Forming Mechanism of Flash in Linear Friction Welded Dissimilar Alloys of TC11 and Ti2AlNb

摘要

The macro and microstructures of the flash(upset metal)in linear friction welded TC11 and Ti2AlNb were observed. The flash was formed under action united friction press and shear force produced due to specimen motion. The expelled metal mainly was TC11 alloy and the axial shortening mainly happened in TC11 side. In the friction process, the interface temperature was above Ti2AlNb phase transformation point. From interface to inside of alloys, the grains size gradually became large due to the temperature effect in heat affected zone. Owing to the time limited,diffusion of alloying element was not enough resulting in large fluctuation on either side of the welding interface.