• Title/Summary/Keyword: Metallurgical aspects

Search Result 13, Processing Time 0.019 seconds

Gamma and neutron shielding properties of B4C particle reinforced Inconel 718 composites

  • Gokmen, Ugur
    • Nuclear Engineering and Technology
    • /
    • v.54 no.3
    • /
    • pp.1049-1061
    • /
    • 2022
  • Neutron and gamma-ray shielding properties of Inconel 718 reinforced B4C (0-25 wt%) were investigated using PSD software. Mean free path (MFP), linear and mass attenuation coefficients (LAC,MAC), tenth-value and half-value layers (TVL,HVL), effective atomic number (Zeff), exposure buildup factors (EBF), and fast neutron removal cross-sections (FNRC) values were calculated for 0.015-15 MeV. It was found that MAC and LAC increased with the decrease in the content of B4C compound by weight in Inconel 718. The EBFs were computed using G-P fitting method for 0.015-15 MeV up to the penetration depth of 40 mfp. HVL, TVL, and FNRC values were found to range between 0.018 cm and 3.6 cm, between 2.46 cm and 12.087 cm, and between 0.159 cm-1 and 0.194 cm-1, respectively. While Inconel 718 provides the maximum photon shielding property since it offered the highest values of MAC and Zeff and the lowest value of HVL, Inconel 718 with B4C(25 wt%) was observed to provide the best shielding material for neutron since it offered the highest FNRC value. The study is original in terms of several aspects; moreover, the results of the study may be used in nuclear technology, as well as other technologies including nano and space technologies.

Recent Advances in Electrodeposition Technology (전해 석출 기술의 최근 개발 동향)

  • Kim, S.K.;Reddy, R.G.
    • Journal of the Korean institute of surface engineering
    • /
    • v.34 no.6
    • /
    • pp.553-567
    • /
    • 2001
  • Electrodeposition technology is widely used in industry for various kinds of coatings. Modifications in this technology led to several processes to meet various requirements. Electrolysis in ionic liquids has many advantages such as low energy consumption of energy, low pollutant emission and low operating costs. Although ionic liquids have already been used in liquid/liquid extraction processes, only recently their use in electrodeposition was exploited. Electrochemical deposition of composites is an expanding area. Coupled with the progress in the synthesis of nanometric powder, this research will open a large number of innovative materials. Pulse current plating is another electrodeposition technique which yields improved coatings. Although electrodeposition is now regarded as an environmental non-friendly process, it is economically viable and has many inherent advantages. For certain applications, alternatives to electrodeposition have not yet been fully implemented. Hence, continued research in this technology is warranted. This article reviews some recent advances in electrodeposition technology. Aspects of electrodeposition such as electrolysis in ionic liquids, electrodeposition of composites, pulse current plating techniques, metal and alloy deposition, compound deposition and effects of additives are discussed in this review.

  • PDF

Surface Characteristics and Biocompatibility of Titanium Coated with Dentin-derived Hydroxyapatite

  • Kim, Hae-Jin;Son, Mee-Kyung;Lee, Kyung-Ku;Lee, Bo-Ah;Kim, Young-Joon
    • International Journal of Oral Biology
    • /
    • v.37 no.1
    • /
    • pp.9-16
    • /
    • 2012
  • The aim of this study was to evaluate surface characteristics and biological properties of the dentin -derived hydroxyapatite (HA) coating on titanium substrate. Dentinderived HA was obtained from extracted human teeth using a calcination method at $850^{\circ}C$. The commercially pure titanium (cp-Ti, ASTM Grade II) was used as a metallic substrate and a radio frequency magnetron sputtering method was employed as a coating method. Scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) were utilized to investigate the coating aspects and composition. Atomic forced microscopy (AFM) and a surface profiler were used to assess the surface morphology and roughness. Corrosion tests were performed in phosphate-buffered saline at a $36.5{\pm}1^{\circ}C$ in order to determine the corrosion behavior of the uncoated and coated specimens. The biocompatibility of dentin-derived HA coated specimens with fetal rat calvarial cells and human gingival fibroblasts was assessed by SEM and cell proliferation analysis. The results showed that the dentin-derived HA coatings appeared to cover thinly and homogeneously the surfaces without changing of the titanium substrate. The EDX analysis of this the coating surface indicated the presence of Ca and P elements. The mean surface roughness of cp-Ti and dentin-derived coating specimens was $0.27{\mu}m$ and, $1.7{\mu}m$, respectively. Corrosion tests indicated a stable passive film of the dentin-derived HA coating specimens. SEM observations of fetal rat calvarial cells and human fibroblast cells on coated surfaces showed that the cells proliferated and developed a network of dense interconnections. The cells on all specimens proliferated actively within the culture period, showing good cell viability. At day 1 and 3, dentin-derived coating specimens showed 89% and 93% cell viability, respectively, when normalized to cp-Ti specimens. These results suggest that dentin-derived HA coating using the RF magnetron sputtering method has good surface characteristics and biocompatibility.