In this work, Ti 3 AlC 2 powders with high purity were prepared by microwave-assisted molten salt method (MA-MS). The synthesis parameters (such as raw materials ratio, heating temperature and reactant materials) and the formation mechanisms were systematically investigated. The results indicate that Ti 3 AlC 2 powders with a high purity up to 98.5% are prepared using TiH 2 /Al/1.8TiC mixture as reactant materials, and NaCl–KCl as molten salt by microwave-assisted heating at 1050 °C for 30 min. Compared with traditional heating methods, both the synthesis temperature and holding time of highly pure Ti 3 AlC 2 powders synthesized in this work are much milder. This high-efficiency synthesis approach could be ascribed to the synergistic effect of molten salt and microwave heating. Moreover, the TiH 2 –Al–TiC starting material is more suitable for the rapid synthesis of Ti 3 AlC 2 powders with high purity via present microwave-assisted molten salt method than that TiH 2 –Al–C.
Kai Su,Xuekun Tian,Xinmei Hou,Zhenyi Zhao,Xusheng Liu,Deze Ouyang,Huiyu Yuan,Xinhong Liu
Ti 3 AlC 2 powder was prepared via an efficient solid-liquid reaction in flowing argon using coconut shell charcoal as novel carbon source, and phase evolution, microstructure and oxidation behavior of Ti 3 AlC 2 powder were investigated. The results show that coconut shell charcoal is dominated by amorphous carbon after carbonization with some turbostratic graphite-like structure, and large specific surface area of coconut shell charcoal gives its excellent reactivity. Ti 3 AlC 2 powder prepared at 1400 °C for 1.5 h exhibits good crystallinity and typical nanolayered structure. Ti 3 AlC 2 powder remains thermally stable in air below 552 °C, while oxidizing occurs rapidly between 900 and 1100 °C. The isothermal oxidation curves show a parabolic-like, indicating that the oxidation process is primarily controlled by a diffusion mechanism. The good oxidation resistance of Ti 3 AlC 2 powder is attributed to the oxidized products of TiO 2 and Al 2 O 3 grains formed a connected and dense protective layer on the particle surface at elevated temperatures.
Weihua Chen,Jiancheng Tang,Xingwang Shi,Nan Ye,Zhihao Yue,Xinghao Lin
High-purity titanium aluminum carbide (Ti 3 AlC 2 ) powders were synthesized by a microwave sintering method using different titanium sources as raw materials. The prepared products were characterized by differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results indicated that the synthesized Ti 3 AlC 2 powders have high purity (97.5%) and even distribution of the grain size when using a 3TiH 2 /1.2Al/2C mixture as raw materials when the microwave sintering temperature and time were 1300°C and 30 minutes, respectively. The formation mechanism of the Ti 3 AlC 2 is described as proceeding via four stages. The solid-phase reaction between titanium and aluminum occurs below the melting point of aluminum and the main product is a Ti 3 Al phase, which is an observed intermediate compound for the formation of Ti 2 AlC and Ti 3 AlC 2 . Thus, this study provides a beneficial approach to low-temperature synthesis of high-purity Ti 3 AlC 2 materials.
Ti 3 AlC 2 , notable for its distinctive combination of metallic and ceramic properties, has attracted significant attention. The rapid synthesis of Ti 3 AlC 2 powders is crucial for mass production. In this study, Ti 3 AlC 2 powders with 85 wt% purity were synthesized efficiently using selective laser melting method, utilizing titanium powder, aluminum powder and titanium carbide particles as starting materials. This innovative method reduces synthesis time by a factor of approximately 30–240 compared to traditional heating techniques. Moreover, the apparent oxidation activation energy ( E ) and the pre-exponential factor of the synthesized Ti 3 AlC 2 were calculated as 53.86 kJ/mol and 12.74, respectively. Additionally, a powder composition containing 45 wt% Ti 3 AlC 2 exhibited a maximum reflection loss of −21.5 dB at 8.2 GHz with a thickness of 2.5 mm, achieving effective electromagnetic wave absorption in the frequency range of 7.4 GHz–9.4 GHz.
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