Preparation of Refractory Castable for High-Temperature Zone of the Alumina Kiln

2011 ◽  
Vol 217-218 ◽  
pp. 1229-1234
Author(s):  
Xin Xin Cao ◽  
Jian Guo Liao ◽  
Xiao Fang He ◽  
Ling Li Zhu ◽  
Rui Na Wang ◽  
...  

The cChromic shaped bricks have been used as the refractory lining in alumina kiln for long time, whose service life is about 120~250 days. Besides the short working time, the environmental pollution led to by the chromic component is also serious. In this thesispaper (thesis 是硕士论文), some materials are were chosen based on the actual situation of the usage of the refractory lining in the current alumina kiln. The choosing principals are were the extensive source and the relatively low price. Finally, a new formula of the refractory castable is was acquired based on the orthogonal test and has passed the properties testing.

Author(s):  
Firoz Alam ◽  
Reza N. Jazar

Fibre Reinforced Plastics (FRPs) generally have greater advantages over conventional materials for their structural properties. However, the service life can significantly be shortened if the fibre reinforced plastics are exposed to adverse environmental conditions especially acid vapour, humidity and high temperature. In many chemical industrial plants in Australia and elsewhere fibre reinforced plastic gratings are used as structural components of stairs and passages where they are subjected to varying degrees of fluosilicic acid, a byproduct of the industrial manufacturing process. As currently no experimental data on the effects of fluosilicic acid on FRPs is available in the public domain, it is difficult to predict the service life of FRPs with some certainty. In order to understand the structural strength of fluosilicic acid exposed FRPs, an experimental study was undertaken. A series of specimens from various locations of a chemical plan in Australia were acquired and studied. Some new specimens (not exposed to acid, humidity and high temperature) were also studied to provide a benchmark for the comparison. The results indicated that the long time exposure to harsh environment and acid vapour can significantly deteriorate the flexural strength and service life of FRPs.


Author(s):  
M. G. Burke ◽  
M. N. Gungor ◽  
M. A. Burke

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.


Alloy Digest ◽  
1989 ◽  
Vol 38 (1) ◽  

Abstract UNS NO6455 is a nickel-chromium-molybdenum alloy with outstanding high-temperature stability as shown by high ductility and corrosion resistance even after long-time aging in the range 1200-1900 F. The alloy also has excellent resistance to stress-corrosion cracking and to oxidizing atmospheres up to 1900 F. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-367. Producer or source: Nickel and nickel alloy producers.


Alloy Digest ◽  
1987 ◽  
Vol 36 (7) ◽  

Abstract UNS No. R54620 is an alpha-beta titanium alloy. It has an excellent combination of tensile strength, creep strength, toughness and high-temperature stability that makes it suitable for service to 1050 F. It is recommended for use where high strength is required. It has outstanding advantages for long-time use at temperatures to 800 F. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and bend strength as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ti-86. Producer or source: Titanium alloy mills.


2007 ◽  
Vol 353-358 ◽  
pp. 1765-1768
Author(s):  
Hong Fei Sun ◽  
Can Ming Wang ◽  
Qiang Song ◽  
Qiong Qiong Yan

Abrasion mechanism of thermocouple cannula is studied in this article. For different working position and condition, different material should be selected to ensure the working characteristics of thermocouple cannula. Several protection methods were introduced to prolong the sevice life of thermocouple cannula. 1. M-Al series intermetallic compound coating protection method. 2. Metal/ceramic compound coating protection method. 3. Development of new abrasion-resisting material for high temperature according to some special work conditions of thermocouple cannula. With the adoption of those new technologies, thermocouple cannula’s service life can be prolonged to 3~5 times of that untreated.


2002 ◽  
Vol 333 (1-2) ◽  
pp. 165-169 ◽  
Author(s):  
Y.Q Zhao ◽  
H.L Qu ◽  
K.Y Zhu ◽  
H Wu ◽  
C.L Liu ◽  
...  

2000 ◽  
Vol 655 ◽  
Author(s):  
Fengyan Zhang ◽  
Sheng Teng Hsu ◽  
Jer-shen Maa ◽  
Yoshi Ono ◽  
Ying Hong ◽  
...  

AbstractIr-Ta-O composite bottom electrode has extraordinary high temperature stability. It can maintain good conductivity and integrity even after 5min annealing at 1000 °C in oxygen ambient. The thermal stability of Ir-Ta-O on different substrates has been studied. It shows that Ir-Ta-O is also very stable on Si and SiO2 substrates. No hillock formation and peelings of the bottom electrode were observed after high temperature and long time annealing in O2 ambient. SEM, TEM, XRD, and AES have been used to characterize the Ir-Ta-O film and the interfaces between Ir-Ta-O bottom electrode and Si or SiO2 substrate. The composition and conductivity changes of the electrode during oxygen ambient annealing and the interdiffusion issue will be discussed. Furthermore, Ir-Ta-O/SiO2/Si capacitor with 30Å gate oxide was fabricated and the C-V and I-V characteristics were measured to confirm the stability of Ir-Ta-O on thin gate oxide.


1991 ◽  
Vol 240 ◽  
Author(s):  
G. Marrakchi ◽  
A. Kalboussi ◽  
G. Guillot ◽  
M. Ben Salem ◽  
H. Maaref ◽  
...  

ABSTRACTThe effects of high temperature isothermal annealing on the electrical properties of donor and acceptor defects in n-type LEC GaAs are investigated. The annealing experiments are performed under As-rich atmosphere at 1000°C for 1–4 and 16 hours followed by a very quick quenching into cold water of the quartz ampoules containing the samples. The donor and acceptor levels are detected respectively by standard (DLTS) and optical (ODLTS) deep level spectroscopy. DLTS results show the presence of one single donor level present in unannealed and annealed samples at Ec - 0.79eV which is identified as the well known electron trap EL2 Only the sample annealed for 16 hs exhibits the presence of a new electron trap named TAI at Ec - 0.32eV. The appearance of TAI is correlated in one hand with the evolution of EL2 concentration and in the other hand to the effect of long duration (16 hs) of the treatment. For acceptor levels, two hole traps HT1 and HT2 are detected respectively at EV + 0.18 eV and EV+ 0.28 eV. HT1 is detected only in samples annealed for 4 and 16 hs and HT2 is detected in all studied samples. Photoluminescence (PL) measurements show the presence of the 1.44 eV band corresponding to gallium antisite GaAs defect. This band observed in unannealed and annealed samples shows that GaAs remains stable even after thermal annealing at lOOO°C for 16 hs and it is correlated with the presence of HT2.


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