Synthesis of Ti₂SnC under Optimized Experimental Parameters of Pressureless Spark Plasma Sintering Assisted by Al Addition

Abstract

As an effective and novel rapid sintering technology with the advantages of fast heating speed and short sintering time, SPS has been applied to the research and development of various materials. After sintering at 1325°C, Ti5Sn3and Sn occurred as impurities accompanying the synthesis of Ti2SnC with a raw powder mixture of Ti/Sn/C = 2/1/1 (molar ratio). But by addition of 0.2 molar Al, and further optimization of sintering parameters at 1400°C for 10 min, almost fully pure Ti2SnC was obtained with a clear layered microstructure. The reaction mechanism analysis suggests that this beneficial effect of Al could be attributed to the suppression of decomposition of Ti2SnC by formation of Ti2SnxAl1−xC solid solution at a high sintering temperature. The present study reports a novel route to synthesize Ti2SnC by PL-SPS with a self-designed graphite die, and Al was also proposed as a sintering aid to remove impurities.

Vegard’s law deviating Ti 2(Sn x Al 1− x )C solid solution with enhanced properties

“…When elemental powders of Ti and C are used as starting materials, they first form TiC at an intermediate temperature, which acts as the crystallization nucleus for the subsequent formation of the MAX phase. However, the TiC impurities often remain in the final product due to incomplete consumption [31,38].…”

“…In particular, the Ti 2 SnC sample prepared herein is free of TiC and Ti-Sn impurities, much purer than those reported in Refs. [31,32], which was the first time to realize the synthesis of high-purity Ti 2 SnC. The diffraction peaks of the MAX phase solid solution monotonically shift to lower angles with the increasing x value, indicating that the Sn content in the Ti 2 (Sn x Al 1−x )C solid solution follows the expected composition trend.…”

The Key Role of Tin (Sn) in Microstructure and Mechanical Properties of Ti2SnC (M2AX) Thin Nanocrystalline Films and Powdered Polycrystalline Samples

“…The Ti 2 SnC is especially synthesized using a finely dispersed powder of the Ti, Sn, and C phases, mixed in stoichiometric ratios, grounded, pressed, and sintered at high temperatures [ 12 , 13 ]. Other techniques, such as spark plasma sintering [ 14 ], have been invented and used for Ti 2 SnC fabrication [ 15 ]. The applied methods, however, documented that together with the Ti 2 SnC composite, some precipitates (such as TiC, Ti 6 Sn 6, or Sn) are also detected.…”

Electric‐field assisted ultrafast synthesis of Ti3SiC2 MAX phase

“…Successful approaches were developed so far for the synthesis of MAX phases using different conventional techniques (Table 1). 15–43 Tabares et al. implemented pressure‐less sintering method to get 94% phase pure Ti 3 SiC 2 MAX powder at 1300°C for 6 h 17 .…”

“…As an effective and rapid sintering technology, Lu et al. synthesized Ti 2 SnC by spark plasma sintering with an addition of “Al” to remove impurities 20 . Most of the other researchers have synthesized fully dense (92%–94%) samples of Hf 2 SnC, Zr 2 SnC, Ti 2 SnC, Hf 2 PbC, Nb 2 SnC, Zr 2 PbC, and Ti 3 SiC 2 by hot‐isostatically pressing elemental powder mixtures in a temperature range of 1200–1500°C for up to 48 h 22,23 .…”