Dual-phase magnesia-zirconia ceramics with strength retention at elevated temperatures

1989 ◽  
Vol 24 (11) ◽  
pp. 3855-3864 ◽  
Author(s):  
Thomas C. Yuan ◽  
G. V. Srinivasan ◽  
Jan Fong Jue ◽  
Anil V. Virkar
Keyword(s):  
Elevated Temperatures ◽  
Dual Phase ◽  
Zirconia Ceramics ◽  
Strength Retention

Magnetron Sputtered Intermetallic Al2Au and Al-Zr-Y Coatings for the Oxidation Protection of γ-TiAl

2006 ◽  
Vol 980 ◽  
Author(s):  
Martin Moser ◽  
Paul Heinz Mayrhofer ◽  
Reinhold Braun
Keyword(s):  
Elevated Temperatures ◽  
Turbine Blades ◽  
Mass Gain ◽  
Coarse Grained ◽  
Dual Phase ◽  
Scanning Calorimetry ◽  
Protective Oxide ◽  
Oxidation Protection ◽  
Good Oxidation Resistance ◽  
Phase Intermetallic

AbstractAl-based intermetallic coatings are widely used as bond coats and for oxidation protection of turbine blades and engine components. Here we present and discuss the structural and thermal properties of novel unbalanced-magnetron sputtered Al-based coatings (single-phase intermetallic Al2Au, binary Al-Zr, and nano-structured Al-Zr-Y) developed to protect gamma-TiAl from environmental attack at elevated temperatures. Al-Zr films exhibit a coarse-grained dual-phase Al3Zr2-Al2Zr structure and are nano-structured by alloying with ~5, 10, and 14 at% Y.Combined dynamic differential-scanning calorimetry and thermogravimetric analyses up to a temperature of 1150 °C reveal that the Al2Au film is very stable with only marginal mass gain from oxidation found between 800 and 1000 °C. High temperature X-ray diffraction shows that this coating retains its (311) texture up to 900 °C where Al2O3 formation leads to the depletion of Al in Al2Au and subsequently the precipitation of intermetallic AlAu. When gamma-TiAl is coated with Al2Au and exposed to cyclic oxidation tests at 750 and 850 °C good oxidation resistance is obtained as a protective oxide layer is formed.Dual-phase Al3Zr2-Al2Zr coatings form ZrO2 and Al2O3 in oxidizing atmosphere. However, the phase transition from monoclinic (m-)ZrO2 to tetragonal (t-)ZrO2 with the accompanying volume change causes flaking of the oxide. Yttrium addition to the Al-Zr films stabilizes the cubic (c-) and t-ZrO2 and hence avoids the fatal tetragonal-monocline transformation. The thermally grown c-ZrO2 based oxides allow good adhesion to thermal barrier coatings which are themselves based on c-ZrO2.

Microstructure of Silicon Nitride Fibers at Elevated Temperatures

2017 ◽  
Vol 898 ◽  
pp. 1705-1711 ◽  
Author(s):  
Jun Zhe Li ◽  
Xun Sun ◽  
Hai Tao Liu ◽  
Hai Feng Cheng ◽  
Xiao Shan Zhang
Keyword(s):  
Heat Treatment ◽  
Silicon Nitride ◽  
Amorphous Silicon ◽  
Treatment Process ◽  
Elevated Temperatures ◽  
Heat Treatment Process ◽  
Amorphous Silicon Nitride ◽  
Heat Treated ◽  
Strength Retention ◽  
Heat Treated Temperature

The composition and microstructure of silicon nitride fibers after heat-treatment at elevated temperatures were investigated by XRD, NMR, XPS, SEM and TEM analyses. The results show that as-received fibers consisted of amorphous silicon nitride, and a little Si-C-O structure. During heat-treatment process, α-Si3N4 and β-Si3N4 formed resulting from the crystallization of amorphous silicon nitride, and the formation of β-SiC derived from the decomposition of Si-C-O structure. As heat-treated temperature increased from 1400oC to 1600oC, the above phenomenon become obvious, indicating that the fiber would possess high serving life with serving temperature lower than 1400oC. The tensile strength of fibers stays stable when heat-treated temperature was below 1200oC, while the strength retention of fibers sharply decreased to 50% after heat-treatment at 1400°C.

Studies on mechanical behavior of LSFT-CGO dual-phase membranes at elevated temperatures in ambient air and slightly reducing environments

2014 ◽  
Vol 40 (6) ◽  
pp. 7783-7790 ◽  
Author(s):  
Thangamani Nithyanantham ◽  
Somnath Biswas ◽  
Nagabhushana Nagendra ◽  
Sukumar Bandopadhyay
Keyword(s):  
Mechanical Behavior ◽  
Elevated Temperatures ◽  
Ambient Air ◽  
Dual Phase

ATI 720

Alloy Digest ◽  
2009 ◽  
Vol 58 (6) ◽  
Keyword(s):  
Solid Solution ◽  
Corrosion Resistance ◽  
Elevated Temperatures ◽  
Base Alloy ◽  
High Strength ◽  
Heat Treating ◽  
Nickel Base Alloy ◽  
Temperature Performance ◽  
Nickel Base ◽  
Strength Retention

Abstract ATI 720 is a nickel-base alloy, solid solution strengthened with tungsten and molybdenum and precipitation hardened with titanium and aluminum. The alloy combines high strength with metallurgical stability as demonstrated by excellent impact strength retention after long exposures at elevated temperatures. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-669. Producer or source: Allvac, An Allegheny Technologies Company.

scholarly journals Fabrication and characterization of dual phase magnesia–zirconia ceramics doped with plutonia

2006 ◽  
Vol 352 (1-3) ◽  
pp. 318-323 ◽  
Author(s):  
P.G. Medvedev ◽  
J.F. Jue ◽  
S.M. Frank ◽  
M.K. Meyer
Keyword(s):  
Dual Phase ◽  
Zirconia Ceramics ◽  
Fabrication And Characterization

Deformation behavior and constitutive model for dual-phase Mg–Li alloy at elevated temperatures

2016 ◽  
Vol 26 (2) ◽  
pp. 508-518 ◽  
Author(s):  
Guo-bing WEI ◽  
Xiao-dong PENG ◽  
Fa-ping HU ◽  
Amir HADADZADEH ◽  
Yan YANG ◽  
...  
Keyword(s):  
Constitutive Model ◽  
Deformation Behavior ◽  
Elevated Temperatures ◽  
Dual Phase
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