High-temperature creep properties of TATB-based polymer bonded explosives filled with multi-walled carbon nanotubes

RSC Advances ◽  
2015 ◽  
Vol 5 (27) ◽  
pp. 21376-21383 ◽  
Author(s):  
Congmei Lin ◽  
Jiahui Liu ◽  
Feiyan Gong ◽  
Guiyu Zeng ◽  
Zhong Huang ◽  
...  

The addition of 0.25 mass% MWCNTs is a simple and novel route for improving the creep resistance of TATB-based PBX.

2016 ◽  
Vol 680 ◽  
pp. 343-346 ◽  
Author(s):  
Yong Qiang Sun ◽  
Yong Li ◽  
Shuo Cao ◽  
Hao Bo Zhang ◽  
Chang He Gao ◽  
...  

High temperature creep properties of Al2O3-SiO2 ore (65% Al2O3 by mass percentage, abbreviation for Al2O3~65) was studied. The results show that the creep rates at 1300 °C × 50h, 1400 °C × 50h and 1500 °C × 50h were-0.89% ,- 1.75%, - 5.76%,respectively. At 1300 °C, ore has good creep resistance. As the temperature increases, the high temperature creep resistance of Al2O3 ~ 65 bauxite ore is significantly reduced. Creep process can be divided into two stages: when the time t <30h, the sample are in the densification process; after 30 hours, the creep properties show that the relationship between time and the creep rate is linear. At 1300 °C, the absolute value which is the slope of the linear relationship is smaller, exhibited an excellent high-temperature creep resistance. The loading softening-temperature of Al2O3 ~ 65 bauxite ore is 1343 °C. The Sample phase and microstructure are characterized by X-ray diffraction and scanning electron microscopy (SEM). The results show that mullite reticular is formed in sample at 1300 °C; at this point, TiO2 mostly exist as Rutile. At 1400 °C and 1500 °C, TiO2 mostly exist as Aluminum titanate, Corundum phase portion into mullite.


2016 ◽  
Vol 680 ◽  
pp. 347-351
Author(s):  
Shuo Cao ◽  
Yong Li ◽  
Jia Lin Sun ◽  
Hao Bo Zhang ◽  
Yong Qiang Sun ◽  
...  

This paper studied the high temperature creep properties of high-alumina bauxite (the mass fraction of Al2O3 in the new ore is about 78, the following abbreviations for Al2O3~78). The results indicated that the Al2O3~78 high-alumina bauxite mainly are corundum phase after high temperature sintered.When the temperature is 1100°C, corundum exists as crystal phase and the connections between grains are directly. The creep resistance of samples is very good at this temperature and the creep rate of 50 hours heat preservation is-0.266%. When the temperature is 1200°C, liquid phase starts to produce in a large number and the creep rate in 50 hours heat preservation is-1.589%. When the temperature is 1300°C, because of the further increase on the amount of liquid phase and wetting coated corundum particle, the direct connections between corundum particles are broken and the creep resistance is greatly reduced, the creep rate in 50 hours heat preservation is-4.088%. The creep curve fitting after 25 hours indicated that the creep property shows linear relations in three different temperatures after 25 hours. When the temperature is 1200°C and 1300°C, the creep variables arise rapidly in linear which declare the creep resistance of corundum is poor and increasing with temperature go up, more corundum phase is covered by glass phase and the creep resistance reduces dramatically.


2013 ◽  
Vol 716 ◽  
pp. 373-378
Author(s):  
Qian Zhang ◽  
Xin Bao Gao ◽  
Tian Peng Li

Carbon nanotube/expanded graphite composite material was prepared by expanding the mixture of multi-walled carbon nanotubes and expansible graphite under the condition of high temperature. The microstructure and composition was studied by using SEM and XRD. The study shows that the tubular structure of carbon nanotubes in the composite material is changed by high temperature expanding process, and the microstructure is different with different expanding temperature. When the expanding temperature was 900°C, carbon nanotubes transformed, then attached to the surface of expanded graphite flake, so carbon nanotubes and expanding graphite combined strongly; globular carbon nanotubes attached to the surface of expanded graphite flake at the temperature of 700°C, both were combined much more strongly; carbon nanotubes retained the tube structure at the temperature of 500°C, combination was looser due to the simple physical adsorption. The result shows that the choice of expanding temperature has an important effect on microstructure of carbon nanotube/expanded graphite composite material.


2013 ◽  
Vol 212 ◽  
pp. 247-254
Author(s):  
Marek Cieśla ◽  
Franciszek Binczyk ◽  
Marcin Mańka

mpact of complex modification and filtration during pouring into moulds on durability has been evaluated in this study in conditions of high-temperature creep of castings made from nickel superalloy IN-713C post production rejects. The conditions of initiation and propagation of cracks in the specimens were analysed with consideration of morphological properties of material macro-, micro-and substructure. It has been demonstrated that in conditions of high-temperature creep at temperature 980°C with stress σ =150 MPa creep resistance of the IN-713C superalloy increases significantly with the increase of macrograin size. Creep resistance of specimens made of coarse grain material was significantly higher than the resistance of fine grain material.


2003 ◽  
Vol 93 (10) ◽  
pp. 7118-7120 ◽  
Author(s):  
S. Liu ◽  
S. Bauser ◽  
Z. Turgut ◽  
J. Coate ◽  
R. T. Fingers

2001 ◽  
Vol 7 (S2) ◽  
pp. 544-545
Author(s):  
Philip J. Maziasz

Alloy development can range from purely empirical, trial-and-error efforts to very theoretical, based on either fundamental first-principles calculations or computational-modeling using various kinds of data base inputs. However, “real-world” efforts to improve or optimize complex engineering alloys often cannot afford the time or cost of either extreme approach. in the past 10-15 years, an alloy development and processing optimization methodology has been developed that utilizes strategic microanalytical data (both detailed microstucture and microcompositional information) as the critical input that then enables efficient and effective design of various kinds of alloys for improved high-temperature performance [1-6]. in many cases, first time tests produce outstanding high-temperature creep or creep-rupture results, and enable improvements without trading off one property for another. This invited paper will highlight several examples of significantly improved creep resistance obtained using such microstructural design.This microstructural design methodology for high-temperature creep-resistance was initially developed for and demonstrated in austenitic stainless steels (Fe-14Cr-16Ni) designed for improved creep-strength and rupture resistance at 700°C and above for superheater and boiler tubing in advanced fossil power plants.


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