A Study of the Structure and Properties of a Ti–Al–Mg/Ti-Based Metal–Intermetallic Material Produced by Self-Propagating High-Temperature Synthesis Combined with Pressing

Abstract

An metal–intermetallic material based on the combustion products of the layered system (Ti–Al–Mg)/Ti was first obtained using the self-propagating high-temperature synthesis (SHS) combined with pressing. Exothermic synthesis from elemental powders was carried out at a pressure of 10 MPa, and the hot product of synthesis was pressed at a pressure of 250 MPa. It was demonstrated that the SHS pressing process results in an inseparable bond between the “intermetallic/metal” layers. The main features of microstructure formation, phase composition, and strength properties of the transition zones at the interface between the reacting SHS compositions Ti–Al–Mg and the Ti substrate were investigated. The thickness of the transition zone between the layers was at least 15 μm. Energy-dispersive analysis (EDA) showed that Mg in the synthesized alloy is mainly located in intergranular layers, in the form of a small amount of Ti–Al–Mg compound, indicating incomplete reaction diffusion between the Ti–Al and Al–Mg layers. The microhardness of Ti–Al grains in the synthesized alloy is 5820 MPa on average, while that of the matrices based on Al–Mg is 3980 MPa. The hydrostatic density is 3.3 g/cm³, with a porosity of less than 13%. The porosity of the Ti–Al–Mg alloy obtained by the SHS pressing method was reduced by three times.