Correlation the <112>{111} slip with high-temperature tension/compression asymmetry in the single-crystal nickel-based superalloy PWA1483

Figures & data

Figure 1. (a) Bright-field (BF) TEM image illustrating the γ/γ′ microstructure in PWA1483 after SHT; (b) HAADF image displaying the γ′ precipitates in PWA1483 after SHT; (c) typical engineering stress-strain curves of the [001]-orientated SC nickel-based superalloy PWA1483 in compression and tension at high temperatures; (d) tensile and compressive yield strength at 1000 and 1100 °C. With respect to the compressive stress-strain curves, the extensometer was not used during the tests. The crosses manifest that compression tests are broken off.

Figure 2. TEM images showing the typical microstructures in PWA1483 after around 2.0% compressive plastic strain at 1000 °C ((a)-(c)) and 1100 °C ((d)-(f)): (a) zig-zag and curve dislocations as well as isolated SSFs, g = $\left(\overline{2}00\right)$_BF; (b) isolated SSFs, pairs of a/2 < 110 > dislocations and a < 001 > superdislocations, g = (200)_BF; (c) MTs, DF image; (d) zig-zag and curve dislocations as well as pairs of a/2 < 110 > dislocations, g = (200)_BF; (e) isolated SSFs and a < 001 > superdislocations, g = $\left(\overline{2}00\right)$_BF; (f) MTs, DF image. The red arrowheads and blue triangles indicate the a < 001 > superdislocations and pairs of a/2 < 110 > dislocations, respectively. The while arrow indicates the spots of MTs within the diffraction pattern of the [011] zone axis.

Figure 3. TEM images showing the typical microstructures in PWA1483 after around 2.0% tensile plastic strain at 1000 °C ((a)-(c)) and 1100 °C ((d)-(f)): (a)zig-zag and curve dislocations as well as a < 001 > superdislocations, BF image, g = $\left(\overline{2}00\right)$_BF; (b) isolated SSFs, pairs of a/2 < 110 > dislocations and a < 001 > superdislocations, g = (020)_BF; (c) MTs, DF image; (d) zig-zag and curve dislocations, isolated SSFs and pairs of a/2 < 110 > dislocations, g = (200)_BF; (e) pairs of a/2 < 110 > dislocations and a < 001 > superdislocations, g = (200)_BF; (f) MTs, DF image. The red arrowheads and blue triangles indicate the a < 001 > superdislocations and pairs of a/2 < 110 > dislocations, respectively. The while arrow indicates the spots of MTs within the diffraction pattern of the [011] zone axis.

Figure 4. (a) HRTEM micrograph showing the formation of MTs in PWA1483 after around 2.0% compressive plastic strain at 1000 °C (Using the HRTEM filter script developed by Mitchell to filter the HRTEM image based on the work of Kilaas [45]); (b) CDF image showing one SSF, g = (020); (c) BF image illustrating the invisibility of the SSF with the reflection $\left(2\overline{2}0\right)$.

Kilaas R. Optimal and near-optimal filters in high-resolution electron microscopy. J Microsc. 1998;190(1-2): 45-51.

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