EFFECT OF THERMOMECHANICAL TREATMENT ON THE FORMATION OF THE STRUCTURE OF HIGH-STRENGTH Nb- AND Ti-BASED ALLOYS
The paper studies the effect of heat treatment conditions on the microstructure of the LN-1 (Nb-10W-5Mo-1.5Zr-0.15C) and TS6 (Ti-10.5Cr-7V-4Mo-3Al-1Zr) alloys. It is shown for the LN-1 alloy that, under specific temperature conditions, a sufficiently high level of plasticity, necessary for subsequent deformation, is realized in the alloy. The structural studies have revealed the formation of finely dispersed niobium-zirconium carbides in the matrix during thermomechanical strengthening with the use of preliminary annealing. It is demonstrated that cold deformation by drawing (ε = 24 %) of the TS6 alloy leads to the formation of a cellular-band structure with high dislocation density along the cell boundaries. In the process of subsequent aging, the β-phase disintegrates with heterogeneous isolation of thin α-phase plates thus ensuring a considerable increase in the strength characteristics of the alloy.