Explosively welded multilayer Ti-Al composites: Structure and transformation during heat treatment

Microstructural and Phase Composition Differences Across the Interfaces in Al/Ti/Al Explosively Welded Clads

“…Additionally, in the upper interface, TiAl 2 was observed (Figure 7(d)). There are other metastable phases that have been found in the literature, such as Ti 3 Al 5 and h-TiAl 2 , as shown by Lazurenko et al [25] and Palm et al [52] ; however, these were not observed in the current study. As presented in our previous work, [30] a small intensity of the analyzed reflections indicates a minor volume fraction of intermetallics in the sample.…”

“…This parameter was studied for multilayered Ti/Al clads in the works of Bataev et al, [24] Pavliukova et al, [33] and Lazurenko et al, [25] or for sandwiches of low-carbon steel setups in works of Bataev et al [46] In all these mentioned works, the examination was focused on the wavy mode of the interface, whereas the chemical composition was only analyzed in the vortex areas in the upper interfaces.…”

“…According to the present work, the location within the multilayered composites plays an important role, as different conditions of EXW occur on each interface. Hence, each interface should be considered separately, especially when many layers, for example, 6 [32] or 40, [25] are investigated. However, this fact was not clearly emphasized in the works of Foadian et al [32] and Lazurenko et al [25] These authors did not indicate which interfaces were taken into consideration for the kinetics calculations.…”

“…Another impressive example is the production of Al/Ti clads, which were successfully obtained with not only 2 [22] or 3 [23] layers, but 21 [24] or even 40 layers. [25] The EXW technique can also be used in the production of multilayered materials with significantly different properties, for example, metallic-intermetallic laminate composites. These composites belong to a new class of materials, whose properties combine the large ductility of the metal matrix and the high hardness of intermetallic phases.…”

“…Alternatively, further annealing causes the growth of a thermodynamically favored TiAl 3 intermetallic phase. [23,25,[30][31][32][33] The manufacturing of EXW clads requires a number of parameters to be controlled, such as the collision angle, impact velocity, detonation pressure, and geometry, with respect to the type of bonded materials. [28,[34][35][36][37][38][39] However, the problem becomes even more complicated when more than only one interface is obtained.…”