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Showing 1 to 20 of 20 for “"Ni-base"”.
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Hierarchical multiscale modeling of Ni-base superalloys
Ni-base superalloys are widely used in hot sections of gas turbine engines due to the high resistance to fatigue and creep at elevated temperatures. Due to the demands for improved performance and efficiency in applications of the superalloys, new and improved higher temperature alloy systems are …
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Atomistic modelling of precipitation in Ni-base superalloys
… of the ordered $\gamma^{\prime}$ phase ($\text{Ni}_{3}\text{Al}$) in Ni-base superalloys is fundamental to the performance of engineering components such as turbine disks and blades which operate at high temperatures and loads. Hence for these alloys it is important to optimize their …
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Investigation of Weldability in High-Cr Ni-base Filler Metals
High-Cr Ni-base alloys have been used in the nuclear industry for weld overlay repair of dissimilar metal welds which have been affected by primary water stress corrosion cracking. During welding, defects may result from super-solidus and sub-solidus cracking phenomena. The ability to evaluate and …
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Deformation at Low Temperatures in Single Crystal Ni-base Superalloys
The development of single crystal Ni-base superalloys for gas turbine applications has focused on creep behaviour in the high-temperature regime (above 700 °C). However, the study of deformation in the range of 20 °C to 700 °C is critical to understanding behaviour in the shanks of turbine blades …
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Data-driven Process-Structure-Property Models for Additive Manufactured Ni-base Superalloys
… and sources for the creation of a coherent database. Secondly, this work seeks to investigate the implementation of various statistical and Machine Learning (ML) approaches for the establishment of the PSP models. Both parametric and non-parametric regression techniques are employed to construct …
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Development of new high entropy alloys for brazing of Ni-base superalloys
… component alloys, are novel alloys containing at least five elements with an atomic percent ranging between 5% and 35%. HEAs have attracted attention due to their unique properties such as high strength, good ductility, and high resistance to corrosion and wear. However, applications of …
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Irradiation-induced nanoclusters and their evolution in compound forming ni-base and cu-base alloys
… precipitates are actively studied for designing materials tolerant to irradiation at high temperatures. The challenge is that nanostructures will often coarsen under elevated temperature irradiation or annealing, owing in part to radiation-enhanced diffusion. In this thesis, we propose a …
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A Study of the Effects of Laser Shock Peening on Residual Stress, Microstructure and Local Properties of IN718 Ni-Base Superalloy
<p>In this project effects of Laser shock peening (LSP) on two aero engine alloys, IN718 and IN718 SPF were studied. The primary goal of the program was to secure required fundamental knowledge of e impact of LSP process parameters on these two aero engine alloys and thereby advance the science and …
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Elemental Effects of Fe, Mo, C, and Hf (or Nb) on Solidification Behavior, Microstructure, and Weldability of High-Cr, Ni-base Filler Metals
… stress corrosion and ductility-dip cracking in Ni-Cr-Fe base materials and filler metals has led to increased Cr, Nb, and Mo contents in these alloys, respectively. Nb additions however, have resulted in a significant increase in the solidification cracking susceptibility of Ni-Cr-Fe-Nb filler …
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Development of Low-Cost Polycrystalline Nickel-Base Superalloys for Gas Turbine Applications
Polycrystalline nickel-base superalloys have found extensive application throughout the aerospace, petrochemical and power generation sectors, due to their exceptional balance of high temperature mechanical properties, thermal stability and oxidation resistance. Extensive alloy development has …
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Chemical and structural analysis of grain boundaries in Inconel 690 for corrosion resistance
Stress Corrosion Cracking (SCC) is a failure mechanism that results from the combination of tensile stress, corrosive environment and material susceptibility; it is frequently an intergranular attack. Material-environment combinations for SCC readily exist in nuclear power plants, and are critical …
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Development of the Strain-To-Fracture Test to Study Ductility-Dip Cracking in Austenitic Alloys
… test has been developed as a robust testing technique for ductility-dip cracking (DDC) and other elevated temperature cracking phenomenon. Samples are tested over a range of temperature and strain, producing temperature-strain cracking envelopes. Threshold strain for fracture (Emin) and the …
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Interdiffusion Analysis For Nicocraly And Nial Vs. Various Superalloys
Hot section components in gas turbines can be NiCoCrAlY-coated to provide the component with an Al reservoir that maintains a protective oxide layer on its surface. Over the service life of the component, the coatings degrade by composition and phase changes due to oxidation/hot-corrosion, and …
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Solid sample introduction in inductively coupled plasma emission spectrometry.
… of these uses the direct insertion probe technique first described by Horlick and Salin (63). The assembly utilised an electrically operated graphite rod system. This could be used equally well with small volumes of solution sample (5ul) or small masses of solid sample (Ca.5mg). The variables …
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Materials Design for Advanced Nuclear Energy Systems: Refractory High Entropy Alloys and Metallic Multilayer Composites
… this thesis, I focus on two approaches to designing better materials for advanced reactors, high entropy alloys (HEAs) and metallic multilayer composites (MMLCs). HEAs are chemically disordered solid solutions combining 4-5 or more elements, which of- ten have superior mechanical properties and …
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Hydrogen embrittlement testing of alloy 718 for oil and gas applications
Hydrogen embrittlement of Ni-base corrosion resistant alloys (CRAs) can occur in deep sea oil wells when components are exposed to hydrogen while under stress. The effects of microstructure on hydrogen embrittlement of precipitation hardened Ni-base CRAs, such as alloy 718, are not fully …
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Deformation mechanisms in a polycrystalline Ni-based superalloy
… window extends into a new deformation mechanism regime that needs to be explored and understood to be able to design and optimise new and existing Ni-based disc superalloys. For this purpose, this work investigates the deformation behaviour of the established coarse-grained RR1000 alloy …