Synergistic effect of microstructure and defects on the initiation of fatigue cracks in additively manufactured Inconel 718

Dodaran, M.; Muhammad, Muztahid; Shamsaei, Nima

doi:10.1016/j.ijfatigue.2022.107002

Cited by 25 publications

(6 citation statements)

References 81 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the T7‐475‐165 condition, the subsequent aging step below the Mg 2 Si solvus allowed the growth and formation of additional precipitates 58 . These precipitates, although were effective dislocation barriers under monotonic loading, could be sheared by the repetitive motion of dislocations in persistent slip bands leading to mechanical dissolution of precipitates over time under cyclic loading, which would possibly explain the softening response observed in the T7 condition 60 …”

Section: Discussionmentioning

confidence: 99%

Tensile and fatigue behaviors of additively manufactured AlSi10Mg: Effect of solutionizing and aging heat treatments

Baig

Ghiaasiaan

Shao

et al. 2023

Fatigue Fract Eng Mat Struct

Self Cite

View full text Add to dashboard Cite

The effects of various heat treatments on the microstructure and mechanical properties of laser beam powder bed fused AlSi10Mg were investigated. Specimens were solutionized at three different temperatures of 425 C, 475 C, and 525 C followed by natural aging (T4) prior to microstructural and mechanical characterization. In addition, the effect of aging was studied by artificially aging (i.e., T7) some of the solutionized specimens at 165 C. Solutionizing at all temperatures was observed to fully dissolve the additive manufacturing (AM) induced dendritic microstructure, leaving bulky Si and needle-shaped β-AlFeSi precipitates in the grain interiors and boundaries. Tensile results revealed that T4 specimens exhibited more ductility, while T7 specimens showed substantially higher strengths with slightly reduced ductility. Interestingly, no significant effect of heat treatment on strain-life fatigue behavior was observed. Fractography found the Si particles to be responsible for tensile fracture, while AM volumetric defects were the main initiators of fatigue cracks.aluminum, fatigue, laser beam powder bed fusion (LB-PBF/L-PBF), microstructure, tensile Highlights• Effect of heat treatments on tensile and fatigue behavior of L-PBF AlSi10Mg studied.• T7 treatment led to higher tensile strengths than T4, but similar fatigue lives.• Tensile failure initiated from Si-particle fracture or debonding from matrix.• Fatigue life was affected by the size of crack initiators, that is, volumetric defects. | INTRODUCTIONAluminum alloys are commonly used in various industries because of their superior strength/stiffness to weight ratio compared to other alloys. 1,2 Among various Al alloys, AlSi10Mg as a cast alloy 2 has historically been used to fabricate complex/thin-walled geometries. Recently, processing AlSi10Mg through additive manufacturing (AM) has shown to be very promising as intricate, lightweight parts can be manufactured without

show abstract

Section: Discussionmentioning

confidence: 99%

Tensile and fatigue behaviors of additively manufactured AlSi10Mg: Effect of solutionizing and aging heat treatments

Baig

Ghiaasiaan

Shao

et al. 2023

Fatigue Fract Eng Mat Struct

Self Cite

View full text Add to dashboard Cite

show abstract

“…[28] The formation of PSBs observed in ER tests with high mechanical strain amplitudes is typical for cyclically deformed Inconel 718 in conventional [29] as well as in additively manufactured form. [8,30] The presumable reason for the slight cyclic hardening observed in the ER test with ε a,me = 0.8% is the increase of dislocation density due to severe plastic deformation. It has to be noted that competing softening mechanisms, that is, precipitate shearing, dissolution, and coarsening, are also effective under ER loading (see Figure 7a,b).…”

Section: Microstructural Evolution and Cyclic Deformationmentioning

confidence: 99%

Creep–Fatigue Interaction of Inconel 718 Manufactured by Electron Beam Melting

et al. 2023

View full text Add to dashboard Cite

Electron beam melting of Ni‐base superalloy Inconel 718 allows producing a columnar‐grained microstructure with a pronounced texture, which offers exceptional resistance against high‐temperature loading with severe creep–fatigue interaction arising in components of aircraft jet engines. This study considers the deformation, damage, and lifetime behavior of electron‐beam‐melted Inconel 718 under in‐phase thermomechanical fatigue loading with varying amounts of creep–fatigue interaction. Strain‐controlled thermomechanical fatigue tests with equal‐ramp cycles, slow–fast cycles, and dwell time cycles are conducted in the temperature range from 300 to 650 °C. Results show that both dwell time and slow–fast cycles promote intergranular cracking, gradual tensile stress relaxation, as well as precipitate dissolution and coarsening giving rise to cyclic softening. The interplay of these mechanisms leads to increased lifetimes in both dwell time and slow–fast tests compared to equal ramp tests at higher strain amplitudes. Conversely, at lower mechanical strain amplitudes, the opposite is observed. A comparison with results of conventional Inconel 718 indicates that the electron‐beam‐melted material exhibits superior resistance against strain‐controlled loading at elevated temperatures such as thermomechanical fatigue.

show abstract

“…Moreover, the diverse patterns and paths of fine grain areas and crack propagation near the main crack initiated from microdefects 17 indicate that the interaction between defects and microstructure plays a crucial role in fatigue behavior. [18][19][20] Typical microstructures of dual-phase Ti-6Al-4V alloy are categorized as equiaxed structure, bimodal structure, and fully lamellar structure. 21 Bimodal Ti-6Al-4V alloy exhibits relatively more complex mechanical properties, resulting from the partially distributed lamellar structure.…”

Section: Introductionmentioning

confidence: 99%

Crystal plasticity modeling fatigue behavior in bimodal Ti–6Al–4V: Effects of microdefect and lamellar orientation

Zhao,

Tang,

Ferro

et al. 2024

Fatigue Fract Eng Mat Struct

View full text Add to dashboard Cite

Investigating fatigue failure in titanium alloys is crucial for material design and engineering. Fatigue behavior in dual‐phase titanium alloys is strongly correlated with microstructural features and microdefects. This work formulates an improved modeling method to investigate fatigue behavior of bimodal Ti–6Al–4V, emphasizing the effects of lamellar orientation and microdefects. Using an improved Voronoi tessellation method, we establish representative volume element (RVE) models with various grain size distributions. Crystal plasticity finite element modeling (CPFEM) is used to analyze fatigue deformation in bimodal Ti–6Al–4V, considering microdefects and lamellar orientation. Fatigue indicator parameters are then incorporated into CPFEM to predict fatigue life and verified with experimental data. Numerical results highlight the significant influence of lamellar orientation and microdefects on fatigue behavior, with predicted life within the 3‐error band. This method efficiently overcomes challenges in quantitatively characterizing microstructural lamellae that experiments are short of, paving the way for designing fatigue‐resistant alloy materials with similar microstructures.

show abstract

Synergistic effect of microstructure and defects on the initiation of fatigue cracks in additively manufactured Inconel 718

Cited by 25 publications

References 81 publications

Tensile and fatigue behaviors of additively manufactured AlSi10Mg: Effect of solutionizing and aging heat treatments

Tensile and fatigue behaviors of additively manufactured AlSi10Mg: Effect of solutionizing and aging heat treatments

Creep–Fatigue Interaction of Inconel 718 Manufactured by Electron Beam Melting

Crystal plasticity modeling fatigue behavior in bimodal Ti–6Al–4V: Effects of microdefect and lamellar orientation

Contact Info

Product

Resources

About