Effect of hot-deformation on the microstructure of the Ti–Al–Nb–W–B alloy

Effects of structural characteristics on microwave dielectric properties of Li2Mg(Ti1−xMnx)3O8 ceramics

“…2 (0≤x≤0.10) ceramics sintered at 1100°C for 4h shown in Fig.4. As we all know, the dielectric constant is dependent on the relative density, dielectric polarizabilities and structural characteristics such as the distortion, tilting and rattling spaces of oxygen octahedron in the unit cell [11][12]. In our experiments, ε r has no direct relationship with the relative density, which is because that the relative densities of all the specimens are higher than 95%.…”

Microstructure and tensile properties of hot fogred high Nb containing TiAl based alloy with initial near lamellar microstructure

“…This difference could be due to the high HIP temperature in αþγ phase field that improves the diffusion of β-stabilizing elements, namely, Nb and W. As shown in Fig. 1, the alloy contain more α 2 phases and thicker lamella spacing than that of traditional high Nb containing TiAl alloy, which reduces the blocking of interface to dislocation movement and is in favor of dynamic recrystallization (DRX) of coarsening γ laths [10,[17][18][19][20][21][22][23].…”

“…The yield stress is the highest when the loading axis is perpendicular to lamellar boundaries. In this direction, the α 2 phase is deformed in its hardest slip mode, and deformation must propagate through the lamellar interfaces, then this lamellar colony is in its hard orientation and will be remnant as RL structure [3][4][5][6][7][8][9][10][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. Thus, the α 2 phase significantly affects the RL structure.…”

“…Zhang reported that the dislocation density in fine γ laths is considerable lower than that in coarse laths, and the extent of deformation and recrystallization of relatively coarse γ laths is higher than that of fine γ lath [22]. Moreover, the stacking fault energy of α 2 phase is higher than that of γ phase [10,[10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]. At this point, the α phase tends to undergo dynamic recovery (DRV) during deformation in the αþγ phase field, whereas DRX is the main deformation mechanism of the γ phase.…”

Characteristics of the Dynamic Recrystallization Behavior of Ti-45Al-8.5Nb-0.2W-0.2B-0.3Y Alloy during High Temperature Deformation

“…It is also well-known that hot deformation is an effective method to optimize the microstructure, to further improve these properties. Dynamic recovery, phase transformations and DRX will occur during deformation at high temperature, resulting in the variation of size, morphology, fraction and distribution of phases [4,[10][11][12][13][14]. Moreover, microstructure evolution is affected by hot deformation parameters, especially by deformation temperature, strain rate and degree of deformation [15,16].…”