Creep Characteristic of NiAl-9Mo Eutectic Alloy

Abstract

The creep behavior of NiAl-9Mo eutectic alloy has been studied in an effort to understand the characteristic that the alloy exhibits of the low stress exponent of 4.75 and the high apparent activation energy of 410 kJ/mol during the steady-state creep of under the test conditions. The material exhibits threshold behavior with a threshold stress of 17.9 MPa. TEM observation reveals that the creep deformation is mainly governed by dislocation climb in NiAl matrix phase. Large recoverable strain is observed after unloading under the transient creep and increases with the increase of stress or temperature. It exhibits an activation energy 232 kJ/mol, suggesting the processes is controlled by the flow behavior of the matrix phase. The apparent creep activation energy under constant stress is a combination of the creep flow activation energy of the matrix and the activation energy for the damage process at the phase interface.

Mechanical properties of NiAl-Mo composites produced by specially controlled directional solidification

“…The creep resistance of well aligned NiAl-9Mo composites measured at 1273 K and 1373 K in the current study was compared with the ones of both single-and polycrystalline NiAl at 1300 K [9], irregularly aligned (or as-cast, microstructure similar to Figure 2a and b) NiAl-9Mo alloy at 1223 K [11], and single crystalline Ni-based superalloy NASAIR100 at 1300 K [12] in Figure 5. It is seen that the creep resistance of well aligned NiAl-9Mo has been remarkably improved compared to either the binary NiAl or the irregularly aligned NiAl-9Mo and is comparable to the Ni-based superalloy.…”

“…Comparison of creep strength of regularly aligned NiAl-9Mo in current study with the irregularly aligned NiAl-9Mo [11], binary NiAl [9] and a superalloy [13] at HT.…”

On the Nuances in the Power Law Description and Interpretation of High Homologous Temperature Creep and Superplasticity Data

“…From this, (𝐶𝐶 𝑖𝑖 / 𝐶𝐶 𝑖𝑖−1 ) should always be equal to (𝑝𝑝 0𝑖𝑖 𝑝𝑝 0(𝑖𝑖−1) ) × (𝜎𝜎 𝑐𝑐(𝑖𝑖−1) /𝜎𝜎 𝑐𝑐𝑖𝑖 ), where the subscripts (𝑖𝑖) and (𝑖𝑖 − 1) correspond to two different temperatures 𝑘𝑘 𝑖𝑖 and 𝑘𝑘 𝑖𝑖−1 . Copper [4] 141.2 148.2 NiAl [8] 169.5 169.2 Ni 3 Al (Zr, B) [9] 429.2 432.5 Ti-48Al-1Nb [10] 371.6 371.7 NiAl-9Mo [11] (new system) 341.6 Not previously reported Ti-H Alloy [12] (new system) 154.9 Not previously reported Defect and Diffusion Forum Vol. 385…”