Effect of Diffusion Annealing Temperature on the Formation Process and Properties of a Carbon-Aluminum Composite Layer on Pure Titanium.

A carbon-aluminum composite layer was prepared on the surface of pure titanium by double glow plasma carburizing, magnetron sputtering aluminizing, and vacuum-diffusional annealing treatment. The microstructure, phase composition, and properties of the composite layer obtained at different annealing temperatures were investigated by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and the ball-on-disc wear method. Results showed that the layer contained a mixture of TiAl, TiAl, and TiC phases at 650 °C for 6 h, which can significantly enhance the hardness and wear resistance of pure titanium. The layer exhibited a higher hardness of around 1231 HV, a lower friction coefficient of 0.33, and lower wear volumes of 0.018 mm than those of the titanium substrate.