Effect of TiB2 Nanoparticles on Microstructure and Mechanical Properties of Heat-Resistant Alloy VZh159 Manufactured by Selective Laser Melting

Abstract

The effect of TiB₂ nanoparticles (0.5 – 2.0 wt.%) on the microstructure and mechanical properties of heat-resistant alloy VZh159 manufactured by selective laser melting is investigated. The microstructure is analyzed, the density of the samples is determined by hydrostatic weighing, and tensile tests are conducted. The addition TiB₂ refines the dendritic structure of the alloy from 8 – 12 to 2 – 3 μm and increases the microhardness to 349 HV, but reduces the ductility from 35.9% to 3 – 5%. Heat treatment enhances the embrittlement of the composites due to segregation of borides on grain boundaries. The transformation of TiB₂ into complex (Cr, Mo)B phases provides structure refinement but creates a brittle boride net.