Structurization of Composites Based on Self-Fluxing Alloys with Titanium Diboride Additions

Abstract

The structurization and phase interaction during sintering of the Ni–Cr–B–Si–C–TiB₂ composite are studied. X-ray diffraction, scanning electron microscopy, electron microprobe analysis, and metallography are used to examine the effect of titanium diboride in the range 10–40 wt.% on the structural and phase composition of the material and powders for thermal spray coatings. It is established that titanium diboride additions lead the formation of new complex Cr(Ме)₂₃C(B)₆ phases with microhardness 18–19 GPa and ТіС. The size and number of these phases can be controlled by changing the amount and size of the additions and sintering conditions. The optimum amount of TiB₂ addition promoting high service properties is 20 wt.%. The new phases formed in the composite constitute 30 vol.% and their size is within 1 and 20 µm. It is possible to control the service properties of the Ni–Cr–B–Si–C–TiB₂ composites and thermal spray coatings by changing the structural and phase composition of the powder material.