Structurization of Composites from 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 10–40 wt.% titanium diboride additions on the structure and phase composition of the material and powders for thermal spray coatings. It is established that titanium diboride additions lead to the formation of new complex Cr(Me)23C(B)6 phases with microhardness 18–19 GPa and TiC phase. The size and content of these phases can be controlled by changing the amount and size of additions and sintering conditions. The optimum amount of TiB2 promoting high service properties is 20 wt.%. The new phases formed in the composite constitute 30 vol.% and their size is between 1 and 20 μm. It is possible to control the service properties of Ni–Cr–B–Si–C–TiB2 composites and thermal spray coatings by changing the structural and phase composition of the powder material.