Mechanical activation of self-propagating high temperature synthesis in titanium, carbon black and iron-based alloy powder mixtures

2019 ◽  
Author(s):  
A. V. Baranovskiy ◽  
G. A. Pribytkov ◽  
M. G. Krinitcyn ◽  
V. V. Homyakov ◽  
G. O. Dankovcev
2007 ◽  
Vol 336-338 ◽  
pp. 310-312
Author(s):  
Xiao Kui Liu ◽  
Wan Cheng Zhou ◽  
Fa Luo ◽  
Dong Mei Zhu

SiC-AlN solid solution powders were prepared from the mixtures of aluminum, silicon and carbon black in a nitrogen atmosphere with preheating self-propagating high temperature synthesis (SHS) method. The powders synthesized with different ratios of Al/Si were mixed with paraffin wax and the microwave permittivity of the mixtures was measured at the frequency of 8.2~12.4GHz. The results were contrasted with that of SiC powders synthesized by preheating SHS in argon and nitrogen atmosphere respectively. The ε′, ε″, and the tgδ (ε″/ε′) of the mixture of SiC prepared in a nitrogen atmosphere are highest, followed with those of the SiC-AlN solid solution powders and the SiC powders prepared in an argon atmosphere. Along with the increase of atomic ratio of Al/Si, the ε′, ε″, and tgδ of SiC-AlN solid solution decrease. We believe that, with the increase of AlN dissolved, the concentration of carriers and the effect of dielectric relaxation will decrease because of the two contrary dopants.


1999 ◽  
Vol 14 (4) ◽  
pp. 1516-1523 ◽  
Author(s):  
Yasuhiro Tanabe ◽  
Takashi Sakamoto ◽  
Nobuko Okada ◽  
Takashi Akatsu ◽  
Eiichi Yasuda ◽  
...  

Titanium carbide foams are synthesized by a self-propagation high-temperature synthesis technique using carbon black, which generates gases during the synthesis. The synthesis is performed under terrestrial and microgravity conditions. The effects of gravity on the synthesis are evaluated in this study. The foaming is mainly caused by H2O and CO gases from the carbon black. The elongation of the products increases with decreasing environmental pressure and increasing amount of generated gases. Since the gas flows out along the direction of the combustion wave propagation, the products expand only along this direction. The propagation velocity of the combustion wave increases with increasing amount of generated gases and environmental pressure, which is due to the amount of molten Ti transporting into the reaction/preheat zone. Under higher environmental pressures, thermal convection of the environmental gases mainly affects the propagation velocity. However, at lower pressures, the behavior of the molten Ti has a great effect compared with the gases surrounding the specimens.


2009 ◽  
Vol 144 ◽  
pp. 012080 ◽  
Author(s):  
T F Grigoryeva ◽  
Yu D Kaminsky ◽  
M R Sharafutdinov ◽  
T L Talako ◽  
I A Vorsina ◽  
...  

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