The shape evolution of TiCx prepared by mechanical alloying of Ti-Al-C system after HF treatment
Introduction
Outstanding properties of the titanium carbide (TiC) such as high melting point, low density, superior hardness, high modulus, etc. have made it as an attractive material for various applications [1], [2], [3], [4], [5], [6], [7]. The physical and chemical properties of materials are influenced by their shapes. In literature, the different shapes have been reported for TiC particles, i.e. spherical, octahedron, cubic, hexagonal, cuboctahedron, etc. There are various intrinsic and external factors affecting the shape of the crystals. The equilibrium shape of crystals is caused by intrinsic factors while the external factors cause to form other non-equilibrium crystal shapes [5], [8], [9], [10], [11], [12], [13].
In literature, there are some papers regarding the shape evolution of TiC particles by various factors [14], [15], [16], [17], [18], [19], [20], [21], [22]. For example, Song et al. [19] successfully prepared the TiC particles via the self-propagating high-temperature synthesis (SHS) from the Ti-Al-C system. In their study, the effects of aluminum addition on the morphology of the obtained TiC particles was investigated. Their results showed that by increasing the amount of aluminum, the morphology of the TiC particles changed from near-spherical to cubo-ctahedron particles. Also, the size of TiC particles was decreased as a function of the amount of aluminum. However, the shape evolution mechanism of TiC was not studied by them. In another investigation, Zhang et al. [20] showed that by increasing the amount of Fe during the combustion synthesis of TiC in Ti-C-Fe system, the size of as-synthesized TiC particles decreased. Also, they reported that the morphology of the TiC particles changed to nearly spherical by increasing the content of Fe. The effect of carbon concentrations on the morphology of the TiC nanoparticles was investigated by Grove et al. [15]. They used the different concentrations of methane (CH4) as the reactant gas for synthesis of TiC nanoparticles by arc discharge method. Their results showed that, at low concentrations of CH4, the cubic shape of TiC nanoparticles was obtained. However, the cuboctahedron shape of TiC nanoparticles was achieved at high concentrations of CH4. They mentioned that the absorption of the C atoms on the (111) planes, retards the crystal growth on these planes which leads to the appearances of cuboctahedron shape of TiC nanoparticles.
In the above mentioned studies, the insight mechanisms for shape evolution of the TiC particles has not been reported. In literature, two valuable basic papers regarding the mechanisms for the shape evolution of TiC and other transition metal ceramics were published by Jin et al. [23], [24]. The former has focused on the shape evolution of the TiCx while the later has investigated the morphology evolution of various ceramics including ZrCx, NbCx, TaCx, TiNx, NbB2×, and TaB2× during the SHS. Their results demonstrated that the shape of the transition metal carbides (TMCs) is completely stoichiometry-dependent. They stated that for high quite stoichiometric TiCx, the shape is supposed to be cubic while for sub-stoichiometric TiCx the shape is octahedron. The changing in the stability of the (111) and (100) planes as a function of the stoichiometry of the TiCx was introduced as the main reason for the shape evolution event. The similar results were also reported by Zhou et al. [14].
In previous work, we studied the phase and morphological evolution of the Ti3SiC2 MAX phase powder by immersion in the hydrofluoric acid (HF) solution for different times [25]. The results indicated that after 24 h immersion of Ti3SiC2 into the HF solution, the Ti3SiC2 completely transformed to the TiC. Interestingly, SEM observations showed that by extending the immersion time, the TiC morphology was significantly changed from the polyhedron to hexagonal, then to truncated octahedron, octahedron and cubic. Our study was the first report for shape evolution of TiC particle via HF treatment. The purpose of the present study is to investigate the effect of HF treatment on the morphology of the TiC particles obtained by mechanical alloying of Ti-Al-C system.
Section snippets
Experiment
The elemental powders of Ti (99.7%, <1 µm), Al (99.7%, <200 µm) and graphite (99.7%, <200 µm) were used as raw materials. The powders were mixed according to the stoichiometry of Ti3AlC2, and were then ball milled with stainless steel containers and balls in Retch PM100 platenary ball mill. The ball to powder weight ratio was 10:1 and the rotation speed of containers was 450 rpm. The duration time of ball milling was 10 h. Then, 2 g of milled- powders were immersed in 50 mL of HF solution (49%)
Mechanical alloying of Ti, Al and, C powders
Fig. 1 shows the SEM images along with the XRD pattern of the MP sample. From the XRD pattern, it can be deduced that the mechanical alloying the Ti, Al and C powder mixtures has resulted in the formation of the TiC particles. As mentioned in the experimental section, the powders were mixed according to the stoichiometric composition of the Ti3AlC2. However, there is no sign of Ti3AlC2 phase in the XRD pattern of MP sample and same result has been observed by Sadeghi et al. [26]. They concluded
Conclusion
In this paper, the TiC particles were prepared by mechanical alloying of the Ti, Al and, C powder mixtures. The prepared powders were then immersed in HF solution for different times. XRD results showed that after HF treatment, no phase transformation occurred for TiC particles. However, after HF treatment the positions of the XRD peaks shifted toward the standard TiC peak position. This observation revealed the extraction of the Al element from TiC structure. In addition, by increasing the HF
References (32)
- et al.
Mechanochemical synthesis of nano TiC powder by mechanical milling of titanium and graphite powders
Powder Technol.
(2012) - et al.
In situ fabrication of TiC particulates locally reinforced aluminum matrix composites by self-propagating reaction during casting
Mater. Sci. Eng. A
(2008) - et al.
Preparation of titanium carbide nanowires for application in electromagnetic wave absorption
J. Alloy. Compd.
(2014) - et al.
Titanium carbide derived nanoporous carbon for energy-related applications
Carbon
(2006) - et al.
Formation of TiC hexagonal platelets and their growth mechanism
Powder Technol.
(2008) - et al.
Growth of TiC octahedron obtained by self-propagating reaction
J. Cryst. Growth
(2009) - et al.
Synthesis of titanium carbide nanowires
J. Cryst. Growth
(2000) - et al.
Influence of trace boron on the morphology of titanium carbide in an Al–Ti–C–B master alloy
J. Alloy. Compd.
(2010) - et al.
Study of formation behavior of TiC ceramic obtained by self-propagating high-temperature synthesis from Al–Ti–C elemental powders
Int. J. Refract. Met. Hard Mater.
(2009) - et al.
Study of formation behavior of TiC in the Fe–Ti–C system during combustion synthesis
Int. J. Refract. Met. Hard Mater.
(2011)
Phase and morphology evolution of TiC in the Ti–Si–C system
Int. J. Refract. Met. Hard Mater.
The phase and morphological evolution of Ti3SiC2 MAX phase powder after HF treatment
Ceram. Int.
Thermodynamic analysis of Ti–Al–C intermetallics formation by mechanical alloying
J. Alloy. Compd.
Effect of the starting materials on the reaction synthesis of Ti3SiC2
Ceram. Int.
A simple method of synthesis and surface purification of titanium carbide powder
Int. J. Refract. Met. Hard Mater.
Synthesis and morphological analysis of titanium carbide nanopowder
J. Am. Ceram. Soc.
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