On the chemical composition, structure and mechanical properties of alloy EP648 fabricated by deformation, project die casting and selective laser melting

Оспенникова, О. Г.; Min, P. G.; Rogalev, A.; Vadeev, V. E.

doi:10.22349/1994-6716-2020-101-1-44-54

Cited by 4 publications

(2 citation statements)

References 11 publications

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“…A regular γ-γ -microstructure with an optimal particle size of the γphase is formed in the case when AT objects are subjected to heat treatment after HIP. A large-scale quantitative study of the porosity in the Ni-based superalloy EP648 obtained by various methods-by means of deformation, investment casting, and selective laser melting-was carried out in [42]. The results of quantitative metallographic analysis of porosity in samples obtained by various methods are shown in Table 4.…”

Section: Defects and Properties Of Additive Objectsmentioning

confidence: 99%

Modern Powder Metallurgy: Chemical Composition Design for Improved Heat Resistant Alloys

Razumovskiǐ¹,

Logacheva²,

Razumovskiy

et al. 2021

Metals

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The modern approach to the design of heat-resistant metal alloys (HRAs) is analyzed, according to which the creep rupture characteristics of an alloy are mostly determined by the strength of interatomic bonding at grain boundaries (GBs) and in the bulk of a matrix phase. The main attention is paid to the concept of “low alloying additions” to polycrystalline alloys with transition metals, because of which the cohesive strength of the GBs and the cohesion energy of the alloy matrix are increased. This approach is especially important in relation to alloys obtained by powder metallurgy, which, in the compacted state, are fine-grained polycrystals. The methodology for calculating the key parameters of the theory (the energy of impurity segregation to the grain boundaries Egb and to the free surface Efs, as well as the values of the partial molar energy of the cohesion of the alloys) from the first principles is given. The results of applying the theory to the study of Ni-, Cr- and Ti-based alloys and the development of new HRAs based on them are presented. Typical defects in the microstructures of objects obtained using additive technologies (AT) and the application efficiency of standard methods of processing powder alloys (Hot Isostatic Pressing (HIP), heat treatment (HT)) to improve the microstructure and increase the mechanical properties are considered.

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Section: Defects and Properties Of Additive Objectsmentioning

confidence: 99%

Modern Powder Metallurgy: Chemical Composition Design for Improved Heat Resistant Alloys

Razumovskiǐ¹,

Logacheva²,

Razumovskiy

et al. 2021

Metals

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“…Such a positive effect of HIP is observed in the treating of many nickel HRAs [ 48 , 49 ]; Table 3 presents data for Ni-based superalloy EP741NP obtained by the SLM [ 49 ].…”

Section: Features Of the Microstructure Of Ni-based Superalloys Obtained Using Additive Technologiesmentioning

confidence: 99%

Cohesive Strength and Structural Stability of the Ni-Based Superalloys

Razumovskiǐ¹,

Bokstein

Logacheva³

et al. 2021

Materials

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The influence of alloying elements on the cohesive strength of metal heat-resistant alloys (HRAs) is analyzed. Special parameters are introduced to characterize the individual contribution of each alloying element. These are the partial molar cohesion energy of the matrix (χ) and the cohesive strength of the grain boundaries (η) and can be calculated by computer modeling based on the density functional theory. The calculating results of the parameters χ and η in nickel HRAs with mono– and polycrystalline structures alloyed with refractory metals are presented. The calculated data are used to select the chemical composition and develop new nickel (Ni) HRAs with superior creep-rupture properties. It is assumed that a similar approach can be used to search for alloying elements that will contribute to increasing the cohesive strength of additive objects. The resistance of coherent γ-γ’ and lamellar (raft) structures in nickel HRAs to the process of diffusion coarsening during operation is analyzed.

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