The Influence of Gas Atmosphere Composition on Formation of Surface Films in Self-propagating High-temperature Synthesis of Porous Ti3SiC2

Abstract

In the present work, the structure and composition of the surface layer formed during self-propagating high-temperature synthesis (SHS) of porous ternary carbide Ti 3 SiC 2 from the initial mixture of powders 3Ti+1.15Si+2C in the surrounding gas atmosphere of different compositions were investigated. Using X-ray analysis, scanning electron microscopy and energy dispersive analysis, it was shown that a porous composite material, consisting of the main phases Ti 3 SiC 2 and TiC, is synthesized under these conditions. During the synthesis in atmospheres of air and nitrogen, a film of 2-3 microns thickness consisting of TiO 2 and TiN is formed on the surface of the porous material. During the SHS process in an inert argon atmosphere and in vacuum, this film is not formed. In nitrogen atmosphere, conglomerates of TiN particles are formed on the film as well.

Influence of Heat Treatment on the Phase Composition and Microhardness of Coatings Based on Ti₃SiC₂/ TiC

“…Ensuring stable performance characteristics of products can be achieved both by creating new structural materials, including those with a modified structure, and by applying protective coatings on machine parts and tools [4,5]. At present, protective coatings based on transition metal carbides are widely used in industry [6,7]. These coatings have a unique combination of high hardness, corrosion resistance and wear resistance [8,9].…”

SHS process application in Ti3SiC2–Ni composite fabrication

“…Шихтовый брикет по варианту 1 или сборку из брикетов по вариантам 2 и 3 помещали в засыпку из просушенного речного песка на глубине 15-20 мм [23]. Зажигание шихтовых брикетов проводилось нихромовыми электрическими спиралями с помощью запальной смеси, представляющей собой ту же шихту СВС, но в насыпном виде.…”

“…На основании ранее проведенных исследований [23] известно, что пластины -это карбосилицид титана, а округлые частицы -карбид титана. Из рис.…”

“…МАХ-фазы получают разными способами, среди которых наиболее простым и наименее энергозатратным является СВС. Этим способом синтезированы МАХ-фазы в химических системах Ti-С-Al (карбоалюминиды Ti 2 AlC и Ti 3 AlC 2 ) и Ti-С-Si (карбосилицид Ti 3 SiС 2 ) [19][20][21][22][23]. Если сравнить прочность МАХ-фаз на изгиб, то самой прочной будет фаза Ti 3 SiС 2 (306-460 МПа), менее прочными -фазы Ti 3 AlC 2 (170-340 МПа) и Ti 2 AlC (275 МПа) [17].…”

Synthesis of MAX-Phase of Titanium Silicon Carbide (Ti₃SiC₂) as a Promising Electric Contact Material by SHS Pressing Method

“…In the first group, an expensive energy-consuming equipment is used, whereas in the second group, it is simple equipment with low energy consumption, so SHS methods are seen as more economical for the organization of industrial production of refractory materials and from this point of view, they are relevant for further improvement. In the work of authors [10], the use of the SHS without the application of excessive pressure to obtain porous titanium silicon carbide and the influence of the combustion gas atmosphere on the formation of surface films on porous material was considered. It is undoubtedly interesting to apply the method of the SHS with the application of excessive pressure (the method of SHS-pressing or SHS-compacton) to obtain dense Ti 3 SiC 2 and to investigate its properties, keeping in mind the prospects of its use as an electric contact material, that is the purpose of the present work.…”