Low-cycle fatigue in Ni3Al-based alloys

Abstract

The low-cycle fatigue properties of hot-extruded powders of a Ni3AI-based alloy, IC 218, with nominal composition Ni-1 6.5AI-8.0Cr-0.4Zr-0.1B (at %) have been evaluated at room temperature. Tests were conducted under total strain conditions in a laboratory air environment. Results indicate that the low-cycle fatigue performance of the PM processed IC 218 nickel aluminide is superior to other structural alloys especially at higher strain amplitudes. These results are explained in terms of the high ductility of the fine-grain material and good crack growth propagation resistance in these alloys. Stress response curves for annealed IC 21 8 alloys indicate considerable cyclic hardening followed by cyclic softening. The onset of cyclic softening is found to occur at a constant cumulative plastic strain. The critical cumulative plastic strain criteria are verified for step-loaded IC 21 8 nickel aluminide coupons.

Study on Strain Rate–Dependent Deformation Mechanism of WC–10 wt% Ni3Al Cemented Carbide by Micropillar Compression

“…Typical stress–strain curves selected from the microcompression tests with different strain rates are shown in Figure a. As expected, the elastic modulus ( E ) of the composite is confined between the range of elastic modulus reported for Ni 3 Al (170–220 GPa) and WC (560–700 GPa) [3a]. A brittle stress–strain response is observed at higher strain rates (5 × 10 −2 and 1 × 10 −2 s −1 ), which is consistent with the previous analysis.…”

Effects of alloying elements on elastic properties of Ni3Al by first-principles calculations

“…The obtained elastic constant change rates (k) for different ternary elements can be used to predict the trends in the elastic properties of Ni 3 Al with respect to the composition of alloying elements. Gordon and Unni [59] performed the low-cycle fatigue tests at room temperature for a Ni 3 Al-based alloy, IC 218, with nominal composition Ni-16.5Al-8.0Cr-0.4Zr-0.1B (at.%) and reported Young's modulus of the alloy. The composition of the alloy used (20), it should be noticed that the alloy is not 100% g 0 -Ni 3 Al but a mixture of g 0 -Ni 3 Al and g-Ni at the annealing temperature of 1273 K [59].…”

“…Gordon and Unni [59] performed the low-cycle fatigue tests at room temperature for a Ni 3 Al-based alloy, IC 218, with nominal composition Ni-16.5Al-8.0Cr-0.4Zr-0.1B (at.%) and reported Young's modulus of the alloy. The composition of the alloy used (20), it should be noticed that the alloy is not 100% g 0 -Ni 3 Al but a mixture of g 0 -Ni 3 Al and g-Ni at the annealing temperature of 1273 K [59]. In order to obtain the relative amounts of the two phases, we use the nominal composition Ni-16.7Al-7.97Cr (at.%) and the thermodynamic database developed by Dupin et al [60].…”

Mechanical and Physical Properties of Ni₃Al-Based Alloys with Cr Carbides Dispersion

“…The stress increases from 300 MPa to 900 MPa by carbon addition. The strength of Alloy A is about half of the reported value for IC218 [12], due to the difference of grain size. On the other hand, the present results (Alloys A and B) are higher than those of Ni-19Al-4Cr(at.%) and Ni-19Al-4Cr-0.5C(at.%) alloys by Tian et al [7], respectively.…”