scholarly journals Al-Ti-B4C materials obtained by high-temperature synthesis and used as a master-alloy for aluminum

2018 ◽  
Vol 243 ◽  
pp. 00010 ◽  
Author(s):  
Ilya Zhukov ◽  
Vladimir Promakhov ◽  
Yana Dubkova ◽  
Alexey Matveev ◽  
Mansur Ziatdinov ◽  
...  

The paper presents microstructure, composition, and burning rate of Al alloy produced by high-temperature synthesis (SHS) from powder mixture Al-Ti-B4C with different concentration of Al powder. It has been established that the phase composition of materials obtained at gas-free combustion includes TiB2, Al, and TiC. It is shown that Al content growth powder in initial Al-Ti- B4C mixture from 7.5 to 40 wt.% reduces the burning rate of the powder from 9*10-3 to 1.8*10-3 m/s. For the system consisting of 60 wt.% of (Ti + B4C) and 40 wt.% of Al there is the increase in the porosity of the compacted initial powder mixture from 30 to 51 and reduction in the burning rate from 1.8 * 10-3 to 1 * 10-3 m/s. The introduction of 0.2 wt.% of the obtained SHS materials into the melt of pure aluminum causes reduction of the grain size of the resulting alloy from 1200 to 410 μm.

2019 ◽  
Vol 55 (11) ◽  
pp. 1097-1103
Author(s):  
V. Yu. Filimonov ◽  
M. V. Loginova ◽  
A. V. Sobachkin ◽  
S. G. Ivanov ◽  
A. A. Sitnikov ◽  
...  

2019 ◽  
Vol 26 (2) ◽  
pp. 422-429 ◽  
Author(s):  
Marina Loginova ◽  
Alexey Sobachkin ◽  
Alexander Sitnikov ◽  
Vladimir Yakovlev ◽  
Valeriy Filimonov ◽  
...  

An in situ synchrotron study of the specific features of the phase formation dynamics in mechanically activated 16 wt% Al + Ti powder composition is described, the high-temperature synthesis being carried out under the condition of high volume inflammation by means of inductive heating. The kinetics of the phase formation were registered with an experimental complex, especially designed, constructed and adjusted for the method of dynamic diffraction analysis in synchrotron radiation beams. It has been experimentally in situ shown that increasing the time of mechanical activation of the initial powder mixture reduces the temperature at which components start to react and the time of realization of the high-temperature synthesis. With the latter set at 1 min of mechanical activation, the temperature of the reaction in the mixture is T = 603°C; at 3 min of mechanical activation, T = 442°C; and at 7 min, T = 359°C. The maximum burning temperatures are: for 1 min of mechanical activation, T max = 1080°C; for 3 min, T max = 1003°C; and for 7 min, T max = 820°C. It was found that formation of both stable compounds Ti3Al, TiAl3, TiAl2, TiAl and metastable phases Ti9Al23, Ti5Al11, Ti2Al5, Ti3Al5 occurs at the stage of primary structure formation, before the system goes to thermal explosion. High-temperature synthesis of a mixture of the studied composition takes place without formation of a liquid phase, in the solid-phase combustion mode. It was found that the increase in the time of mechanical activation of the initial powder mixture contributes to the formation of a product with a dominant content of intermetallic compound Ti3Al. By synthesis of the powder mixture of composition 16 wt% Al + Ti, mechanically activated for 7 min, the content of Ti3Al in the final product was found to be 68%.


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 %.


HFI/NQI 2004 ◽  
2008 ◽  
pp. 738-744
Author(s):  
J. Fedotova ◽  
A. Ilyuschenko ◽  
T. Talako ◽  
A. Belyaev ◽  
A. Letsko ◽  
...  

2019 ◽  
Vol 25 (4) ◽  
pp. 744-751 ◽  
Author(s):  
Xiaomiao Niu ◽  
Hongyao Shen ◽  
Guanhua Xu ◽  
Linchu Zhang ◽  
Jianzhong Fu ◽  
...  

Purpose Mg-Al powder mixture was used to manufacture Mg-Al alloy by laser powder bed fusion (LPBF) process. This study aims to investigate the influence of initial Al content and processing parameters on the formability, microstructure and consequent mechanical properties of the laser powder bed fused (LPBFed) component. Design/methodology/approach In this study, Al powder with different weight ratio ranged from 3 to 9 per cent was mixed with pure Mg powder, and the powder mixture was processed using different LPBF parameters. Microstructure and compressive properties of the LPBFed components were examined. Findings It was found that the presence of Al significantly modified the microstructure and improved the mechanical properties of the LPBFed components. Higher volume of ß-Al12Mg17 precipitates was produced at higher initial Al content and higher laser energy density. For this reason, the a-Mg was significantly refined and the compressive strength was improved. The highest yield compressive strength achieved was 279 MPa when using Mg-9 Wt. % Al mixture. Originality/value This work demonstrates that LPBF of Mg-Al powder mixture was a viable way to additively manufacture Mg-Al alloy. Both Al content and processing parameters can be modified to control the microstructure and mechanical properties of the LPBFed components.


2013 ◽  
Vol 747-748 ◽  
pp. 124-131 ◽  
Author(s):  
Li Yuan Sheng ◽  
Jian Ting Guo ◽  
Chao Yuan ◽  
F. Yang ◽  
G.S. Li ◽  
...  

The Ni3Al and Ni3Al-B-Cr alloys were fabricated by the self-propagation high-temperature synthesis with hot extrusion method. Their microstructure and mechanical properties were studied by using combination of X-ray diffraction, optical microscopy, transmission electron microscopy and compression test. Analysis of X-ray spectra exhibited that the elemental powders had been transformed to the Ni3Al phase after the self-propagation high-temperature synthesis processing. Microstructure examination showed that the alloy without extrusion consisted of coarse and fine grains, but the subsequent hot extrusion procedure homogenized the grain size and densified the alloy obviously. Transmission electron microscopy observations on the Ni3Al alloy revealed that Ni3Al, γ-Ni and Al2O3 particles were the main phases. When the boron and chromium were added, besides the β-NiAl phase, α-Cr phase and some Cr7Ni3 particles with stacking faults inside were observed. In addition, a lot of substructure and high-density dislocation arrays were observed in the extruded part, which indicated that the subsequent extrusion had led to great deformation and partly recrystallizing in the alloy. Moreover, the subsequent extrusion procedure redistributed the Al2O3 particles and eliminated the γ-Ni. These changes were helpful to refine the microstructure and weaken the misorientation. The mechanical test showed that the self-propagation high-temperature synthesis with hot extrusion improved the mechanical properties of the Ni3Al alloy significantly. The addition of B and Cr in Ni3Al alloy increased the mechanical properties further, but the compressive strength of the alloy was still lower than that synthesized by combustion. Finally, the self-propagation high-temperature synthesis with hot extrusion was a good method to prepare Ni3Al alloy from powder.


2019 ◽  
Vol 26 (5) ◽  
pp. 1671-1678 ◽  
Author(s):  
Marina Loginova ◽  
Alexey Sobachkin ◽  
Alexander Sitnikov ◽  
Vladimir Yakovlev ◽  
Valeriy Filimonov ◽  
...  

In situ synchrotron studies of structure and phase formation dynamics in mechanically activated (t = 7 min, power density 40 g) and mechanically activated with subsequent irradiation by γ-quanta 60Co powder mixture (Ti 64 wt% + Al) during high-temperature synthesis by the method of thermal explosion using induction heating are described. In situ high-temperature synthesis was carried out on the created experimental complex adapted for synchrotron X-ray diffraction methods. The sequence of formation and time–temperature interval of the metastable and main phases were determined. The impact of preliminary mechanical activation and of γ-irradiation on the macrokinetic parameters of the synthesis were studied experimentally in situ. It has been established that the impact of γ-irradiation on the mechanically activated powder mixture of the composition Ti 64 wt% + Al leads to a change in the thermal parameters of combustion: the maximum synthesis temperature and the burning rate decrease. The heating rate for the non-irradiated mixture is 204.8 K s−1 and that for the irradiated mixture is 81.6 K s−1. The dependences of mass fractions of the synthesized compounds on time and temperature were calculated from the stage of preheating until completion of the thermal explosion. A single-phase equilibrium product of the composition γ-(TiAl) is formed in γ-irradiated mechanically activated mixture when the system reaches maximum temperature. The synthesized product of the mechanically activated mixture without γ-irradiation contains 72% γ-(TiAl); TiAl3 (26%) and residual Ti (2%) are also observed.


2010 ◽  
Vol 24 (15n16) ◽  
pp. 3203-3208
Author(s):  
LEI ZHAN ◽  
PING SHEN ◽  
QICHUAN JIANG

The effect of Al content on the self-propagating high-temperature synthesis (SHS) reaction among Al , TiO 2 and B 2 O 3 was experimentally investigated. The Al content plays an important role in controlling the reaction behaviors. With the increase in reactant Al , the maximum combustion temperature decreases, the propagating wave velocity first increases and then decreases, while the ignition delay time shows an opposite tendency. More importantly, the increase of the Al content in the reactants has an insignificant effect on the phase constitutions of the synthesized products but reduces the size of the synthesized TiB 2 particles.


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