ПОЛУЧЕНИЕ МАХ-ФАЗ В СИСТЕМЕ TI-AL-C МЕТОДОМ САМОРАСПРОСТРАНЯЮЩЕГОСЯ ВЫСОСКОТЕМПЕРАТУРНОГО СИНТЕЗА И ИССЛЕДОВАНИЕ ИХ СОСТАВА И МИКРОСТРУКТУРЫ

МЕТАЛЛУРГИЯ

Abstract

A typical representative of the MAX phases is Ti3AlC2. However, the currently existing methods of obtaining materials based on MAX-phases are far from being perfect. These metods are characterized by significant power consumption, complexity and multistage technological cycles, low productivity and do not always provide the required quality of materials according to structure and properties, as well as - purity. Based on the abovementioned it is required to create and develop new methods and technologies for their production. In this work, the synthesis of Ti3AlC2 from the Ti-Al-C powder mixture was carried out by the SHS method in the combustion regime. The effect of the amount of carbon on the phase formation process was studied. The XRD analysis showed that the product obtained is multiphase and consists, in  addition to the main phase, of the intermetallic phases Al3Ti, AlTi and Al5Ti2. It was found that at the aluminum content of 20 and 25%, all aluminum participates in the formation of the MAX phase, and the remaining titanium and carbon form a TiC compound. At 30% of the aluminum content, excess aluminum which does not participate in the formation of the MAX phase, forms an intermetallide Al3Ti with titanium. Thus, it is shown that Ti3AlC2, with a total MAX phase content of 94,9%, and TiC content not exceeding 5,1% can be obtained from the TiS-Al-C powder mixture by the SHS method. Micrographs show that with an increase in the amount of aluminum, the structure of the MAX phase becomes more porous. On the contrary, with an increase in the amount of titanium, the structure becomes more dense.