High temperature mechanical and thermal stability of silicate matrix composites

1995 ◽  
Vol 5 (10-11) ◽  
pp. 1367-1378 ◽  
Author(s):  
S. Sutherland ◽  
K.P. Plucknett ◽  
M.H. Lewis
2009 ◽  
Vol 467 (1-2) ◽  
pp. 135-141 ◽  
Author(s):  
Lv Xiao ◽  
Wei Jie Lu ◽  
Yun Gang Li ◽  
Ji Ning Qin ◽  
Di Zhang

Author(s):  
Shiro Fujishiro ◽  
Harold L. Gegel

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


2001 ◽  
Vol 670 ◽  
Author(s):  
Min-Joo Kim ◽  
Hyo-Jick Choi ◽  
Dae-Hong Ko ◽  
Ja-Hum Ku ◽  
Siyoung Choi ◽  
...  

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.


2005 ◽  
Vol 891 ◽  
Author(s):  
Kil Jin Han ◽  
Yu Jung Cho ◽  
Soon Young Oh ◽  
Yong Jin Kim ◽  
Won Jae Lee ◽  
...  

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.


2004 ◽  
Vol 45 (5) ◽  
pp. 327-332 ◽  
Author(s):  
V. V. Kolomeitsev ◽  
S. A. Suvorov ◽  
E. F. Kolomeitseva

2021 ◽  
Vol 15 (2) ◽  
pp. 164-169
Author(s):  
Jian Gu ◽  
Sea-Hoon Lee ◽  
Daejong Kim ◽  
Hee-Soo Lee ◽  
Jun-Seop Kim

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.


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