ASTRONOMY AND ASTROPHYSICS High precision difference astrometry applied to the triplet of S5 radio sources B1803+784/Q1928+738/B2007+777 Abstract. We determined the separations of the radio sources in the triangle formed by the BL Lac objects 1803+784 and 2007+777, and the QSO 1928+738 from in-tercontinental interferometric observations carried out in November 1991 at the frequencies of 2.3 and...

Abstract The thermal analysis is performed on a heated Inconel 617 honeycomb-core sandwich panel. Sandwich panel is supported at its four edges with spar-like sub-structures that acted as heat sinks, which are generally not considered in the classical analysis. One side of the panel is subjected to a heat flux on the surface. Two types of surface heating were considered: (1) hexagonal honeycomb...

ABSTRACT Inconel 718 is a difficult-to-cut nickel-based superalloy commonly used in aerospace industry. This paper presents an experimental study of the tool wear propagation and cutting force variations in the end milling of Inconel 718 with coated carbide inserts. The experimental results showed that significant flank wear was the predominant failure mode affecting the tool life. The tool fla...

The damage accumulation behavior of different grain boundary structures in Inconel 690 (Ni-29wt%Cr-9wt%Fe) was investigated in the presence of large, localized plastic strains induced by nanoindentation. Spatially-resolved hardness was measured as a function of lateral distance from ‘random’ high-angle grain boundaries and twin boundaries. The confinement of induced defects between the indenter...

The effects of cutting tool coating material and cutting speed on cutting forces and surface roughness were investigated by Taguchi experimental design. Main cutting force, Fz is considered as a criterion. The effects of machining parameters were investigated using Taguchi L18 orthogonal array. Optimal cutting conditions were determined using the signal-to-noise (S/N) ratio which is calculated ...