Tribological and interfacial phenomena in Al2O3/SiC and SiC/SiC couples at high temperature

1989 ◽  
Vol 5 (4) ◽  
pp. 223-228 ◽  
Author(s):  
P. Boch ◽  
F. Platon ◽  
G. Kapelski
Keyword(s):  
High Temperature ◽  
Interfacial Phenomena

Interface Stabilized Nanoscale Quasi-Liquid Films

2009 ◽  
Vol 17 (4) ◽  
pp. 22-27 ◽  
Author(s):  
Jian Luo ◽  
Shen J. Dillon ◽  
Martin P. Harmer
Keyword(s):  
High Temperature ◽  
Binary Systems ◽  
Liquid Films ◽  
Interfacial Phenomena ◽  
Metallic Materials ◽  
Average Composition ◽  
Free Surfaces ◽  
Mechanical And Physical Properties ◽  
Interfacial Films ◽  
Equilibrium Thickness

A unique class of impurity-based quasi-liquid films has been widely observed at free surfaces, grain boundaries (GBs), and hetero-phase interfaces in ceramic and metallic materials (Figure 1). These nanometer-thick interfacial films can be alternatively understood to be: (a) quasi-liquid layers that adopt an “equilibrium” thickness in response to a balance of attractive and repulsive interfacial forces (in a high-temperature colloidal theory) or (b) multilayer adsorbates with thickness and average composition set by bulk dopant activities [1–2]. In several model binary systems, such quasi-liquid, interfacial films are found to be thermodynamically stable well below the bulk solidus lines, provoking analogies to the simpler interfacial phenomena of premelting in unary systems [3] and prewetting in binary de-mixed liquids [4]. These interfacial films exhibit structures and compositions that are neither observed nor stable as bulk phases, as well as transport, mechanical, and physical properties that are markedly different from bulk phases.

Effect of Silica on High-Temperature Interfacial Phenomena of Monolithic Refractories with Al Alloy

2008 ◽  
Vol 39 (2) ◽  
pp. 331-339 ◽  
Author(s):  
Pramod Koshy ◽  
Sushil Gupta ◽  
Veena Sahajwalla ◽  
Phil Edwards
Keyword(s):  
High Temperature ◽  
Interfacial Phenomena ◽  
Al Alloy

High-temperature capillarity and interfacial phenomena

2005 ◽  
Vol 9 (4-5) ◽  
pp. 149-151 ◽  
Author(s):  
Natalia Sobczak ◽  
Mrityunjay (Jay) Singh ◽  
Rajiv Asthana
Keyword(s):  
High Temperature ◽  
Interfacial Phenomena ◽  
Temperature Capillarity

Interfacial phenomena in high temperature processes

2005 ◽  
Vol 40 (9-10) ◽  
pp. 2403-2409 ◽  
Author(s):  
K. C. Mills ◽  
E. D. Hondros ◽  
Zushu Li
Keyword(s):  
High Temperature ◽  
Interfacial Phenomena ◽  
High Temperature Processes

Influence of Thermo-Mechanical Processing on the Microstructure of Beryllia Dispersed Nickel Alloys

1973 ◽  
Vol 31 ◽  
pp. 184-185
Author(s):  
M.S. Grewal ◽  
S.A. Sastri ◽  
N.J. Grant
Keyword(s):  
High Temperature ◽  
Nickel Alloys ◽  
Thermomechanical Processing ◽  
Cold Work ◽  
High Temperature Strength ◽  
Strengthening Effect ◽  
Mechanical Processing ◽  
Uniform Dispersion ◽  
Oxide Particles ◽  
Nickel Base

Currently there is a great interest in developing nickel base alloys with fine and uniform dispersion of stable oxide particles, for high temperature applications. It is well known that the high temperature strength and stability of an oxide dispersed alloy can be greatly improved by appropriate thermomechanical processing, but the mechanism of this strengthening effect is not well understood. This investigation was undertaken to study the dislocation substructures formed in beryllia dispersed nickel alloys as a function of cold work both with and without intermediate anneals. Two alloys, one Ni-lv/oBeo and other Ni-4.5Mo-30Co-2v/oBeo were investigated. The influence of the substructures produced by Thermo-Mechanical Processing (TMP) on the high temperature creep properties of these alloys was also evaluated.

Application of TEM to Deformation, Wear, and Fracture of Ceramics

1974 ◽  
Vol 32 ◽  
pp. 472-473
Author(s):  
B. J. Hockey
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Mechanical Behavior ◽  
Brittle Materials ◽  
High Temperature Strength ◽  
Wide Range ◽  
Corrosive Environments ◽  
Further Development

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.

Lattice Imaging of Grain Boundaries in Ceramics

1977 ◽  
Vol 35 ◽  
pp. 114-115
Author(s):  
D. R. Clarke ◽  
G. Thomas
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Silicon Nitride ◽  
Grain Boundaries ◽  
High Temperature Strength ◽  
Current Interest ◽  
Lattice Imaging ◽  
Special Significance ◽  
Structural Applications ◽  
Refractory Ceramics

Grain boundaries have long held a special significance to ceramicists. In part, this has been because it has been impossible until now to actually observe the boundaries themselves. Just as important, however, is the fact that the grain boundaries and their environs have a determing influence on both the mechanisms by which powder compaction occurs during fabrication, and on the overall mechanical properties of the material. One area where the grain boundary plays a particularly important role is in the high temperature strength of hot-pressed ceramics. This is a subject of current interest as extensive efforts are being made to develop ceramics, such as silicon nitride alloys, for high temperature structural applications. In this presentation we describe how the techniques of lattice fringe imaging have made it possible to study the grain boundaries in a number of refractory ceramics, and illustrate some of the findings.

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