Carbon shape type and heat treatment effect on the structural characteristics of the carbide phase in the composite material Al-5%Cu-10%TiC obtained by the SHS method

The paper presents the analysis of carbon shape type effect (carbon black and multilayer carbon nanotubes) on the morphology and distribution of the titanium carbide phase in the composition of a composite material obtained by self-propagating high-temperature synthesis Al-5%Cu-10%TiC, further subjected to heat treatment as thermohardening and artificial ageing. It is shown that both carbon modifications make it possible to synthesize a highly dispersed carbide phase with dimensions up to 800 nm from its inception. However, during the subsequent heat treatment of samples obtained on the basis of a charge with nanotubes, a decrease in the dispersion of titanium carbide particles to 2 microns and an increase in their degree of agglomeration is observed, resulting in a decrease in the hardening effect of ageing. Based on the analysis of the mechanism of carbide formation, it is suggested that as a result of high-speed capillary spreading of titanium over the surface of carbon particles within synthesis, the formed particles inherit the geometry of the original carbon shape. In this regard, when using carbon black, the synthesis of rounded titanium carbide particles is advantageous, and in the case of nanotubes it is cylindrical particles that make the better of. Differences in morphology, in turn, determine the varying degree of self-diffusion during subsequent heating, which contributes to more significant changes in the dispersion and distribution of the carbide phase in samples synthesized on the basis of nanotubes. The obtained results lead to a conclusion that the type of carbon shape has a significant effect on the structural characteristics of the carbide phase and give reason to recommend the use of carbon black, which is characterized by a lower cost.