The formation of chondrule-containing extraterrestrial materials: Evidence for rapid solidification under microgravity conditions

1984 ◽  
Vol 67 (1-3) ◽  
pp. 413-419 ◽  
Author(s):  
Phyllis Zych Budka
Keyword(s):  
Rapid Solidification ◽  
Microgravity Conditions ◽  
Extraterrestrial Materials

Lorentz electron microscopy of magnetic domains in rapidly solidified and annealed Pt-Co-B alloys

1991 ◽  
Vol 49 ◽  
pp. 784-785
Author(s):  
N. Qiu ◽  
J. E. Wittig
Keyword(s):  
Rapid Solidification ◽  
Ion Beam ◽  
Magnetic Behavior ◽  
High Coercivity ◽  
Magnetic Domains ◽  
Beam Angle ◽  
Tem Analysis ◽  
Intrinsic Coercivity ◽  
Hard Magnets ◽  
Rapidly Solidified

PtCo hard magnets have specialized applications owing to their relatively high coercivity combined with corrosion resistance and ductility. Increased intrinsic coercivity has been recently obtained by rapid solidification processing of PtCo alloys containing boron. After rapid solidification by double anvil splat quenching and subsequent annealing for 30 minutes at 650°C, an alloy with composition Pt42Co45B13 (at.%) exhibited intrinsic coercivity up to 14kOe. This represents a significant improvement compared to the average coercivities in conventional binary PtCo alloys of 5 to 8 kOe.Rapidly solidified specimens of Pt42Co45B13 (at.%) were annealed at 650°C and 800°C for 30 minutes. The magnetic behavior was characterized by measuring the coercive force (Hc). Samples for TEM analysis were mechanically thinned to 100 μm, dimpled to about 30 nm, and ion milled to electron transparency in a Gatan Duomill at 5 kV and 1 mA gun current. The incident ion beam angle was set at 15° and the samples were liquid nitrogen cooled during milling. These samples were analyzed with a Philips CM20T TEM/STEM operated at 200 kV.

Interfacial structures of dissimilar materials joined by capacitor-discharge welding

1994 ◽  
Vol 52 ◽  
pp. 534-535
Author(s):  
C. P. Doğan ◽  
R. D. Wilson ◽  
J. A. Hawk
Keyword(s):  
Rapid Solidification ◽  
Fusion Zone ◽  
Dissimilar Materials ◽  
Solidification Process ◽  
Weld Interface ◽  
Capacitor Discharge ◽  
Fine Grained ◽  
Iron Aluminum ◽  
Conductive Ceramics ◽  
Capacitor Discharge Welding

Capacitor Discharge Welding is a rapid solidification technique for joining conductive materials that results in a narrow fusion zone and almost no heat affected zone. As a result, the microstructures and properties of the bulk materials are essentially continuous across the weld interface. During the joining process, one of the materials to be joined acts as the anode and the other acts as the cathode. The anode and cathode are brought together with a concomitant discharge of a capacitor bank, creating an arc which melts the materials at the joining surfaces and welds them together (Fig. 1). As the electrodes impact, the arc is extinguished, and the molten interface cools at rates that can exceed 106 K/s. This process results in reduced porosity in the fusion zone, a fine-grained weldment, and a reduced tendency for hot cracking.At the U.S. Bureau of Mines, we are currently examining the possibilities of using capacitor discharge welding to join dissimilar metals, metals to intermetallics, and metals to conductive ceramics. In this particular study, we will examine the microstructural characteristics of iron-aluminum welds in detail, focussing our attention primarily on interfaces produced during the rapid solidification process.

Transmission Electron Microscopic Observations of Al3Li and Al3Ti Precipitation in A Rapidly Solidified Al-3Li-0.2Ti ALLOY

1980 ◽  
Vol 38 ◽  
pp. 336-337
Author(s):  
J. E. O’Neal ◽  
K. K. Sankaran ◽  
S. M. L. Sastry
Keyword(s):  
Rapid Solidification ◽  
Metallic Substrate ◽  
Deformation Characteristics ◽  
Phase Decomposition ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Supersaturated Solid Solutions ◽  
Transmission Electron Microscopic ◽  
Rapidly Solidified ◽  
Microstructural Homogeneity

Rapid solidification of a molten, multicomponent alloy against a metallic substrate promotes greater microstructural homogeneity and greater solid solubility of alloying elements than can be achieved by slower-cooling casting methods. The supersaturated solid solutions produced by rapid solidification can be subsequently annealed to precipitate, by controlled phase decomposition, uniform 10-100 nm precipitates or dispersoids. TEM studies were made of the precipitation of metastable Al3Li(δ’) and equilibrium AL3H phases and the deformation characteristics of a rapidly solidified Al-3Li-0.2Ti alloy.

Boiling Under Microgravity Conditions

2002 ◽  
Author(s):  
Vijay K. Dhir
Keyword(s):  
Microgravity Conditions

Balance for measuring mass under microgravity conditions

AIAA Journal ◽  
2001 ◽  
Vol 39 ◽  
pp. 455-457 ◽  
Author(s):  
Yusaku Fujii ◽  
Hiroyuki Fujimoto ◽  
Ritsu Watanabe ◽  
Yukinobu Miki
Keyword(s):  
Microgravity Conditions

Dendritic solidification under microgravity conditions

1988 ◽  
Author(s):  
M. GLICKSMAN ◽  
R. HAHN ◽  
T. LOGRASSO ◽  
S. TIRMIZI ◽  
E. WINSA
Keyword(s):  
Dendritic Solidification ◽  
Microgravity Conditions

Sedimentation of heavy crystal particles under microgravity conditions

1998 ◽  
Author(s):  
Andreas Alexandrou ◽  
Nikos Gatsonis ◽  
Hui Shi ◽  
Albert Sacco
Keyword(s):  
Microgravity Conditions

THYRAPID PM4 ESH

Alloy Digest ◽  
1995 ◽  
Vol 44 (6) ◽  
Keyword(s):  
Wear Resistance ◽  
Physical Properties ◽  
Surface Treatment ◽  
Rapid Solidification ◽  
Cold Work ◽  
Heat Treating ◽  
Bend Strength

Abstract THYRAPID PM4 ESH is manufactured by the rapid solidification of powder and augmented by Electro Slag Heating. Good wear resistance and toughness lead to cold work punch and die applications. This datasheet provides information on composition, physical properties, hardness, elasticity, and bend strength. It also includes information on heat treating, machining, and surface treatment. Filing Code: TS-539. Producer or source: Thyssen Specialty Steels Inc.

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