SYNTHESIS OF MAX-PHASES OF THE TYPE Ti3AlC2 IN THE SHS PROCESS AND INVESTIGATION OF THE PHASE FORMATION PROCESS

Abstract

MAX phases exhibit an unusual and sometimes unique set of mechanical properties. This is, first of all, due to the nature of their special crystalline structure, as well as the mobility of dislocations of basic slip systems even at room temperature. The most studied representative of the MAX phases is the compound Ti3AlC2. Based on this compound obtained by the SHS method, the possibility of synthesis from a mixture of powders of Ti, Al and soot taken at different ratios of MAX–phases of the Ti3AlC2 type is studied. To ensure the maximum yield of the main component, the phase formation processes of the obtained product are studied. When a mixture of Ti, Al and soot powders is heated with a heating rate of 150 deg/min in the helium medium up to 755°C followed by cooling, the main product is the MAX phase Ti3AlC2 (90%). The results of a preliminary experiment huve shown that from a mixture of powders of titanium, aluminum and soot, a powder product can be obtained by the SHS method in which the maximum yield of the main MAX phase becomes Ti3AlC2 (99%). The microstructure of such a MAX material synthesized by powder metallurgy (SH synthesis) has a layered, laminate nature and can be a good raw material for further alloying of this compound with various metals for the development of powder metallurgy in Armenia. The phase and chemical analyses of the SHS products have shown the formation of transition zones of the variable composition at the boundary of the reacting compositions during the SH synthesis of MAX phases. The X-ray spectral analysis has confirmed the experimental results