High-temperature forming, structure and phase composition of composites based on TiB/TiAl(Nb,Mo)B

The paper presents experimental studies of high-temperature molding of TiB/TiAl(Nb,Mo)B-based materials under free SHS compression conditions, which combines combustion processes in the mode of self-propagating high-temperature synthesis of the initial powder components and their shear deformation after the passage of the combustion wave. The objects of study were composites consisting of both 100 % TiB-(20 – 40) wt.% Ti and TiAl(Nb,Mo)B alloy (at %: 51.85 Ti – 43 Al – 4 Nb – 1 Mo – 0.15 B), and two-layer composite materials in the following layer proportions, vol. %: 70TiB/30 TiAl(Nb,Mo)B, 50TiB/50 TiAl(Nb,Mo)B, 30TiB/70 TiAl(Nb,Mo)B. The degree of deformation was chosen as the formability criterion for the studied composites during shear deformation. It was found that by changing the composition of each layer in the composite and the technological modes of free SHS compression, it is possible to regulate the degree of deformation from 0.2 to 0.55. It was shown that the technological modes of free SHS compression (delay time, pressing pressure, deformation rate) and the initial composition of the composites affect their formability and structure. The structural features of the obtained composites and their phase composition were studied. It was shown that a diffusion zone is formed between the ceramic and intermetallic layers as a result of chemical interaction, which can be regulated in the range of 30 – 150 μm.