The residual stress generated in a superalloy during heat treatment affects the subsequent processing of workpiece and may even adversely affect its performance. This paper investigates effects pre-stretching (in range from 0% to 9%) before aging on quenching process microstructure Inconel 718 superalloy. After treatment, deriving can be well reduced. When pre-stretch level was 3%, reached maxi...

The realisation of employing Additive Layer Manufacturing (ALM) technologies to produce components in the aerospace industry is significantly increasing. This can be attributed to their ability to offer the near-net shape fabrication of fully dense components with a high potential for geometrical optimisation, all of which contribute to subsequent reductions in material wastage and component we...

The quality and economy of grinding depend on proper selection of grinding conditions for the materials to be ground. In order to evaluate the effect of heavy-duty grinding, a new performance index, which includes specific material removal rate, size accuracy, and grinding forces, was proposed. Robust design of experiment, including orthogonal arrays, the signal-to-noise ratio (SNR) method, and...

A microstructural study was conducted on 15 cobalt-chromium-nickel alloys of the basic composition 40 Co-30 Ni-30 Cr. The alloys were strengthened by the addition of tantalum and tantalum-rich regions were found at the interdendritic spaces. The increase in Ta concentration caused a decrease in the concentration of the a phase and an increase in the amounts of the a phase. Excessive amounts of ...

In this paper, the fatigue crack initiation in notched single-crystal test specimens of material MD2 is investigated and analysed. A critical plane approach is adopted, in which the total strain ranges on the discrete slip planes are evaluated. Furthermore, a Coffin-Manson type of expression is used to describe the number of cycles to fatigue crack initiation. This relation is determined from a...

Cyclic plasticity and creep are the primary design considerations of 1 and 2 stage gas turbine blades. Directionally-solidified (DS) Ni-base materials have been developed to provide (1) greater creep ductility and (2) lower minimum creep rate in solidification direction compared to other directions. Tracking the evolution of deformation in DS structures necessitates a constitutive model having ...

Grain size is an important parameter controlling the mechanical behavior and useful life of turbine disks. During heat treatment above the gamma prime (γ′) solvus the grain size increases dramatically as the γ′ particles dissolve. The grain size then stagnates as the volume fraction of the γ′ phase approaches zero. In general, the grain size at stagnation cannot be described by classic Zener pi...

Gaussian process regression machine learning with a physically-informed kernel is used to model the phase compositions of nickel-base superalloys. The delivers good predictions for laboratory and commercial superalloys, R2>0.8 all but two components each γ γ′ phases, R2=0.924 (RMSE=0.063) fraction. For four benchmark SX-series alloys methodology predicts composition RMSE=0.006 fraction RMSE=0.0...

The thermal barrier coating (TBC) of jet engine turbines permits operation at what otherwise would be prohibitively high temperatures. Ideally, a jet engine should operate at very high temperatures to maximize fuel efficiency and power. Combustion gases are often held at temperatures above 1370° C, while engine metal superalloys have melting points that range between 1230° and 1315° C. As a res...

In superalloys, topologically close–packed (TCP) phases, which contain refractory elements, usually significantly influence the mechanical properties. The current work investigates structure and composition of TCP phase in an Al–Mo–rich Ni–based single crystal superalloy. It is shown that after 40 h thermal exposure, a large number strip–like phases are formed, enriched Mo Re. identified as tet...