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- Matysiak, Hubert, et al.
(author)
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Microstructure of Haynes® 282® Superalloy after Vacuum Induction Melting and Investment Casting of Thin-Walled Components
- 2013
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In: Materials. - : MDPI AG. - 1996-1944. ; 6:11, s. 5016-5037
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Journal article (peer-reviewed)abstract
- The aim of this work was to characterize the microstructure of the as-cast Haynes® 282® alloy. Observations and analyses were carried out using techniques such as X-ray diffraction (XRD), light microscopy (LM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray spectroscopy (EDS), wave length dispersive X-ray spectroscopy (WDS), auger electron spectroscopy (AES) and electron energy-loss spectrometry (EELS). The phases identified in the as-cast alloy include: γ (gamma matrix), γʹ (matrix strengthening phase), (TiMoCr)C (primary carbide), TiN (primary nitride), σ (sigma-TCP phase), (TiMo)2SC (carbosulphide) and a lamellar constituent consisting of molybdenum and chromium rich secondary carbide phase together with γ phase. Within the dendrites the γʹ appears mostly in the form of spherical, nanometric precipitates (74 nm), while coarser (113 nm) cubic γʹ precipitates are present in the interdendritic areas. Volume fraction content of the γʹ precipitates in the dendrites and interdendritic areas are 9.6% and 8.5%, respectively. Primary nitrides metallic nitrides (MN), are homogeneously dispersed in the as-cast microstructure, while primary carbides metallic carbides (MC), preferentially precipitate in interdendritic areas. Such preference is also observed in the case of globular σ phase. Lamellar constituents characterized as secondary carbides/γ phases were together with (TiMo)2SC phase always observed adjacent to σ phase precipitates. Crystallographic relations were established in-between the MC, σ, secondary carbides and γ/γʹ matrix.
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2. |
- Wróbel, P., et al.
(author)
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Fabrication of corrugated Ge-doped silica fibers
- 2012
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In: Optics Express. - 1094-4087 .- 1094-4087. ; 20:13, s. 14508-14513
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Journal article (peer-reviewed)abstract
- We present a method of fabricating Ge-doped SiO2 fibers with corrugations around their full circumference for a desired length in the longitudinal direction. The procedure comprises three steps: hydrogenation of Ge-doped SiO2 fibers to increase photosensitivity, recording of Bragg gratings with ultraviolet light to achieve modulation of refractive index, and chemical etching. Finite-length, radially corrugated fibers may be used as couplers. Corrugated tapered fibers are used as high energy throughput probes in scanning near-field optical microscopy.
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3. |
- Wróbel, P., et al.
(author)
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Preparation of high energy throughput SNOM probes
- 2011
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In: 13th International Conference on Transparent Optical Networks, ICTON 2011, Stockholm, 26-30 June 2011. - 2162-7339. - 9781457708800
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Conference paper (peer-reviewed)abstract
- In this technical note we present technological steps of fabrication of high energy throughput SNOM probes. The core-metal coating interface of probes is corrugated what enhances photon-to-plasmon coupling. A strong evanescent field allows for reduction of aperture diameter, which together with skin depth of metal used for coating decide upon resolution. Probes are made of Ge-doped silica glass fibre, which is hydrogenated to increase its photosensitivity. A Bragg grating is recorded in the cores with UV light diffracted into +1 st/1st diffraction orders on a sinusoidal phase mask. Modulation of the refractive index is connected with different etch rates. Etching with the Turner method is made in aqueous solution of HF acid. A corrugated tapered fibre is then coated with aluminium in a special rotating holder. We present results of this novel multi step technology.
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