| As one of the Mn+1 AXn phase, Ti2SC combines the excellent performances of both metals and ceramics, while its self-lubrication is superior to graphite and MoS2 due to the layered structure. Consequently, Ti2SC becomes the focus of material researchers. But the former researchers pay more attention to using various testing methods on the characterization of Ti2SC bulk materials, which synthesized directly with Ti2SC powders. Thus, research on the synthesis of Ti2SC bulk materials with elementary substances was conducted in this paper.The emphasis of the research is on the preparation of Ti2SC bulk materials with elementary substances by hot-pressing sintering (HP) and spark plasma sintering(SPS). Due to the low boiling point and effumability of S powder, tow formulas of raw materials were adopted:①S powder directly mixed with other raw materials;②sing another compound including the S element mixed with other raw materials. Using apparatus such as X-ray diffraction system (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray spectrometer (EDS), X-Ray fluorescence spectrometer (XRF) and laser particle size analyzer (LPSA) to testing the products, and exploring the effects of different sintering processes and process parameters on the synthesized products. Finally, we characterized the physical properties of Ti2SC bulk materials synthesized in this research. The results indicated that:Mixed the Ti and S powder at the molar ratio=1:2 mixture evenly, and pressed the mixed powers into thin disks. Then sealed the disks in the vacuous quartz tubes, which heated to 650℃and maintained for 10 hours. Finally, we obtained yellow-green powders with an average diameter of 39.17μm. With the hexagonal layered microscopic structure, the chemical formula of the powders could be expressed as TiS2.01 corresponding to TiS2, which can then be applied to the synthesis of Ti2SC bulk materials.Ti2SC bulk materials included many TiC as the secondary phase can be fabricated by hot-pressing sintering with Ti, TiS2 and C powders. Appropriately increasing the sintering temperature and holding time can promote the reaction of raw materials; increasing the amount of TiS2 can alleviated the loss of S element. All these methods were beneficial to the synthesis of Ti2SC. Best result was achieved in vacuum with the pressure of 30MPa, when powder mixture of 3.0Ti/1.2TiS2/2.0C was hot pressed at 1600℃for 120 minutes.High-pure and fully dense Ti2SC bulk materials can be fabricated by SPS with 3.0Ti/1.2TiS2/2.0C powder mixture at 1450℃under vacuum and 30 MPa soaking for 10 minutes. The products had layered structure, of which the size reached 40μm. Appropriately increasing the sintering temperature and increasing the amount of TiS2 were favorable to the synthesis of Ti2SC. The sintering temperature of SPS was 150℃lower than that of HP, while the purity of the products by SPS was higher than HP. The fabrication of T12SC by SPS can be roughly divided into two phases:①Between 600℃to 1000℃, TiS2 resolve into TiS and S gas. Ti and C reacted and formed into TiC;②After 1000℃, TiS and TiC interacted into Ti2SC. Synthesized Ti2SC was unstably in high temperature. When sintering temperature was 1500℃, some Ti2SC decomposed into TiS and TiC, coupled with the volatilization of S gas.The measured density of the synthesized Ti2SC bulk material was 4.60g/cm3, which is 98.93% theoretical density of Ti2SC. Its Vickers microhardness Hv, flexural strength oy, compressive strengthσc and fracture toughness KIC were 6.7±0.3GPa, 394.0±12.0MPa,736.0±42.0MPa and 5.4±0.3MPa·m1/2, respectively. Mean thermal expansion coefficient of Ti2SC from 40℃to 1000℃was 8.40×10-6K-1. At room temperature, its heat capacity, thermal conductivity, resistivety, Seebeck coefficient and power coefficient were accordingly 0.56J/g-K,53.60 W/m·K,0.54μΩ·m,-12.70μV/K and 300.00μW/m·K. What's more, the heat capacity, thermal conductivity, resistivety, Seebeck coefficient and power coefficient were obviously increasing when temperature rose. The power factor was sharp decrease with a rise of temperature.
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