Reaction behaviour, microstructure and mechanical properties of TiC–TiB2/Ni composite fabricated by pressure assisted self-propagating high-temperature synthesis in air and vacuum

2013 ◽  
Vol 49 ◽  
pp. 123-129 ◽  
Author(s):  
Y.F. Yang ◽  
Q.C. Jiang
2014 ◽  
Vol 900 ◽  
pp. 141-145 ◽  
Author(s):  
Can Feng Fang ◽  
Guang Xu Liu ◽  
Ling Gang Meng ◽  
Xing Guo Zhang

The effects of in-situ TiB2 particle fabricated from Al-Ti-B system via the self-propagating high-temperature synthesis (SHS) reaction technology on microstructure and mechanical properties of Mg-Sn-Zn-Al alloy were investigated. The results indicate that the size of the Mg2Sn and α-Mg+Mg32(Al,Zn)49 phase becomes coarser with the increasing content of Al-Ti-B preform, meanwhile the amount of eutectic α-Mg+Mg32(Al,Zn)49 phase increases too. The addition of Al-Ti-B is favorable toward promoting the strength of composites, but deteriorates elongation. The resulting as-extruded composite material with 4 wt.% Al-Ti-B preform exhibits good overall mechanical properties with an ultimate tensile strength of 291 MPa and an elongation over 2 %.


Author(s):  
D. H. A. Besisa ◽  
Z. I. Zaki ◽  
A. M. M. Amin ◽  
Y. M. Z. Ahmed ◽  
E. M. M. Ewais

In attempts to attain a SHS synthesized TiC‒Al2O3 composite with high density, homogenous microstructure and extra mechanical properties for using in aggressive media, addition of different reinforcements have to be studied and inspected. In this work, ductile nickel metal powder with different content (5‒20 wt. %) and 1 mole fraction dilution of alumina and zirconia with and without Ni addition are introduced to TiC‒Al2O3 ceramic and synthesized by combined self-propagating high temperature synthesis (SHS) and direct consolidation (DC) technique. The influence of nickel wt. % and dilution with zirconia and alumina on the phase composition, densification behavior, microstructure and mechanical properties of SHS synthesized TiC‒Al2O3 composite has been investigated and analyzed. Results revealed that, addition of 5 wt. % Ni gave the best densification behavior, microstructure and mechanical properties with exact formation of the target composite of TiC‒Al2O3. However, increasing Ni content higher than 5 wt % and dilution with zirconia and alumina led to disturbing the chemical reactions between the starting precursors, drooping and deterioration in density, microstructure and mechanical properties. Accordingly, this study suggests the addition of 5 wt. % Ni for a highly dense TiC‒Al2O3 composite with homogenized morphology and unparalleled mechanical properties. Moreover, the different investigated characteristics of the produced composites nominate it strongly to be used successfully in aggressive and tribological applications.


2013 ◽  
Vol 659 ◽  
pp. 10-14
Author(s):  
Yu Zhu ◽  
Feng Huang ◽  
Yu Xi Ge ◽  
Hong Jun Ni

In order to improve the density and mechanical properties of ceramic-lined composite steel pipes produced by Centrifugal Self-propagating High-temperature Synthesis. Composite steel pipes were prepared by the method of centrifugal-SHS on the basic of Al-Fe2O3 system. With the condition of adding 6% SiO2 and 4% Na2B4O7, the effect of different amount of nano-TiO2 on the density and the mechanical properties of composite steel pipes was studied. By means of SEM analysis, XRD and mechanical tests, the results show that the ceramic layer consists of main crystal phase of α-Al2O3, with small amount phases of FeAl2O4, Al2SiO5 and B2O3. The surface of ceramic layer is smooth, without obvious crack and with good density. The shearing strength of the ceramic layer and the crushing strength of the composite pipe were 13.5 MPa under 8% (in mass) nano-TiO2 and 525Mpa. The density of ceramic layer is up to 94.2% under 8% (in mass) nano-TiO2.


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