Formation of the Structure via Electron Beam Cladding of Coatings by Titanium Carbide-Titanium Binder Powders

摘要

The structural evolution of "titanium carbide-titanium binder" metal matrix composite powders is investigated during the electron beam cladding of coatings by means of X-ray diffraction, optical, and scanning electron microscopy methods. As established, the morphology and dispersion of carbide inclusions in the deposited coating differ from those in the initial particles. According to X-ray diffraction data, coarse equiaxial carbide particles are primary carbides of the composite powder, which exhibit no changes during the cladding process. Another part of the carbide phase in the coating is represented by dispersed particles with elongated shape. The results reveal partial dissolution of composite powder granules in the melt of the cladding bath during the cladding, followed by crystallization of the dispersed carbide phase in the form of dendrites from a liquid metal solution with titanium and carbon.