Structural Effects of Cold-Sprayed Ti Coating Modified with Ti-Based Satellite Particles with In Situ-Formed TiC

Abstract

In this paper, the influence of Ti-TiC satellite powder obtained in situ by the CVD method on the microstructure, properties, and residual stress of titanium cold-sprayed coatings was studied. A commercially available titanium powder was subjected to a satelliting process using the CVD process, where TiC particles were in situ formed on titanium granules. Then, a powder mixture of pure Ti and 20 wt.% of Ti-TiC satellite powder was obtained. Cold spray coatings of Ti-(Ti-TiC)_sat powder mixtures were applied to Ti6Al4V substrates with carrier gas temperatures of 900 °C and 1100 °C. The coating characterization included microstructural analyses by SEM, hardness measurements, determination of Young’s modulus, phase composition by XRD, and residual stress measurements. Cross-sectional analysis revealed good cohesion between Ti and TiC during the satelliting process, which survives coating deposition. Moreover, the higher spraying temperature resulted in TiC crystallite size reduction, higher hardness, and Young’s modulus, decreasing linear and shear stresses.