscope.As solidified RSR I was found to be canposed of fine (7nm) polycrystalline α-Fe. There is evidence for the presence of Ni Mo and FeB (Fig.1). On annealing, the α-Fe transforms to γ-Fe and FeB2Mo2, with significant grain growth (Fig.2). The as-solidified RSR II contains cellular γ-Fe with fcc-Fe2 3B6 of lattice parameter a=l.067nm at the cell walls (Fig. 3).

Segregation and domain structure in rapidly solidified Ni3Al

1983 ◽  
Vol 41 ◽  
pp. 248-249
Author(s):  
J. A. Horton ◽  
C. C. Koch ◽  
C. T. Liu
Keyword(s):  
Solidification Rate ◽  
Domain Size ◽  
Microstructural Characterization ◽  
Rapid Solidification Processing ◽  
Solidification Processing ◽  
Antiphase Boundaries ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Rapidly Solidified ◽  
Average Domain

Rapid solidification processing (RSP) in conjunction with microalloying is being used to enhance the ductility of Ni3Al. Boron which strengthens grain boundaries was added for significant improvement in ductility of Ni3Al. Specimens of Ni3Al (24 at. % Al) with additions of 0, 500, and 1000 wt ppm boron were splat-cooled in an arc-hammer apparatus. The specimens without boron were brittle while specimens with boron were ductile for all but the fastest quench rates. Microstructural characterization was performed with a Philips EM400T/FEG and JEM 120CX transmission electron microscopes.Antiphase boundaries (APB) are not observed in Ni3A1 alloys fabricated from cast ingots, but are present following RSP. The average domain sizes were 50 and 80 nm for specimens with and without boron, respectively, but were independent of solidification rate. Near the surface of the splats the domain size was approximately the same as in the center even though the grain size was much smaller. Regions of small domains which were always in the center of the grains were surrounded by larger domains.

Microstructural Morphology and Phase Structure of Rapidly Solidified Hypereutectic Al-Si Alloys

2009 ◽  
Vol 79-82 ◽  
pp. 139-142
Author(s):  
Ai Qin Wang ◽  
Ji Wen Li ◽  
Jing Pei Xie ◽  
Wen Yan Wang
Keyword(s):  
Melt Spinning ◽  
Primary Silicon ◽  
Nucleation And Growth ◽  
Rapid Solidification Processing ◽  
Solidification Processing ◽  
Α Phase ◽  
Equilibrium Solidification ◽  
Microstructural Morphology ◽  
Rapidly Solidified ◽  
Morphology Characteristics

In the present work, rapidly solidified hypereutectic Al-Si-Cu-Mg alloys strips was prepared by single roller melt-spinning method. The microstructures, phase and morphology characteristics of the resultant strips were characterized by means of SEM, TEM and XRD technique. The results show that the grains are refined after rapid solidification processing, and the micro-nanocrystals are formed. Compared with equilibrium solidification, the microstructures are changed obviously. The nucleation and growth of primary silicon are suppressed and primary silicon can not deposited, meanwhile, α-Al phase is nucleated which prior to eutectic. Therefore, the microstructures become into the metastable state. The microstructures of the strips are composed of primary micro-nanostructure α phase and feather-needles-like (α+Si) eutectic which set in the α phase. The mechanism of the formation for microstructures of melt-spinning Al–Si alloy have also been discussed.

Rapid Solidification of an Aluminum-Neodymium Alloy

1983 ◽  
Vol 28 ◽  
Author(s):  
S. J. Savage ◽  
F. H. Froes
Keyword(s):  
Heat Treatment ◽  
Rapid Solidification ◽  
Heat Treatments ◽  
Rapid Solidification Processing ◽  
Solidification Processing ◽  
Preliminary Results ◽  
Different Response ◽  
Rapidly Solidified ◽  
Microstructural Studies

ABSTRACTA rationale for rapid solidification processing of aluminum-lanthanide alloys is given, and preliminary results of microstructural studies on an aluminum-neodymium alloy are presented. Three distinct types of microstructure are seen in the as-cast rapidly solidified material, which are still evident after heat treatment at 350°C for 1 hour. Microhardness measurements indicate each microstructure has a different response to isochronal heat treatments.

Changes of electrical impedance characteristics with the radiation induced damage on biological tissue constituents

2021 ◽  
pp. 1-13
Author(s):  
Sang Hyeong Kil ◽  
Gyeong Rip Kim ◽  
Moo Seok Lee ◽  
Jong Hyeok Kwak ◽  
Yeong Hyeon Lim ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Irradiation Dose ◽  
Electrical Impedance ◽  
Cell Structure ◽  
Tissue Samples ◽  
Transmission Electron ◽  
Impedance Characteristics ◽  
Before And After ◽  
Radiation Induced ◽  
Mean Differences

This study analyzes the response of increasing radiation dose to the pork tenderloin tissue. Considering its significant cell structure, pork tenderloin tissue samples are selected for the experimental objects to measure their electrical impedance characteristics. This study proposes and investigates an effective approach to characterize the variation of the internal change of the components of pork tenderloin tissues caused by radiation. Changes in the pork tenderloin tissues are that the gap of the myotome is more far apart with increase of radiation dose because of the destroyed Myofibrils under the damage. With the increase of radiation dose, the impedance value of the pork tenderloin tissue decreases. Each of mean differences in the impedance values before and after irradiation dose under 1 Gy, 2 Gy and 4 Gy show 0.55±0.03, 1.09±0.14 and 1.97±0.14, respectively. However, the mean difference substantially increases to 13.08±0.16 at irradiation dose of 10 Gy. Thus, the cell membrane shows the most severe rupture at a radiation dose of 10 Gy. Changes in the microstructure of the irradiated pork tenderloin tissue samples are also checked and validated by a transmission electron microscope.

Oxide Dispersions in Rapidly Solidified Ti Alloys

1983 ◽  
Vol 28 ◽  
Author(s):  
D.G. Konitzer ◽  
R. Kirchheim ◽  
H.L. Fraser
Keyword(s):  
Heat Treatment ◽  
Rare Earth ◽  
Rare Earth Oxide ◽  
Rapid Solidification Processing ◽  
Laser Surface ◽  
Second Phase ◽  
Solidification Processing ◽  
Ti Alloys ◽  
The Stability ◽  
Rapidly Solidified

ABSTRACTTechniques of rapid solidification processing were used to refine a dispersion of rare earth oxides in Ti. The dispersion was produced by laser surface melting and subsequent heat treatment of a Ti-Er alloy. The second phase was identified as the rare earth oxide. The stability of the dispersion was investigated analytically and experimentally and the correlation between the analysis and experiments was shown to be very good.

The Effect of Cu-Macroalloying Additions to Rapidly Solidified NiAl Intermetallic Compound

2000 ◽  
Vol 646 ◽  
Author(s):  
J. Colin ◽  
B. Campillo ◽  
C. Gonzalez ◽  
O. Alvarez-Fregoso ◽  
J. A. Juarez-Islas
Keyword(s):  
Intermetallic Compound ◽  
Room Temperature ◽  
Alloy Composition ◽  
Argon Atmosphere ◽  
Solidification Processing ◽  
Electron Microscopic ◽  
Room Temperature Ductility ◽  
Transmission Electron ◽  
Transmission Electron Microscopic ◽  
Rapidly Solidified

ABSTRACTThe effects of two variables on the NiAl intermetallic compound were studied: 1) copper macroalloying additions and 2) rapid solidification processing. For that purpose, several NiCuAl alloys were vacuum induction melted and rapidly solidified by using a copper wheel, rotating at 15 m/s, under an argon atmosphere. Chemical analysis of as-rapidly solidified ribbons indicated, that four alloy compositions lie in the β-(Ni, Cu)Al field, one alloy composition lie in the boundary of the β-(Ni, Cu)Al/(Ni, Cu)2Al3 fields, one alloy composition lies in the boundary of the β-(Ni, Cu)Al/β-(Ni, Cu)Al + (Ni, Cu)3Al fields and two alloy compositions lie in the β-(Ni, Cu)Al + (Ni, Cu)3Al field. Transmission electron microscopic observations carried out in as-rapidly solidified ribbons, revealed the presence of at least three main structures: i) β-(Ni, Cu)Al, ii) β-(Ni, Cu)Al + martensite (Ni, Cu)Al and iii) (Ni, Cu)3Al + martensite (Ni, Cu)Al. Microhardness Vickers and tensile test data indicated that alloys with a β-(Ni, Cu)Al + martensite (Ni, Cu)Al microstructure have improved room temperature ductility, reaching values of elongation up to 3.28 %.

Effect of Rapid Solidification Processing on Hydrogen Behaviour in Aluminium

2010 ◽  
Vol 654-656 ◽  
pp. 998-1001 ◽  
Author(s):  
Iya I. Tashlykova-Bushkevich ◽  
Takahiro Shikagawa ◽  
Vasiliy G. Shepelevich ◽  
Goroh Itoh
Keyword(s):  
Atomic Force Microscopy ◽  
Rapid Solidification ◽  
Thermal Desorption Spectroscopy ◽  
Rapid Solidification Processing ◽  
Alloying Element ◽  
Solidification Processing ◽  
Force Microscopy ◽  
Atomic Force ◽  
Afm Analysis ◽  
Rapidly Solidified

Thermal desorption spectroscopy (TDS) technique has been used to study hydrogen behaviour in rapidly solidified (RS) aluminium (Al) both as-cast and exposed to humid air (HA). The surface morphology of the foils was studied through atomic force microscopy (AFM). Analysis was made of the effect of rapid solidification processing (RSP) on H/microstructure interactions, including investigation of alloying element (0.05 at % Ti) influence on H trapping in Al.

scholarly journals Transmission Electron Microscopy of RSP Fe/Cr/Mn/Mo/C Alloy

1981 ◽  
Vol 8 ◽  
Author(s):  
J. J. Rayment ◽  
G. Thomas
Keyword(s):  
Electron Beam ◽  
Electron Beam Melting ◽  
Sliding Wear ◽  
Wear Behavior ◽  
Rapid Solidification Processing ◽  
Duplex Microstructure ◽  
Solidification Processing ◽  
Transmission Electron ◽  
Martensitic Microstructure ◽  
Ferrite Grain Size

ABSTRACTRapid solidification processing (RSP) has been carried out on an Fe/Cr/Mn/Mo/C alloy using both electron-beam melting and piston-and-anvil techniques. Preliminary TEM results show RSP produces a refined duplex microstructure of ferrite and martensite, with a typical ferrite grain size of 0.50–3.0 microns. This RSP microstructure is significantly different from that observed in the conventionally austenitized and quenched alloys—a lath martensitic microstructure with thin films of retained interlath austenite. The morphological change produced by RSP is accompanied by an increase in hardness from 48Rc to 61Rc (^ 480 to 720 VHN). It is intended to use electron-beam specimens to examine the potential beneficial effect of RSP upon sliding wear resistance and, by careful TEM studies, it will be possible to characterize the microstructure and its role in the hardness and wear behavior of the RSP alloy.

Effect of Rapid Solidification on Microstructural Features of Al-Cr Alloys

2012 ◽  
Vol 706-709 ◽  
pp. 301-304 ◽  
Author(s):  
Iya I. Tashlykova-Bushkevich ◽  
Goroh Itoh
Keyword(s):  
Surface Topography ◽  
Rapid Solidification ◽  
Surface Composition ◽  
Hydrogen Desorption ◽  
Rapid Solidification Processing ◽  
Hydrogen Trapping ◽  
Alloying Element ◽  
Solidification Processing ◽  
Near Surface ◽  
Rapidly Solidified

Microstructure of rapidly solidified (RS) pure Al and Al-0.8; 1.0 Cr alloys (at %) foils was examined with reference to near surface composition, solute/microstructure interactions, and surface topography. The hydrogen desorption from Al-Cr alloys was investigated in order to clarify effect of rapid solidification processing (RSP) on hydrogen trapping in specimens. It is suggested that hydrogen occupancy for vacancy traps in the alloys is decreased in contrast to that reported for pure Al foils and is related to the formation of vacancy-alloying element atom complexes.

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