Category: Superalloys

Nickel, Small Punch, Superalloys

Deformation mechanisms of IN713C nickel based superalloy during Small Punch Testing

The role of local microstructure is critical in materials performance and integrity in a cast alloy. The grain size and grain boundary distributions as well as local texture can create various microstructure/microtexture clusters that cause deformation localisation in the alloy. Inconel 713C nickel base superalloys are used as turbocharger turbine wheels for modern diesel engines, produced via investment casting. In such an alloy localised deformation … Continue reading Deformation mechanisms of IN713C nickel based superalloy during Small Punch Testing

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Nickel, Superalloys

The effect of strain distribution on microstructural developments during forging in a newly developed nickel base superalloy

In the current study, the effect of strain distribution in a simple forging geometry on the propensity for recrystallization, and its impact on mechanical properties has been investigated in a newly developed experimental nickel-based superalloy. The new alloy was produced via a Powder Metallurgy (PM) route and was subsequently Hot Isostatic Processed (HIP), isothermally forged, and heat treated to produce a coarse grain microstructure with … Continue reading The effect of strain distribution on microstructural developments during forging in a newly developed nickel base superalloy

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Environmental, Nickel, Superalloys

Localized microstructural characterization of a dissimilar metal electron beam weld joint from an aerospace component

Hydrogen induced cold cracking (HICC) and hydrogen embrittlement (HE) are influenced by the microstructural evolution, residual plastic strain (i.e. local misorientation), recrystallization of grains and the resultant grain boundary characteristic distribution (GBCD) brought about by welding processes. HICC and HE are known to cause failures in aerospace components and it is vitally important to quantify the microstructural evolution, degree of residual plastic strain and determine … Continue reading Localized microstructural characterization of a dissimilar metal electron beam weld joint from an aerospace component

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Creep, Nickel, Steel, Superalloys

The Potential United Kingdom Energy Gap and Creep Life Prediction Methodologies

The United Kingdom faces a looming energy gap with around 20 pct of its generating capacity due for closure in the next 10 to 15 years as a result of plant age and new European legislation on environmental protection and safety at work. A number of solutions exist for this problem including the use of new materials so that new plants can operate at higher temperatures, … Continue reading The Potential United Kingdom Energy Gap and Creep Life Prediction Methodologies

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Environmental, Fatigue, Nickel, Peening, Superalloys

Factors affecting the corrosion fatigue life in nickel based superalloys for disc applications

The nickel based superalloy 720Li is employed in the gas turbine due to its mechanical performance at elevated temperature. A comprehensive assessment of the materials behaviour under representative service conditions is reported to address the drive for ever increasing temperatures and more arduous environmental exposure. Fatigue experiments have been performed in an air and air/SOx environment at 700 ∘C containing a mixed salt as a contaminant. … Continue reading Factors affecting the corrosion fatigue life in nickel based superalloys for disc applications

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Fatigue, Nickel, Peening, Superalloys

Influence of shot peening on high-temperaturecorrosion and corrosion-fatigue of nickel basedsuperalloy 720Li

High-temperature corrosion fatigue, a combination of corrosion with a fatigue cycle, is an emerging generic issue affecting power generation and aero gas turbine engines and has the potential to limit component life. Historically, surface treatments, such as shot peening have been used to improve component life and have been optimised for fatigue response. Research into optimisation of shot peening techniques for hot corrosion and high-temperature … Continue reading Influence of shot peening on high-temperaturecorrosion and corrosion-fatigue of nickel basedsuperalloy 720Li

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Nickel, Superalloys

Microstructural evolution of a delta containing nickel-base superalloy during heat treatment and isothermal forging

The next generation of aerospace gas turbine engines need to operate at higher temperatures and stresses to improve their efficiency and reduce emissions. These operating conditions are beyond the capability of existing nickel-base superalloys, requiring the development of new high temperature materials. Controlling the microstructures of these new materials is key to obtaining the required properties and, therefore, it is critical to understand how these … Continue reading Microstructural evolution of a delta containing nickel-base superalloy during heat treatment and isothermal forging

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Nickel, Superalloys

Characterisation of an Advanced Nickel Based Superalloy Post Cold Work by Swaging

Cylindrical bars of the advanced nickel based superalloy RR1000 were subjected to swaging to induce approximately 30% cold work. Grain size analysis demonstrated a distinct modification to the microstructure whilst electron back scattered diffraction (EBSD) measurements confirmed the evolution of a relatively strong <111> texture parallel with the longitudinal bar axis. Intragranular strain damage was identified. The effects of the swaging on bulk mechanical properties … Continue reading Characterisation of an Advanced Nickel Based Superalloy Post Cold Work by Swaging

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Nickel, Superalloys

Microstructural Characterization of a Polycrystalline Nickel-Based Superalloy Processed via Tungsten-Intert-Gas-Shaped Metal Deposition

Recent trials have produced tungsten-inert-gas (TIG)-welded structures of a suitable scale to allow an evaluation of the technique as an economic and commercial process for the manufacture of complex aeroengine components. The employment of TIG welding is shown to have specific advantages over alternative techniques based on metal inert gas (MIG) systems. Investigations using the nickel-based superalloy 718 have shown that TIG induces a smaller … Continue reading Microstructural Characterization of a Polycrystalline Nickel-Based Superalloy Processed via Tungsten-Intert-Gas-Shaped Metal Deposition

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Fatigue, Nickel, Superalloys

The use of coupled nonlocal damage-plasticity to predict crack growth in ductile metal plates

A nonlocal coupled damage-plasticity model is presented for predicting crack growth within plates made from a ductile metallic alloy. The damage law is explicitly defined in terms of the accumulated nonlocal plastic strain ensuring efficient numerical implementation. On the basis of this model, a UMAT for the finite element (FE) package ABAQUS (implicit) is developed. Thin plates of different geometries were modelled and analysed using … Continue reading The use of coupled nonlocal damage-plasticity to predict crack growth in ductile metal plates

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