http://tim.sagepub.com/content/33/6/718 The online version of this article can be found at: DOI: 10.1177/0142331209342211 February 201

A program has been conducted on the effects of Mg in cast alloy 718. The results show that small amounts of Mg improves impact toughness and decreases Nb segregation by decreasing secondary dendrite arm spacing which results in less and smaller interdendritic Laves and MC eutectics. Small amounts of Mg produce a more spheroidal as well as a more dispersive MC phase. Impact toughness was found t...

In this study, residual stresses from the electron beam additive manufacturing (EBAM) and selective laser melting (SLM) processes, due to repeated thermal cycles, were investigated. Residual stresses play a crucial role in part performance, and thus, it is critical to evaluate the process-induced residual stresses in AM parts. Ti-6Al-4V and Inconel 718 parts produced by EBAM and SLM, respective...

Titanium alloy Ti–6Al–4V and nickel-based superalloy Inconel 718 have been widely employed in modern manufacturing. The published literature on high speed machining (HSM) of the two materials often involves different machining set-up, which makes it difficult to directly apply the research findings from onematerial to the other to select the most appropriate tool geometry and cutting conditions...

The objective of this investigation was to develop an innovative methodology for life and reliability prediction of hot-section components in advanced turbopropulsion systems. A set of generic microstructure-based time-dependent crack growth (TDCG) models was developed and used to assess the sources of material variability due to microstructure and material parameters such as grain size, activa...

Companion laboratory-scale studies were conducted on specimens of ESR alloy 718 in order to determine responsiveness of this material to several of the macroetching techniques used in the industry. The work developed from initial efforts to define the relative sensitivity to Alloy 718 segregation of the macroetchants in standard use at the respective locations of Into Alloys International: one ...

We present a study of the ability of the Fermi Gamma-ray Space Telescope to detect dark matter (DM) annihilation signals from the Galactic subhalos predicted by the Via Lactea II N-body simulation. We implement an improved formalism for estimating the boost factor needed to account for the effect of DM clumping on scales below the resolution of the simulation, and we incorporate a detailed Mont...

Johnson–Cook (J-C) material model is often used for Finite Element (FE) modeling of cutting processes and it affects significantly the results of simulation. Since experimentally determination of J-C equation parameters is an expensive and time-consuming task, in this paper, a new and efficient methodology was implemented based on the evolutionary optimization algorithm to identify new J-C mate...