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 Production and Thermal Stability of a Refined Dispersion of Er2O3 in Ti3Al using Rapid Solidification Processing

1984 ◽  
Vol 39 ◽  
Author(s):  
D. G. Konitzer ◽  
H. L. Fraser
Keyword(s):  
Heat Treatment ◽  
Thermal Stability ◽  
Solid Solution ◽  
Rapid Solidification ◽  
Elevated Temperatures ◽  
Rapid Solidification Processing ◽  
Laser Surface ◽  
Second Phase ◽  
Solidification Processing ◽  
Thermal Stability Of

ABSTRACTThe use of rapid solidification processing to produce a refined dispersion of second phase in Ti3Al is demonstrated. Laser surface melting produces a disordered solid solution of Ti and Al with a supersaturation of Er and 0. A refined dispersion of Er2O3 is formed on heat treatment at 973 K. This oxide is found to be stable at elevated temperatures up to 1173 K.

Grain-Coarsening Resistance and The Stability of Second-Phase Dispersions in Rapidly Solidified Steels

1981 ◽  
Vol 8 ◽  
Author(s):  
G. B. Olson ◽  
H. C. Ling ◽  
J. S. Montgomery ◽  
J. B. Vander Sande ◽  
M. Cohen
Keyword(s):  
Rare Earth ◽  
Grain Boundary ◽  
Alloy Composition ◽  
Second Phase ◽  
Alloy Development ◽  
Grain Coarsening ◽  
Dispersed Phases ◽  
Grain Boundary Pinning ◽  
The Stability ◽  
Rapidly Solidified

ABSTRACTControl of alloy composition and processing to achieve grain coarsening resistance in rapidly solidified alloys is examined via the theory of grain boundary pinning and particle coarsening. The principles are illustrated for the case of manganese sulfides in steels. A thermodynamic survey of potential stable dispersed phases identifies TiN and rare-earth sulfides as particularly promising for alloy development via rapid solidification.

Rapidly Solidified Ti Alloys Containing Metalloids and Rare Earth Metals— Their Microstructure and Mechanical Properties

1983 ◽  
Vol 28 ◽  
Author(s):  
C.S. Chi ◽  
S.H. Whang
Keyword(s):  
Rare Earth ◽  
Melt Spinning ◽  
Elevated Temperatures ◽  
Age Hardening ◽  
Second Phase ◽  
Precipitation Reaction ◽  
Strength Increase ◽  
Ti Alloys ◽  
Significant Difference ◽  
Rapidly Solidified

ABSTRACTRapidly solidified (RS) Ti alloys containing novel additives were prepared by splat quenching and melt spinning techniques. Microstructures of the as-quenched and heat-treated alloys were studied by electron microscopies. The results show that microstructural refinement and precipitation reaction are universal phenomena in all RS Ti alloys. A significant difference in second phase coarsening was observed between metalloid-origin precipitates and those of rare earth-origin. The precipitates in a Ti-Al-La(Ce) were identified predominantly as rare earth-Al compounds. Exce llent stability for rare earth-origin precipitates was found.Except for a carbon-containing alloy (700 ° C), age hardening behavior is a universal phenomenon in all RS Ti alloys with additives. A significant strength increase (hardness) in the RS alloy was noted at both room and elevated temperatures.

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.

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.

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).

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.

Au0.80Cu0.10Y0.10, A Gold-Rich Ternary Alloy Glass with Tc > 400°C and its Crystallization Kinetics

1993 ◽  
Vol 321 ◽  
Author(s):  
Sunil V. Gokhale ◽  
Krassimir G. Marchev ◽  
Welville B. Nowak ◽  
Bill C. Giessen
Keyword(s):  
Activation Energy ◽  
Rare Earth ◽  
Room Temperature ◽  
Glassy State ◽  
Rapid Solidification Processing ◽  
Arc Furnace ◽  
Solidification Processing ◽  
Glass Forming ◽  
New Family ◽  
Activation Energy Of Crystallization

ABSTRACTThere are no reported gold-rich alloys that are both readily glass forming (RGF) upon rapid solidification processing (RSP) and, in the glassy state, have crystallization temperatures Tc sufficiently high to insure long metastable life times at room temperature. A representative of a new family of ternary gold-based glasses is described that contain Cu and a rare earth (RE) Metal (or Y), with total addition element concentrations as low as 15 at. pet., and its crystallization characteristics are reported. Under RSP processing by arc furnace hammer-and-anvil quenching, the alloy Au0.80Cu0.10Y0.10 readily forms a ductile glass, with Tc = 685 K, ΔHc = 1.25 kJ/g-Mole and an activation energy of crystallization ΔE3 (cryst.) = 190 kJ/g-Mole.

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