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Showing 1 to 13 of 13 for “"gamma prime"”.
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Transformation toughening of [gamma][prime]-strengthened metastable austenitic steels
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1990.
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Gamma prime precipitation modeling and strength responses in powder metallurgy superalloys
… including grain size and size distribution of gamma' precipitates. Heat treatment is the most critical processing step that has ultimate influences on the microstructure, and hence, on the mechanical properties of the materials. The main objective of this research was to study the gamma ' …
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Metallographic study of gamma - gamma prime structure in the Ni-based superalloy GTD111
… can be attributed to a large extent, to the gamma prime ([gamma]') precipitates found within the FCC [gamma]-matrix. Service-induced material degradation mainly involves coarsening and shape transformation of [gamma]'-phase precipitates; therefore, any bucket repair attempt should primarily …
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Microstructural responses of a nickel-base cast IN-738 superalloy to a variety of pre-weld heat-treatments
… primary carbide particles, and 42% primary $\gamma\prime$ particles respectively. The volume-fraction of primary $\gamma\prime$ particles decreased continuously from 20.1% to about 5% for solution-treatment temperatures (STT) in the range of 1120$\sp\circ$C-1225$\sp\circ$C. The solvus of …
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Atomistic modelling of precipitation in Ni-base superalloys
The presence 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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Non-destructive Electrical Characterization of Controlled Waspaloy Microstructures
… this research. In Set I microstructures, matrix (gamma) grain sizes of 13, 52 and 89 micrometers were obtained after solution-treatments at 1045 and 176;C, 1090 and 176;C and 1145 and 176;C respectively. A vacancy stabilization treatment at 1045 and 176;C followed after which, the specimens were …
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Investigation of lattice mismatch in rhenium containing nickel-base superalloys
In this study, three techniques for measuring gamma/gamma prime lattice mismatch were examined on two alloys, each of which had two different ageing heat treatments, i.e. standard age and overaged. Each alloy contained a different Re content so that the effect of this element on lattice mismatch …
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Stability of nickel-base superalloys for turbine disc applications
… are deleterious to alloy performance. High $\gamma^\prime$ volume fractions, which are needed to provide high-temperature strength, exacerbate the problem by increasing the concentration of these elements in the $\gamma$ phase. Therefore, an understanding of TCP formation and the compositional …
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Novel integrated computational approach for designing Fe-Ni-based alloys
… exposure due to finely dispersed precipitates, $\gamma^{\prime}$, although the strength is not as high as expected from the calculation. The microstructure analysis suggests that W in the designed alloy has a negative influence on the mechanical properties of the alloy by forming coarse Laves …
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Simulation of creep in nickel based single crystal superalloys
… solution and precipitation strengthening of the gamma ([gamma]) and gamma prime ([gamma]') phases, and the elimination of grain boundaries. Creep of Nickel based single crystal Superalloys are caused by two primary mechanisms, dislocation creep and diffusion creep. Several factors that affect the …
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Global fibrinolytic potential of black South Africans in the North West Province
… 4G/5G polymorphism and fibrinogen and fibrinogen gamma prime in determining CLT. Direct relationships with PAI-1act or CLT were not found for the C428T and G429A polymorphisms; they did, however, influence associations of other environmental factors with PAI-1act and CLT. Several of these …
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Phase Stability In Cobalt-Based L12 Quaternary Intermetallics From Density Functional Theory
The effects of higher order alloying additions (Mo, Ti, Ta, Hf, Fe, V) on the phase stability of L12 (γ’) intermetallics have been studied via first-principles. A 32 atom special-quasi-random structure was used to mimic the experimentally observed solid solution sublattice. Density of states …
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Enhancing hot tooling to forge high-γ ′ superalloys
High-γ ′ nickel superalloys are increasingly employed in aircraft turbines for their remarkable high-temperature properties to enhance engine efficiency and reduce aviation emissions. These alloys are forged at temperatures approaching 1100 °C and require careful selection of process parameters to …