Microstructural characterization of nanostructured supersonic sprayed Ni–Sn coatings after wear tests at elevated temperature

2015 ◽  
Vol 106 (7) ◽  
pp. 750-757 ◽  
Author(s):  
Jan Kusinski ◽  
Slawomir Kac ◽  
Kazimierz Kowalski ◽  
Beata Dubiel ◽  
Stanislaw Dymek ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Microstructural Characterization ◽  
Wear Tests

Microstructural characterization of a Cr2Nb-Nb(Cr) microlaminate composite

1994 ◽  
Vol 52 ◽  
pp. 706-707
Author(s):  
M. Larsen ◽  
R. G. Rowe ◽  
D. W. Skelly
Keyword(s):  
High Temperature ◽  
Elevated Temperature ◽  
Metal Layer ◽  
Intermetallic Layer ◽  
Weight Ratio ◽  
Microstructural Characterization ◽  
Aircraft Engine ◽  
Intrinsic Defect ◽  
Lamellar Thickness

The thrust to weight ratio of an aircraft engine is limited by the density and elevated temperature performance of high temperature structural materials. Many material systems are currently under investigation as potential next generation engine materials. Microlaminate composites consisting of alternating layers of a ductile refractory metal for toughening and a high temperature intermetallic compound for elevated temperature strength have applicability in aircraft engine turbines. The lamellar thickness of such a composite must be small because the intrinsic defect size, a crack across the intermetallic layer, will be controlled by the intermetallic layer thickness. The microstructural characterization of a Cr2Nb-Nb(Cr) microlaminate composite produced by Magnetron® sputtering was carried out by cross-sectional TEM. Both the as-deposited composite and one heat treated at 1200°C for two hours were examined.Figure 1 shows a micrograph of the as-deposited composite. The metal and intermetallic layers are 2um thick. The metal layer has a composition in atomic percent of 95% Nb and 5% Cr.

DSC and TEM Study of Al-Cu-Mg-Ag Alloy Ageing at Low and Elevated Temperature

2011 ◽  
Vol 295-297 ◽  
pp. 1225-1229 ◽  
Author(s):  
Hong Wei Liu ◽  
Yon Gan Zhang ◽  
Jian Bo Zhang ◽  
Bao Hong Zhu ◽  
Feng Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Elevated Temperature ◽  
Differential Scanning Calorimeter ◽  
Microstructural Characterization ◽  
Ageing Temperature ◽  
Precipitation Sequence ◽  
Ω Phase ◽  
Transmission Electron

Microstructural characterization of Al-Cu-Mg-Ag alloy ageing at low and elevated temperature were investigated by differential scanning calorimeter (DSC) and transmission electron microscopy (TEM). The results show that the precipitation sequence is significantly influenced by the ageing temperature. With prolonging of ageing at 65°C, G.P. zones on the plane of {100}α separates out with no precipitation of Ω phase. After 10h ageing at 160°C,the phase of Ω separates out and dominant the microstructure, while a small quantity of θ′separates out as well.

Microstructural characterization of CoPtCr/Cr thin film disks by cross-section TEM and elongated probe micro-diffraction

1991 ◽  
Vol 49 ◽  
pp. 762-763
Author(s):  
M.A. Parker ◽  
K.E. Johnson ◽  
C. Hwang ◽  
A. Bermea
Keyword(s):  
Magnetic Recording ◽  
Electron Probe ◽  
Microstructural Characterization ◽  
Crystallographic Structure ◽  
Recording Media ◽  
Layer By Layer ◽  
Cross Sectional ◽  
New Techniques ◽  
Polished Side

We have reported the dependence of the magnetic and recording properties of CoPtCr recording media on the thickness of the Cr underlayer. It was inferred from XRD data that grain-to-grain epitaxy of the Cr with the CoPtCr was responsible for the interaction observed between these layers. However, no cross-sectional TEM (XTEM) work was performed to confirm this inference. In this paper, we report the application of new techniques for preparing XTEM specimens from actual magnetic recording disks, and for layer-by-layer micro-diffraction with an electron probe elongated parallel to the surface of the deposited structure which elucidate the effect of the crystallographic structure of the Cr on that of the CoPtCr.XTEM specimens were prepared from magnetic recording disks by modifying a technique used to prepare semiconductor specimens. After 3mm disks were prepared per the standard XTEM procedure, these disks were then lapped using a tripod polishing device. A grid with a single 1mmx2mm hole was then glued with M-bond 610 to the polished side of the disk.

Microstructural characterization of a rapidly solidified Al-Fe-V-Si alloy for elevated temperature applications

1988 ◽  
Vol 46 ◽  
pp. 550-551
Author(s):  
R. E. Franck ◽  
J. A. Hawk ◽  
G. J. Shiflet
Keyword(s):  
High Temperature ◽  
Elevated Temperature ◽  
Grain Growth ◽  
Volume Fraction ◽  
Microstructural Characterization ◽  
Second Phase ◽  
Microstructural Stability ◽  
Elevated Temperature Strength ◽  
Temperature Applications

Rapid solidification processing (RSP) is one method of producing high strength aluminum alloys for elevated temperature applications. Allied-Signal, Inc. has produced an Al-12.4 Fe-1.2 V-2.3 Si (composition in wt pct) alloy which possesses good microstructural stability up to 425°C. This alloy contains a high volume fraction (37 v/o) of fine nearly spherical, α-Al12(Fe, V)3Si dispersoids. The improved elevated temperature strength and stability of this alloy is due to the slower dispersoid coarsening rate of the silicide particles. Additionally, the high v/o of second phase particles should inhibit recrystallization and grain growth, and thus reduce any loss in strength due to long term, high temperature annealing.The focus of this research is to investigate microstructural changes induced by long term, high temperature static annealing heat-treatments. Annealing treatments for up to 1000 hours were carried out on this alloy at 500°C, 550°C and 600°C. Particle coarsening and/or recrystallization and grain growth would be accelerated in these temperature regimes.

Microstructural Characterization of Au-Ge-Ni based ohmic contacts to GaAs/AlGaAs modfet device

1987 ◽  
Vol 45 ◽  
pp. 326-327
Author(s):  
A.K. Rai ◽  
A.K. Petford-Long ◽  
A. Ezis ◽  
D.W. Langer
Keyword(s):  
Contact Resistance ◽  
Ohmic Contact ◽  
Ohmic Contacts ◽  
Microstructural Characterization ◽  
Almost Everywhere ◽  
Spacer Layer ◽  
Good Contact ◽  
The Relationship ◽  
Lower Contact

Considerable amount of work has been done in studying the relationship between the contact resistance and the microstructure of the Au-Ge-Ni based ohmic contacts to n-GaAs. It has been found that the lower contact resistivity is due to the presence of Ge rich and Au free regions (good contact area) in contact with GaAs. Thus in order to obtain an ohmic contact with lower contact resistance one should obtain a uniformly alloyed region of good contact areas almost everywhere. This can possibly be accomplished by utilizing various alloying schemes. In this work microstructural characterization, employing TEM techniques, of the sequentially deposited Au-Ge-Ni based ohmic contact to the MODFET device is presented.The substrate used in the present work consists of 1 μm thick buffer layer of GaAs grown on a semi-insulating GaAs substrate followed by a 25 Å spacer layer of undoped AlGaAs.

Microstructural characterization of a cast RENi5-based alloy

1993 ◽  
Vol 51 ◽  
pp. 1176-1177
Author(s):  
G. M. Micha ◽  
L. Zhang
Keyword(s):  
Electron Microscopy ◽  
Rare Earth ◽  
Microstructural Characterization ◽  
Binary Compound ◽  
Nickel Metal ◽  
Cast Material ◽  
Nickel Metal Hydride ◽  
Transmission Electron ◽  
Cast Condition

RENi5 (RE: rare earth) based alloys have been extensively evaluated for use as an electrode material for nickel-metal hydride batteries. A variety of alloys have been developed from the prototype intermetallic compound LaNi5. The use of mischmetal as a source of rare earth combined with transition metal and Al substitutions for Ni has caused the evolution of the alloy from a binary compound to one containing eight or more elements. This study evaluated the microstructural features of a complex commercial RENi5 based alloy using scanning and transmission electron microscopy.The alloy was evaluated in the as-cast condition. Its chemistry in at. pct. determined by bulk techniques was 12.1 La, 3.2 Ce, 1.5 Pr, 4.9 Nd, 50.2 Ni, 10.4 Co, 5.3 Mn and 2.0 Al. The as-cast material was of low strength, very brittle and contained a multitude of internal cracks. TEM foils could only be prepared by first embedding pieces of the alloy in epoxy.

Microstructural Characterization of Open-Pore Metal Foams of Pure Metals

2015 ◽  
Vol 52 (2) ◽  
pp. 83-107 ◽  
Author(s):  
B. S. Mocker ◽  
A. M. Matz ◽  
N. Jost ◽  
P. Krug
Keyword(s):  
Microstructural Characterization ◽  
Metal Foams ◽  
Pure Metals

Microstructural Characterization of Equiatomic CrFeNbNiV Alloy

2018 ◽  
Vol 72 (1) ◽  
pp. 111-121 ◽  
Author(s):  
A. Saikumaran ◽  
R. Mythili ◽  
S. Saroja ◽  
V. Srihari
Keyword(s):  
Microstructural Characterization
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