Microstructure and Compression Properties of VSS­V3B2 Eutectic Alloys in the V-Si-B System.

The present study reports on the microstructural evolution and room temperature plasticity of V(­Si)­B alloys with respect to the V solid solution (VSS)­V3B2 phase region. To investigate the occurring effects systematically, different binary V­B and ternary V­Si­B alloys were produced by conventional arc melting. Scanning electron microscope (SEM) analyses and X-ray diffraction (XRD) measurements were used to characterize the resulting as-cast microstructures. For the first time, the eutectic composition was systematically traced from the binary V­B domain to the ternary V­Si­B system. The observations discover that the binary eutectic trough (VSS­V3B2) seems to reach into the ternary system up to an alloy composition of V­5Si­9B. Room temperature compression tests were carried out in order to study the impact of single-phase and multi-phase microstructures on the strength and plasticity of binary and ternary alloys. The results indicate that the VSS phase controls the plastic deformability in the VSS­V3B2 eutectic microstructure whereas the intermetallic V3B2 acts as a strong hardening phase.