Influence of the chemical composition of the matrix on the structure and properties of monolithic SHS composites

OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 23 No. 3 2021 Fig. 3. Microstructure of SHS composites with a matrix of different chemical composition: a – Fe matrix; b – Fe + Ni; c – Fe + Ni + Cr; d – Cu a b c d separate clusters of boron carbide particles that did not have time to fully react according to the reaction (7). Probably, the following reaction took place: 2Ti + B 4 C → TiC + TiB 2 + 2B + Q. (9) Particles of B 4 C and boron were recorded based only on the results of SEM analysis on separate surface areas of the thin section of the composite system Cu-Ti-C-B (Fig. 6, Table 4). Nevertheless, the strength of this composite turned out to be the maximum of all the studied R bm 30 = 830 MPa (see table 2). Abrasion resistance of all explored SHS-composites turned out to be about the same (table 5). The relative wear resistance was calculated in comparison with indicators of the structural steel 40Cr samples, thus its’ ε = 1. Silicon carbide is harder (3,000-3,200 HV) in comparison to electro corundum (2,000-2,300 HV) [28], hence or all tested composites, the relative wear ε when tested with silicon carbide is higher. The coefficient of friction is at the level of 0.5 for all the studied composites. The minimum surface roughness is typical for a composite with a copper matrix.