Journal ArticleDOI
The surface energies of solid molybdenum, niobium, tantalum and tungsten
TLDR
The surface energies of solid molybdenum, niobium, tantalum, and tungsten at 1500 °C have been determined using the multi-phase equilibration technique.Abstract:
The surface energies of solid molybdenum, niobium, tantalum, and tungsten at 1500 °C have been determined using the multi-phase equilibration technique The values obtained were 2050, 2550, 2680 and 2830 erg/cm2, respectively The grain boundary energy/surface energy ratios for the four metals varied from 028 to 038 with an average of 032read more
Citations
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Journal ArticleDOI
Surface free energies of solid metals: Estimation from liquid surface tension measurements
W.R. Tyson,W.A. Miller +1 more
TL;DR: In this paper, a semi-theoretical approach was proposed to estimate the surface energy of solids in the absence of direct experimental measurement. But this method was not suitable for the case of high-index surfaces.
Journal ArticleDOI
On the measurement of surface free energy and surface tension of solid metals
V. K. Kumikov,Kh. B. Khokonov +1 more
TL;DR: In this paper, the surface free energy and surface tension of solid metals reported in the literature are compared and preferred values for preferred values are suggested, the basic criteria which determine the value of obtained results are shown.
Journal ArticleDOI
Surface energies of solid metals
TL;DR: In this paper, a brief review of theories of surface free energy and surface entropy is presented, and it is suggested that S ∼ 1.0 R per mole of surface atoms is a reasonable estimate.
Journal ArticleDOI
Thin intergranular films and solid-state activated sintering in nickel-doped tungsten
TL;DR: Nickel-doped tungsten specimens were prepared with high purity chemicals and sintered. High resolution transmission electron microscopy and Auger electron spectroscopy revealed the presence of nanometer-thick, nickel-enriched, disordered films at grain boundaries well below the bulk eutectic temperature as mentioned in this paper.
Journal ArticleDOI
Segregation-induced grain boundary premelting in nickel-doped tungsten
TL;DR: In this paper, high-resolution transmission electron microscopy and Auger spectroscopy have revealed the formation of nanometer-thick, Ni-enriched, disordered, grain boundary layers in Ni-doped W specimens at 95 °C below the bulk eutectic temperature.
References
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Journal ArticleDOI
Determination of the Surface Tension and Surface Migration Constants for Tungsten
TL;DR: In this article, the surface tension and surface migration constants of tungsten were determined using pulsed field emission microscopy (PEEM) based on Herring's theory of transport phenomena in solids.
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A theory of surface tension of solids—I application to metals
TL;DR: In this article, a theory is developed which allows one to calculate the surface tension of nonionic solids (metals and nonmetals) from the arrangement of their next neighbors, from the heat of fusion, and from the surface tensor of the liquid at the melting point.
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Crack propagation in single crystals of tungsten
TL;DR: In this article, the effect of pre-existing micro-cracks on the fracture of tungsten single crysta's has been investigated and the results showed that the fracture stress was dependent on the crack length according to the Griffith criterion.
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Fringe spacing in interference microscopes
F R Tolmon,Jill G Wood +1 more
TL;DR: In the case of interference microscopes, with high-powered objective lenses producing strongly convergent incident light, experiments show that the equivalent value of the fringe spacing is approximately 10% greater than half the wavelength, a discrepancy due to the obliquity of the rays as discussed by the authors.
Journal ArticleDOI
Surface tension of liquid metals
TL;DR: In this article, the results of surface tension measurements by all reported techniques are collated and examined, and the lack of reproducibility and wide scatter is discussed; it is suggested that more fundamental values would be obtained if values for liquid metal density were determined by techniques independent of surface-tension corrections.