scholarly journals Enhancing High-Temperature Strength and Thermal Stability of Al2O3/Al Composites by High-Temperature Pre-treatment of Ultrafine Al Powders

2020 ◽  
Vol 33 (7) ◽  
pp. 913-921 ◽  
Author(s):  
Yu-Ning Zan ◽  
Yang-Tao Zhou ◽  
Xiao-Nan Li ◽  
Guo-Nan Ma ◽  
Zhen-Yu Liu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
High Temperature Strength ◽  
Pre Treatment ◽  
Thermal Stability Of

High Temperature Characteristics of Unidirectionally Solidified Al2O3/GAP Eutectic Composites with a Novel Microstructure

2012 ◽  
Vol 706-709 ◽  
pp. 246-251 ◽  
Author(s):  
Yoshiharu Waku ◽  
Hideki Ohtsubo ◽  
Narihito Nakagawa ◽  
Hideyuki Yasuda
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Single Crystal ◽  
Ceramic Composites ◽  
Chain Structure ◽  
High Temperature Strength ◽  
Temperature Characteristics ◽  
Air Atmosphere ◽  
Very High ◽  
Thermal Stability Of

Much attention has been paid to unidirectionally solidified ceramic composites as candidates for high-temperature structural materials. We have recently developed potential ceramic eutectics, which are named Melt Growth Composites (MGC). The Al2O3/GAP(GdAlO3) binary MGC has a novel microstructure, in which continuous networks of single-crystal Al2O3 phases and single-crystal GAP phases interpenetrate without grain boundaries. Chain structure in the Al2O3/GAP binary system is formed due to the frequent branching of both phases resulted in the entangled structure. Therefore, the Al2O3/GAP binary MGC has excellent high-temperature characteristics in the air atmosphere at very high temperatures. In the paper, high temperature strength, thermal stability of microstructure and strength, and fracture toughness of the Al2O3/GAP binary MGC are reported.

High-temperature strength and thermal stability of a unidirectionally solidified Al2O3/YAG eutectic composite

1998 ◽  
Vol 33 (5) ◽  
pp. 1217-1225 ◽  
Author(s):  
Y WAKU ◽  
N NAKAGAWA ◽  
T WAKAMOTO ◽  
H OHTSUBO ◽  
K SHIMIZU ◽  
...  
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
High Temperature Strength ◽  
Eutectic Composite ◽  
Thermal Stability Of

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

Increased Thermal Stability of Co-silicide Using Co-Ta Alloy Films

2001 ◽  
Vol 670 ◽  
Author(s):  
Min-Joo Kim ◽  
Hyo-Jick Choi ◽  
Dae-Hong Ko ◽  
Ja-Hum Ku ◽  
Siyoung Choi ◽  
...  
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Grain Boundary ◽  
Reaction Rate ◽  
Boundary Migration ◽  
Grain Boundary Migration ◽  
Alloy Films ◽  
Post Annealing ◽  
Alloy Process ◽  
Thermal Stability Of

ABSTRACTThe silicidation reactions and thermal stability of Co silicide formed from Co-Ta/Si systems have been investigated. In case of Co-Ta alloy process, the formation of low resistive CoSi2phase is delayed to about 660°C, as compared to conventional Co/Si system. Moreover, the presence of Ta in Co-Ta alloy films reduces the silicidation reaction rate, resulting in the strong preferential orientation in CoSi2 films. Upon high temperature post annealing in the furnace, the sheet resistance of Co-silicide formed from Co/Si systems increases significantly, while that of Co-Ta/Si systems maintains low. This is due to the formation of TaSi2 at the grain boundaries and surface of Co-silicide films, which prevents the grain boundary migration thereby slowing the agglomeration. Therefore, from our research, increased thermal stability of Co-silicide films was successfully obtained from Co-Ta alloy process.

Thermal stability of nickel-cobalt multilayer silicide

2005 ◽  
Vol 891 ◽  
Author(s):  
Kil Jin Han ◽  
Yu Jung Cho ◽  
Soon Young Oh ◽  
Yong Jin Kim ◽  
Won Jae Lee ◽  
...  
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Depth Profile ◽  
Ternary Phase ◽  
Nickel Silicide ◽  
Composition Gradient ◽  
Cobalt Silicide ◽  
Nickel Cobalt ◽  
Thermal Stability Of ◽  
Xps Depth Profile

ABSTRACTIn this study, we have investigated the structure of nickel-cobalt silicide to understand its behavior at high temperature. Nickel-cobalt silicide was formed after two-step RTP at 500°C and 700°C respectively. We could observe by TEM that nickel-cobalt silicide consists of a structure which seems to be a Ni-Co-Si ternary phase. No nickel silicide phases and cobalt silicide phases were detected in nickel-cobalt silicide by XRD. From XPS depth profile, we could confirm that there is a cobalt composition gradient along the silicide.

Thermal stability of high-temperature materials. Part 1

2004 ◽  
Vol 45 (5) ◽  
pp. 327-332 ◽  
Author(s):  
V. V. Kolomeitsev ◽  
S. A. Suvorov ◽  
E. F. Kolomeitseva
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
High Temperature Materials ◽  
Thermal Stability Of

scholarly journals Improved thermal stability of SiCf/SiC ceramic matrix composites fabricated by PIP process

2021 ◽  
Vol 15 (2) ◽  
pp. 164-169
Author(s):  
Jian Gu ◽  
Sea-Hoon Lee ◽  
Daejong Kim ◽  
Hee-Soo Lee ◽  
Jun-Seop Kim
Keyword(s):  
Thermal Stability ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Matrix Composites ◽  
Sic Fiber ◽  
Sic Ceramic ◽  
Different Temperatures ◽  
Pre Treatment ◽  
Thermal Deterioration ◽  
Thermal Stability Of

Improvement of the thermal stability of continuous SiC fiber reinforced SiC ceramic matrix composites (SiCf/SiC CMC) by the pre-treatment of SiC fillers and the suppression of oxidation during polymer impregnation and pyrolysis (PIP) process were investigated. Dense SiCf/SiC CMCs were fabricated using the slurry infiltration and PIP process under a purified argon atmosphere. Structure and mechanical properties of the SiCf/SiC CMC heated at different temperatures were evaluated. The flexural strength of the SiCf/SiC CMC decreased only 15.3%after heating at 1400 ?C, which exhibited a clear improvement compared with the literature data (49.5% loss), where severe thermal deterioration of SiCf/SiC composite occurred at high temperatures by the crystallization and decomposition of the precursor-derived ceramic matrix. The thermal stability of the SiCf/SiC CMC fabricated by PIP process was improved by the pre-treatment of SiC fillers for removing oxides and the strict atmosphere control to prevent oxidation.

scholarly journals Changes in thermal stability of lignocelluloses waste aggregates long-term incorporated in composite

2021 ◽  
Vol 900 (1) ◽  
pp. 012042
Author(s):  
N Stevulova ◽  
A Estokova
Keyword(s):  
Thermal Stability ◽  
Alkaline Treatment ◽  
Cement Matrix ◽  
Scanning Calorimetry ◽  
Alkali Ions ◽  
Thermal Gravimetry ◽  
Pre Treatment ◽  
Surface Modified ◽  
Thermal Stability Of

Abstract This paper is addressed to comparative study of changes in thermal stability of surface-modified hemp-hurds aggregates long-term incorporated in bio-aggregate-based composites with the original ones before their integration into alternative binder matrix. In this study, the effectiveness of alkaline treatment of hemp hurds compared to the raw bio-aggregates as well as in relation to their behaviour when they are long-term incorporated in the MgO-cement environment is investigated. The differences in the thermal behaviour of the samples are explained by the changed structure of hemp hurds constituents due to the pre-treatment and long-term action of the alternative binder components on the bio-aggregates. Alkaline treatment increases thermal stability of hemp hurds compared to raw sample. Also long-term incorporation of hemp hurds in MgO-cement matrix had a similar effect in case of alkaline modified bio-aggregates. The more alkali ions present in the structure of hemp hurdssamples, the more ash is formed during their thermal decomposition studied by thermal gravimetry (TG) and differential scanning calorimetry (DSC).

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