Ignition mechanism in combustion synthesis of Ti–Al and Ti–Ni systems

Bertolino, N.; Monagheddu, M.; Tacca, Alessandra; Giuliani, P.; Zanotti, C.; Tamburini, Umberto Anselmi

doi:10.1016/s0966-9795(02)00128-0

Cited by 90 publications

(43 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The combination of these properties makes these compounds suitable for advanced applications in the aerospace and automotive industries as well as in energy generation [1,2]. Although there are several processing methods for producing intermetallic compounds [3], combustion synthesis or reactive sintering has drawn special attention due to its technical and practical advantages such as relatively low cost, faster production and simplicity [4][5][6][7][8][9][10][11][12][13]. In a process based on combustion synthesis, the reactant powders are typically mixed and pressed into green compacts and are subsequently heated to synthesize the desired intermetallic compound.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Reactive synthesis and characterization of titanium aluminides produced from elemental powder mixtures

Sina

Iyengar

2015

J Therm Anal Calorim

View full text Add to dashboard Cite

The formation of titanium aluminides in Ti-Al elemental powder mixtures containing 25, 50 and 75 at.% Al, has been studied using differential scanning calorimetry (DSC). Phase evolution in the mixture was followed by heating the compacted samples up to 1273 K at 7.5 and 15 K min -1 . The cooled samples were characterized using X-ray diffraction, scanning electron microscopy and energy-dispersive spectroscopy. The results showed that the primary combustion product in all the samples was TiAl 3 , and the combustion reaction occurred below the melting point of aluminum only in Ti-rich samples. In Alrich samples (75 at.% Al), TiAl 3 was obtained as a porous, single-phase product after combustion. In samples containing 25 and 50 at.% Al, the combustion reaction was incomplete and the unreacted titanium particles were covered by a layer of TiAl 3 . In these samples, other intermetallic compounds such as TiAl 2 , TiAl and Ti 3 Al were observed to form upon heating beyond the combustion peak and are attributed to the solid-state reaction between unreacted titanium and TiAl 3 . Heating the samples with 25 at.% Al to 1273 K for an hour led to the formation of a homogenous Ti 3 Al product, while a multiphase product with a dominant TiAl phase was observed in samples containing 50 at.% Al. Calculations based on DSC data show that the formation of TiAl 3 through the reaction between solid titanium and molten aluminum is associated with an apparent activation energy of 195 ± 20 kJ mol -1 and an enthalpy of -114 ± 5 kJ mol -1 .

show abstract

Section: Introductionmentioning

confidence: 99%

“…Bertolino et al [8] studied reactive sintering in Ti-Al powder mixtures with different initial compositions and heating rates. Based on the temperature profiles obtained, they reported the initiation of combustion at 918 ± 10 K. The reaction was observed to proceed in the explosion mode after the aluminum had melted completely.…”

Section: Introductionmentioning

confidence: 99%

Reactive synthesis and characterization of titanium aluminides produced from elemental powder mixtures

Sina

Iyengar

2015

J Therm Anal Calorim

View full text Add to dashboard Cite

show abstract

“…Self-propagating high-temperature synthesis (SHS) is a well-known technique used to prepare a variety of materials including carbides, borides, nitrides, intermetallics and composites [1][2] . The SHS has unique advantages such as simple process, shorter reaction time, saving energy, more pure synthesized products and so on [3][4][5][6] .…”

Section: Introductionmentioning

confidence: 99%

Microstructural evolution during self-propagating high-temperature synthesis of Ti-Al system

Fan

Zhang

et al. 2008

J. Wuhan Univ. Technol.-Mat. Sci. Edit.

View full text Add to dashboard Cite

In order to investigate the microstructural evolution during self-propagating high-temperature synthesis (SHS) of Ti-Al powder mixture with an atomic ratio of Ti: Al=1:1, a combustion front quenching method (CFQM) was used for extinguishing the propagating combustion wave, and the microstructures on the quenched sample were observed with scanning electron microscope (SEM) and analyzed with energy dispersive spectrometry (EDS). In addition, the combustion temperature of the reaction was measured, and the phase constituent of the synthesized product was inspected by X-ray diffraction (XRD). The results showed that the combustion reaction started from melting of the Al particles, and the melting resulted in dissolving of the Ti particles and forming of Al 3 Ti grains. As the Al liquid was depleted, the combustion reaction proceeded through solid-state diffusion between the solid Al 3 Ti and the solid Ti. This led to the forming of TiAl and Ti 3 Al diffusing layers. In addition, the combustion reaction is incomplete besides TiAl, there are a large amount of Ti 3 Al and TiAl 3 and a small amount of Ti in the fi nal product. This incompleteness chiefl y results from the using of coarser Ti powder.

show abstract

“…In the first case, a laser can be used as an external energy source (Bertolino et al, 2003). As for explosive sintering, the reaction takes place after explosion during the temperature rise.…”

Section: Preparation Of Alloys Using Powder Metallurgymentioning

confidence: 99%