Nano-Ceramics Ti3SiC2 Max Phase Reinforced Single Walled Carbon Nanotubes by Spark Plasma Sintering

Badis Bendjemil
2015 Nanoscience & Technology Open Access  
Nanoscience & Technology: Open Access Open Access Research Article and containing small amounts (2 mol%) of TiC as a second phase, was a temperature of 1525°C maintained for 2 h as well as an applied pressure of 34.4 MPa. Dense samples synthesized in this study were examined by optical and electron microscopy. The maximum size in the elongated dimension of these grains is about 25 mm, which is smaller by a factor of four than the average grain size (100 mm) reported for samples produced by
more » ... g at 1600°C for 4 h [1]. Numerous papers on the synthesis and characterization of Ti 3 SiC 2 -based materials by means of the PDS technique were published by a Japanese research group [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] . Specifically, this ternary compound was first synthesized by reacting a Ti, SiC, and TiC powder mixture in the 4:2:1 molar ratio [2] . PDS process was conducted under vacuum at the temperature range of 1250-1450°C for 15-120 min with a heating rate of 50-60 8C/min and 50 MPa mechanical pressure. The purity and density of the obtained Ti 3 SiC 2 product were higher than 92 vol.% and 99%, respectively, when the sintering temperature was higher than 1350°C. At this latter value, the TiC content was almost constant in the sintering time interval of 15-120 min. Regarding samples microstructure, it was found to be of three types, that is, fine, coarse and duplex grains, depending on the sintering temperature and time. Besides the already investigated Ti/SiC/TiC reactants, another powdered mixture, that is, Ti/ TiSi 2 /TiC with 1:1:4 or 1:1:3 molar ratio was tested to synthesize the Ti 3 SiC 2 compound by PDS [3]. The process was carried out in a temperature range of 1100-1325°C for 0-60 min, 50-60°C/min heating rate and 50 MPa pressure. It was found that the formation of Ti 3 SiC 2 phase commenced at temperatures above 1200°C. The obtained products consisted of the desired compound along with TiC as a second phase. In particular, when the sintering was conducted at a temperature near 1300°C for 15 min, the maximum product Abstract Ceramics titanium silicon carbide Ti 3 SiC 2 Max phase was rapidly synthesised and simultaneously consolidated by spark plasma sintering at which the extensive volume expansion occurred as a function of the temperature from ball milled SiC/Ti/C powders with Ti/SiC ratio of 3:1:2. The XRD patterns results were confirmed by FESEM observations and the EDAX analyzes. The 3Ti+1.2SiC+0.8C nano-ceramics were processed from 3Ti+1.2SiC+0.8C/SWCNTs powders using Spark Plasma Sintering (SPS) at temperatures of 1100, 1200 and 1300°C with diting of SWCNTs from 0.0 to 1.0 wt% SWCNTs/Ti 3 SiC 2 nanocomposite. The effects of SWCNTs addition on phases, microstructure and hardness of the nanocomposite were investigated. The best product contained 1.0 wt% CNTs/ Ti 3 SiC 2 / TiC which was sintered at 1300°C, 60 MPa for 10 min The phase composition of the product could be tailored by adjusting the process parameters. The anisotropic hardness was observed in respect to the textured product.
doi:10.15226/2374-8141/2/2/00127 fatcat:oexovx2mkrdmjbs3b3qteuwa2m