The Influence Of Hot Procedure And Parameters To Ti₃Al/TC4 Dual Alloy Compressor's Structure And Properties

Compressor disk is the very important rotational component on the aircraft engine. When the compressor disk is working, there are grads of greater temperature and stress between the rim and the center of the disk. In order to raise the thrust-weight ratio of the engine and to reduce oil consumption, the use of dual alloy disk has a promising prospect. Though Ti3Al based alloy has a good high temperature behavior, its room temperature plasticity is very low, and this results in shaping difficulty and high expensive of manufacturing. Relatively, TC4 is maturely applied to the compressor disk of the aircraft engine because of it's capability of working steadily for a long time below 450 ℃. The request of the temperature and stress can be satisfied if Ti3Al based alloy and (α + β ) two-phase alloy is connected into dual alloys by welding.This paper attempts to search the feasibility of the electron-beam weld of Ti3Al-based intermetallics and the TC4 (α + β )two-phase titanium alloy, and the influence of the hot deformation and heat treatments on the microstructure and properties at weldline.Ti3Al and TC4 welded by vacuum-electron-beam was forged by hot-die and was treated by different heat treatments process. Then the influence of different deformation and different heat treatments process on the microstructure and properties was studied.It has been investigated that the influence of forging temperature, heat treatment regime, deformation, interaction of heat and force on diffusion of elements Al, Nb, V at weld zone for Ti-24Al-15Nb-1.5Mo /TC4 dual alloy welded in vacuum with billet rolled or treated. The results showed it can add dynamic energy of nuclei to elevate forging or heat treatment temperature and it is favorable for developing diffusion rate of elements and making micro-hardness homogenization at weld seam. It is advantageous to refine grains and to vary shape and size of phases as increasing deformation too. The journey of diffusion can been shorted when grain is refined. It is high in niobium at Ti3Al side of weld seam.The results of the experiments show that the Ti3Al/TC4 dual alloy welded by electron beam in vacuum, forged by hot die and treated with 700℃/12h,AC has satisfied synthesis properties. And also it is a feasible way to manufacture dual alloy compressors.