Fabrication and Characterization of Ti/TiC Composite Layers by an Electron-Beam Surface Modification

In this study, the possibilities for modification and improvement of the surface structure and properties of titanium substrates by a formation of composite Ti/TiC layers are presented. The layers were fabricated by a two-step electron-beam surface modification technique. The first step consists of injection of C powder within the pure Ti substrates by electron-beam alloying technology. The second step is the refinement and homogenization of the microstructure by the electron-beam remelting procedure. During the remelting, the speed of the motion of the samples was varied, and two (most representative) velocities were chosen: 5 and 15 mm/s. Considering both speeds of the motion of the specimens, a composite structure in the form of fine TiC particles distributed within the base titanium matrix was formed. The remelting speed of 5 mm/s led to the formation of a much thicker composite layer, where the TiC particles were significantly more homogeneously distributed. The results obtained for the Vickers microhardness exhibit a significant increase in the value in the mentioned mechanical characteristic in comparison with the base Ti substrate. In the case of the lower speed of the motion of the specimen during the remelting procedure, the microhardness is 510 HV, or about 2.5 times higher than that of the titanium substrate. The application of a higher speed of the specimen motion leads to a decrease in the microhardness in comparison with the case of lower velocity. However, it is still much higher than that of the base Ti material. The mean microhardness of the sample obtained by the remelting speed of motion of 15 mm/s is 360 HV, or it is 1.8 times higher than that of the base material.

Automated summary

This study introduces the possibilities of modifying and improving the surface structure and properties of titanium substrates by creating composite Ti / TiC layers. These layers were fabricated using a two-step electron-beam surface modification technique. The first step involved injecting C powder into pure Ti substrates through electron-beam alloying technology. The second step involved refining and homogenizing the microstructure through electron-beam remelting. Different remelting speeds led to the formation of composite layers with varying distribution of TiC particles in the titanium matrix, resulting in increased microhardness compared to the base Ti substrate.