Intermediate temperature creep of directionally solidified Ni-based superalloy containing local recrystallization

Influence of deformation temperature on recrystallization in a Ni-based single crystal superalloy

“…However, primary recrystallization (RX) may occur during heat treatment or long-term service, and degrade the creep and fatigue properties significantly [1,2]. RX is ascribed to plastic deformation during manufacturing and poses one of the major difficulties in post-casting processing of SX components.…”

“…One of the possible sources of the necessary plastic deformation before heat treatment is contraction stress during directional solidification, and the strains can be introduced at different temperatures [3,4] ranging from ambient temperature to elevated temperatures. However, most of the previous work on RX of SX superalloys focuses on the influence of annealing conditions [5], orientational dependence [6], microstructural features [7,8], and mechanical properties [2]. Little work has been conducted on the influence of deformation temperature on the RX of SX superalloys.…”

The deformation and the recrystallization initiation in the dendrite core and interdendritic regions of a directionally solidified nickel-based superalloy

“…Considerable work has been done on recrystallization (RX) due to its detrimental effect on the mechanical properties of directionally solidified (DS), especially single crystal (SX) superalloys [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. More attention has been paid to the effect of RX on the mechanical properties [1][2][3][4][5][6][7], the modeling of RX process [8], RX mechanisms [9][10][11][12][13] and the way to reduce or eliminate RX [14,15].…”

“…More attention has been paid to the effect of RX on the mechanical properties [1][2][3][4][5][6][7], the modeling of RX process [8], RX mechanisms [9][10][11][12][13] and the way to reduce or eliminate RX [14,15].…”

Evolution mechanism of recrystallization in a nickel-based single crystal superalloy under various cooling rates during heat treatment

“…It is well known that residual stresses generated during the removal of shell and cores can easily cause the formation of recrystallization layer on the surface of SX superalloy during heat treatment [2][3][4][5][6] . Due to the introduction of new grain boundaries (GBs) caused by the formation of recrystallization, the mechanical properties of SX superalloy are significantly decreased [7][8][9][10][11][12] . Jo et al [7] reported that the early initiation of surface cracks in recrystallized specimens at 982 °C and 240 MPa could reduce creep life.…”