Modeling of Thermal Stresses in a Ti-Al-Fe Composite During Cooling After Heat Treatment

The article presents the results of modeling the effect of layer thicknesses in metallic (Ti-Al-Fe) and metal-intermetallic (Ti-TiAl3-Al-Fe2Al5-Fe) composites on the magnitude of thermal stresses arising at their interlayer boundaries after heat treatment. It is shown that cooling of a three-layer composite of steel 20880 + aluminum AD1 + titanium VT1-0 with an aluminum layer thickness of less than 0.3 mm after annealing at 640°C for 1 h, which ensures the formation of a diffusion zone at the steel-aluminum boundary consisting of two interlayers (FeAl3 and Fe2Al5) less than 50 μm thick, and at the aluminum-titanium boundary of the intermetallic compound TiAl3 with a thickness of 20 μm, leads to spontaneous separation of the aluminum layer from the steel as a result of the destruction of the intermetallic layer Fe2Al5, caused by the action of tensile stresses exceeding its yield strength.