Synthesis and formation mechanism of high‐purity Ti₃AlC₂ powders by microwave sintering

Abstract

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. K E Y W O R D Shigh purity, MAX phases, microwave, powders, synthesis How to cite this article: Chen W, Tang J, Shi X, Ye N, Yue Z, Lin X. Synthesis and formation mechanism of high-purity Ti 3 AlC 2 powders by microwave sintering. Int J Appl Ceram Technol. 2020;17:778-789. https ://doi.

Microwave‐Assisted Synthesis of Covalent Organic Frameworks: A Review

“…Better properties: materials with smaller particle size, narrow particle size distribution, high purity, and enhanced physicochemical properties have been reported [70] Higher yields due to minimization of side products [71–73] Other advantages: selective heating, easier scale‐up, lower power consumption (environmentally friendly), etc. …”

“…[70] -Higher yields due to minimization of side products. [71][72][73] -Other advantages: selective heating, easier scale-up, lower power consumption (environmentally friendly), etc. Considering all these outstanding features, it is not then surprising that they have been used in the synthesis of COFs.…”

Formation Mechanism of High-Purity Ti2AlN Powders under Microwave Sintering

“…Microwave sintering (MWS) is successfully used to prepare MAX-phase ceramics because of its numerous advantages, such as rapid sintering speed, uniform heating, and lower sintering temperature [ 25 , 26 , 27 ]; however, the microwave processing for Ti 2 AlN powders is rarely reported. Therefore, the present study was conducted to examine the possibility of Ti 2 AlN preparation through MWS.…”

Processing of MAX phases: From synthesis to applications

“…173,174 Starting precursors are heated under argon atmosphere with heating rates up to 200°C/min, maximum temperatures between 850°C and 1480°C, 170,173 and dwell times up to 30 minutes. 168,171 The reduction of the sintering temperature is associated with the enhanced diffusion of species by their interaction with the microwaves, and the reported decrease of the activation energy, 233 KJ/mol for the formation of Ti 3 SiC 2 . 174 The synthesized F I G U R E 7 A, Dense Cr 2 AlC samples with 100 and 45 mm diameter sintered by SPS, (B) scheme of SPS carbon bed approach to sinter complex shapes, and c) highly dense (98.2%) Ti 2 AlC gear wheel sintered using SPS carbon bed approach [Color figure can be viewed at wileyonlinelibrary.com] pellets exhibit high purity, with values up to 97.5%, 171 and grain size in the range between 1 and 10 µm.…”

“…168,171 The reduction of the sintering temperature is associated with the enhanced diffusion of species by their interaction with the microwaves, and the reported decrease of the activation energy, 233 KJ/mol for the formation of Ti 3 SiC 2 . 174 The synthesized F I G U R E 7 A, Dense Cr 2 AlC samples with 100 and 45 mm diameter sintered by SPS, (B) scheme of SPS carbon bed approach to sinter complex shapes, and c) highly dense (98.2%) Ti 2 AlC gear wheel sintered using SPS carbon bed approach [Color figure can be viewed at wileyonlinelibrary.com] pellets exhibit high purity, with values up to 97.5%, 171 and grain size in the range between 1 and 10 µm. 169,173 Synthesized pellets are typically porous, although relative densities up to 95% have been reported for Ti 3 SiC 2 doped with aluminum.…”