Oxidation Kinetics Of Mosi2 And Mosi2/Reinforcement Mixtures

1990 ◽  
Vol 213 ◽  
Author(s):  
P. J. Meschter
Keyword(s):  
High Temperature ◽  
Slow Growth ◽  
Matrix Composites ◽  
Vapor Species ◽  
Dry Air ◽  
Oxidation Study ◽  
High Temperature Materials ◽  
Mass Losses ◽  
Kinetics Of ◽  
Low Rate

ABSTRACTAn oxidation study of pure, dense MoSi 2 at 400-600°C and MoSi2/20 vol. % (TiB2, Al2O3, Nb) mixtures at 400–1200°C has been performed. Dense MoSi2 does not fail catastrophically (“pest”) in dry air, wet air, or oxygen, and oxidizes heavily only near 500°C. Heavy oxidation is related to the slow growth of a protective, amorphous SiO2 layer; a low rate of Mo removal as vapor species; and cracking of an initially protective Mo9O26-SiO2 layer. Pre-oxidation of MoSi2 at 1200°C prevents subsequent heavy oxidation at 500°C. MoSi2/TiB2 and MoSi2/A12O3 mixtures oxidize more slowly than MoSi2 for T < 600°C and more rapidly for T > 600°C. Protective oxides are formed on MoSi2/reinforcement mixtures except at 500°C, for which high-temperature pre-oxidation is again effective. MoSi2/Nb mixtures suffer severe mass losses upon oxidation at both 500 and 1200°C owing to rapid oxidation of the Nb and spalling of the product Nb2O5 Only the latter case poses problems for the application of MoSi2-matrix composites as high-temperature materials.

The Ordered Phase Formation in Ti-Al-Ga Alloys

1970 ◽  
Vol 28 ◽  
pp. 440-441
Author(s):  
Shiro Fujishiro ◽  
Harold L. Gegel
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Titanium Alloys ◽  
Growth Kinetics ◽  
Stoichiometric Composition ◽  
Good Potential ◽  
Alpha Titanium ◽  
Cold Rolled ◽  
Kinetics Of ◽  
Thermal Stability Of

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization

Microstructural characterization of plasma-processed Ti-Al metal matrix composites

1989 ◽  
Vol 47 ◽  
pp. 552-553
Author(s):  
M. G. Burke ◽  
M. N. Gungor ◽  
M. A. Burke
Keyword(s):  
High Temperature ◽  
Titanium Aluminide ◽  
Plasma Processing ◽  
Microstructural Characterization ◽  
High Temperature Strength ◽  
Matrix Composites ◽  
Intermetallic Matrix ◽  
Long Time ◽  
Strength And Stiffness ◽  
Intermetallic Matrix Composites

Intermetallic matrix composites are candidates for ultrahigh temperature service when light weight and high temperature strength and stiffness are required. Recent efforts to produce intermetallic matrix composites have focused on the titanium aluminide (TiAl) system with various ceramic reinforcements. In order to optimize the composition and processing of these composites it is necessary to evaluate the range of structures that can be produced in these materials and to identify the characteristics of the optimum structures. Normally, TiAl materials are difficult to process and, thus, examination of a suitable range of structures would not be feasible. However, plasma processing offers a novel method for producing composites from difficult to process component materials. By melting one or more of the component materials in a plasma and controlling deposition onto a cooled substrate, a range of structures can be produced and the method is highly suited to examining experimental composite systems. Moreover, because plasma processing involves rapid melting and very rapid cooling can be induced in the deposited composite, it is expected that processing method can avoid some of the problems, such as interfacial degradation, that are associated with the relatively long time, high temperature exposures that are induced by conventional processing methods.

Thermochemical Protection of High Temperature Materials

2001 ◽  
Vol 8 (4) ◽  
pp. 231-241 ◽  
Author(s):  
J. Stricker ◽  
Y. Goldman ◽  
Genady Borodyanski
Keyword(s):  
High Temperature ◽  
High Temperature Materials

3D Structural Analysis of Selected High-Temperature Materials

2018 ◽  
Vol 55 (7) ◽  
pp. 424-446
Author(s):  
U. Jäntsch ◽  
M. Klimenkov ◽  
A. Möslang ◽  
F. Reinauer ◽  
J. Reiser ◽  
...  
Keyword(s):  
High Temperature ◽  
Structural Analysis ◽  
High Temperature Materials

ULTEM 6100, ULTEM 6200, ULTEM 6202

Alloy Digest ◽  
1990 ◽  
Vol 39 (7) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
Shear Strength ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
High Temperature Materials ◽  
Electrical Components

Abstract ULTEM 6100 and 6200 are glass reinforced and ULTEM 6202 is a mineral filled copolymer resin. For properties of the unreinforced resin, ULTEM 6000, see Alloy Digest P-27, June 1991. These are high temperature materials that are particularly suitable for military electrical components which must survive 200 C testing. This datasheet provides information on physical properties, hardness, tensile properties, and compressive and shear strength as well as fracture toughness. It also includes information on corrosion resistance. Filing Code: Cp-16. Producer or source: G. E. Plastics.

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