The Effect of Coatings on the Oxidation Kinetics of Intermetallic Titanium Alloys of the Ti2AlNb and gamma-TiAl Systems

摘要

The results of a study of the effect of aluminide coatings of the NiCrAlY and Al(Si) systems on intermetallic heat-resistant titanium alloys VIT1 based on Ti2NbAl orthophase or TNM-B1 based on gamma-TiAl on the resistance to isothermal oxidation are presented. The structures, phase, and chemical composition of the coatings after annealing and after high-temperature oxidation at temperatures of 650 and 700 degrees C are considered. The coating layer of the Al(Si) system consisting of TiAl3, TiSi2 and Ti5Si3 sets a barrier for inhibiting diffusion of titanium into the coating layer of the NiCrAlY system, which is based on high-temperature phases of beta-NiAl and gamma'-Ni3Al, which provide heat resistance.