Ablation behavior of SiC/ZrB2 ultra-high temperature ceramic coatings by solid shielding shrouded plasma spray for high-temperature applications (temperature above 2000 °C)

2020 ◽  
Vol 403 ◽  
pp. 126271 ◽  
Author(s):  
Shahla Torabi ◽  
Zia Valefi ◽  
Naser Ehsani
Keyword(s):  
High Temperature ◽  
Plasma Spray ◽  
Ceramic Coatings ◽  
Shrouded Plasma Spray ◽  
Ultra High Temperature ◽  
Temperature Applications

Effects of heat treatments on oxidation resistance and mechanical properties of ultra high temperature ceramic coatings

2008 ◽  
Vol 202 (18) ◽  
pp. 4394-4398 ◽  
Author(s):  
Mario Tului ◽  
Stefano Lionetti ◽  
Giovanni Pulci ◽  
Elviro Rocca ◽  
Teodoro Valente ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Oxidation Resistance ◽  
Ceramic Coatings ◽  
Heat Treatments ◽  
Ultra High Temperature

scholarly journals Thermophysical Properties of Rh3X for Ultra-High Temperature Applications

2006 ◽  
Vol 50 (2) ◽  
pp. 69-76 ◽  
Author(s):  
By Yoshihiro Terada ◽  
Kenji Ohkubo ◽  
Seiji Miura ◽  
Mohri Tetsuo
Keyword(s):  
High Temperature ◽  
Thermophysical Properties ◽  
Ultra High Temperature ◽  
Temperature Applications

Stability of TaC precipitates in a Co–Re-based alloy being developed for ultra-high-temperature applications

2016 ◽  
Vol 49 (4) ◽  
pp. 1253-1265 ◽  
Author(s):  
Ralph Gilles ◽  
Debashis Mukherji ◽  
Lukas Karge ◽  
Pavel Strunz ◽  
Premysl Beran ◽  
...  
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Gas Turbines ◽  
Volume Fraction ◽  
Turbine Blades ◽  
Alloy Development ◽  
Carbide Phases ◽  
Ultra High Temperature ◽  
Temperature Applications

Co–Re alloys are being developed for ultra-high-temperature applications to supplement Ni-based superalloys in future gas turbines. The main goal of the alloy development is to increase the maximum service temperature of the alloy beyond 1473 K,i.e.at least 100 K more than the present single-crystal Ni-based superalloy turbine blades. Co–Re alloys are strengthened by carbide phases, particularly the monocarbide of Ta. The binary TaC phase is stable at very high temperatures, much greater than the melting temperature of superalloys and Co–Re alloys. However, its stability within the Co–Re–Cr system has never been studied systematically. In this study an alloy with the composition Co–17Re–23Cr–1.2Ta–2.6C was investigated using complementary methods of small-angle neutron scattering (SANS), scanning electron microscopy, X-ray diffraction and neutron diffraction. Samples heat treated externally and samples heatedin situduring diffraction experiments exhibited stable TaC precipitates at temperatures up to 1573 K. The size and volume fraction of fine TaC precipitates (up to 100 nm) were characterized at high temperatures within situSANS measurements. Moreover, SANS was used to monitor precipitate formation during cooling from high temperatures. When the alloy is heated the matrix undergoes an allotropic phase transformation from the ∊ phase (hexagonal close-packed) to the γ phase (face-centred cubic), and the influence on the strengthening TaC precipitates was also studied within situSANS. The results show that the TaC phase is stable and at these high temperatures the precipitates coarsen but still remain. This makes the TaC precipitates attractive and the Co–Re alloys a promising candidate for high-temperature application.

scholarly journals Microstructure and Mechanical Properties of Vacuum Plasma Sprayed HfC, TiC, and HfC/TiC Ultra-High-Temperature Ceramic Coatings

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 124
Author(s):  
Ho Seok Kim ◽  
Bo Ram Kang ◽  
Seong Man Choi
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Single Layer ◽  
Ceramic Coatings ◽  
Hafnium Carbide ◽  
Vacuum Plasma Spraying ◽  
Vacuum Plasma ◽  
Coating Layers ◽  
Hardness Values ◽  
Ultra High Temperature

To improve the oxidation resistance of carbon composites at high temperatures, hafnium carbide (HfC) and titanium carbide (TiC) ultra-high-temperature ceramic coatings were deposited using vacuum plasma spraying. Single-layer HfC and TiC coatings and multilayer HfC/TiC coatings were fabricated and compared. The microstructure and composition of the fabricated coatings were analyzed using field-emission scanning electron microscopy and energy dispersive X-ray spectroscopy. The coating thicknesses of the HfC and TiC single-layer coatings were 165 µm and 140 µm, respectively, while the thicknesses of the HfC and TiC layers in the HfC/TiC multi-layer coating were 40 µm and 50 µm, respectively. No oxides were observed in any of the coating layers. The porosity was analyzed from cross-sectional images of the coating layers obtained using optical microscopy. Five random areas for each coating layer specimen were analyzed, and average porosity values of approximately 16.8% for the HfC coating and 22.5% for the TiC coating were determined. Furthermore, the mechanical properties of the coating layers were investigated by measuring the hardness of the cross section and surface roughness. The hardness values of the HfC and TiC coatings were 1650.7 HV and 753.6 HV, respectively. The hardness values of the HfC and TiC layers in the multilayer sample were 1563.5 HV and 1059.2 HV, respectively. The roughness values were 5.71 µm for the HfC coating, 4.30 µm for the TiC coating, and 3.32 µm for the HfC/TiC coating.

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