scholarly journals STUDY OF DIFFUSION PROCESSES IN A MULTILAYER TITANIUM-STEEL COMPOSITE UNDER LONG HEATING

Author(s):  
V. N. Arisova ◽  
L. M. Gurevich ◽  
A. F. Trudov ◽  
V. O. Kharlamov ◽  
D. D. Tverdysheva

The paper presents the results of studies of diffusion processes in a five-layer explosion-welded composite titanium VT-20+steel 08Cr18Ni10Ti after heat treatment at temperatures of 850 and 900 ° C and holding times of 20-100 hours. The features of the formation of the microstructure, microhardness, and the chemical composition of the diffusion zones of the composite have been studied using optical and electron microscopy and X-ray spectral analysis.

Author(s):  
V. N. Arisova ◽  
L. M. Gurevich ◽  
V. O. Kharlamov ◽  
D. D. Tverdysheva ◽  
V. A. Izyumsky

The work presents the results of studies on the formation of intermetallic layers in a five-layer explosion-welded composite titanium VT-20+steel 08Cr18Ni10Ti after heat treatment at temperatures of 800, 850 and 900 °C and holding times of 4 and 10 hours. The structure, microhardness, chemical composition of the diffusion zones of the composite were studied using optic, electron microscopy and X-ray spectral analysis.


Author(s):  
R. M. Anderson

Aluminum-copper-silicon thin films have been considered as an interconnection metallurgy for integrated circuit applications. Various schemes have been proposed to incorporate small percent-ages of silicon into films that typically contain two to five percent copper. We undertook a study of the total effect of silicon on the aluminum copper film as revealed by transmission electron microscopy, scanning electron microscopy, x-ray diffraction and ion microprobe techniques as a function of the various deposition methods.X-ray investigations noted a change in solid solution concentration as a function of Si content before and after heat-treatment. The amount of solid solution in the Al increased with heat-treatment for films with ≥2% silicon and decreased for films <2% silicon.


2002 ◽  
Vol 20 (7) ◽  
pp. 619-632 ◽  
Author(s):  
A.A. Ali ◽  
F.A. Al-Sagheer ◽  
M.I. Zaki

Three different modifications of manganese(IV) oxide, viz. cryptomelane, nsutite and todorokite-like, were synthesized by hydrothermal methods. The bulk chemical composition, phase composition, crystalline structure and particle morphology of the resulting materials were determined by thermogravimetry, atomic absorption spectroscopy, X-ray diffractometry, infrared spectroscopy and scanning electron microscopy. The surface chemical composition, texture and structure were assessed using X-ray photoelectron microscopy, nitrogen sorptiometry and high-resolution electron microscopy. The results highlighted the hydrothermal conditions under which such tunnel-structured modifications of manganese(IV) oxide can be successfully synthesized. Moreover, they revealed that (i) the bulk was microcrystalline, (ii) the crystallites were either fibrils (cryptomelane and nsutite) or rod-like (todorokite) with low-index exposed facets, (iii) the surface chemical composition mostly reflected that of the bulk and (iv) the surface texture was linked with high specific areas, slit-shaped mesopores associated with particle interstices and micropores which allowed surface accessibility to the bulk tunnels of the test oxides. The application of such test oxides as shape-selective oxidation catalysts appears worthy of investigation.


2012 ◽  
Vol 730-732 ◽  
pp. 9-14 ◽  
Author(s):  
Bruno Henriques ◽  
Filipe Silva ◽  
Delfim Soares

The purpose of this work was to perform a chemical and mechanical characterization of a preoxidized CoCrMo alumina blasted surface. This is a commonly performed surface treatment used in metal-porcelain systems for dental restorations to remove oxides formed during preoxidation heat treatment from the metal’s surface. CoCrMo dental alloy’s specimens produced by lost wax process were examined in terms of chemical composition using X-Ray fluorescence spectroscopy (XRF), Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Spectroscopy (EDS); in terms of mechanical characteristics through the means of a microhardness test and in terms of surface roughness using a profilometer. It was investigated the chemical composition of various surface conditions: non-preoxidized, preoxidized, ground oxidized surface and sandblasted oxidized surface. After alumina blasting, the oxides level on metal’s surface remained high. Alumina blasting treatment (Ø110 µm) produced an 84% increase of CoCrMo surface hardening and an increase in surface roughness (Ra=0.58 µm). It was found alumina contaminants on the metal’s surface. Therefore, it was concluded that alumina blasting do not entirely removes the oxide layer formed during preoxidation heat treatment. It produced a chemical and mechanical surface modification that can influence the metal-ceramic bond strength.


2021 ◽  
Vol 234 ◽  
pp. 00106
Author(s):  
Houda Labjar ◽  
Hassan Chaair

The synthesis of apatite silicated Ca10(PO4)6-x(SiO4)x(OH)2-x (SiHA) with 0≤x≤2 was investigated using a wet precipitation method followed by heat treatment using calcium carbonate CaCO3 and phosphoric acid H3PO4 and silicon tetraacetate SiC8H20O4 (TEOS) in medium of water ethanol, with three different silicate concentrations. After drying, the samples are ground and then characterized by different analytical techniques like X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning electron Microscopy (SEM) and chemical analysis.


2014 ◽  
Vol 16 (48) ◽  
pp. 26624-26630 ◽  
Author(s):  
C. A. F. Vaz ◽  
A. Balan ◽  
F. Nolting ◽  
A. Kleibert

In situX-ray photoemission electron microscopy reveals the evolution of chemical composition and magnetism of individual iron nanoparticles during oxidation.


2005 ◽  
Vol 20 (9) ◽  
pp. 2480-2485 ◽  
Author(s):  
Kohei Kadono ◽  
Tatsuya Suetsugu ◽  
Takeshi Ohtani ◽  
Toshihiko Einishi ◽  
Takashi Tarumi ◽  
...  

Copper(I) chloride and bromide nanoparticle-dispersed glasses were prepared by means of a conventional copper staining. The staining was performed by the following process: copper stain was applied on the surfaces of Cl−- or Br−-ion-containing borosilicate glasses, and the glasses were heat-treated at 510 °C for various times. Typical exciton bands observed in the absorption spectra of the glasses after the heat treatment indicated that CuCl and CuBr particles were formed in the surface region of the glasses. The average sizes of the CuCl and CuBr particles in the glasses heat-treated for 48 h were estimated at 4.8 and 2.7 nm, respectively. The nanoparticles were also characterized by x-ray diffraction and transmission electron microscopy. Depth profiles of Cu and CuBr concentration in the glass heat-treated for 48 h were measured. Copper decreased in concentration monotonously with depth, reaching up to 60 μm, while the CuBr concentration had a maximum at about 25 μm in depth.


2013 ◽  
Vol 42 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Jing Zhou ◽  
Yanrong Wang ◽  
Zulfi Jahufer

The presence of the semi-permeable layer is determined in Roegneria nutans (Keng.) Keng, Achnatherum inebrians (Hance.) Keng, Hordeum vulgare var. nudum Hook. f., Triticale, Festuca sinensis Keng., and Bromus inermis Leyss. using the lanthanum nitrate tracer method, transmission electron microscopy and energy dispersive X-ray analysis. It was an amorphous membranous structure firmly attached on the external portion of the seed coat. The diversified chemical composition of the semi-permeable layer of the species studied is also analyzed by histochemical staining. R. nutans, A. inebrians, H. vulgare var. nudum, and Triticale were found to contain lipids in the semi-permeable layer. F. sinensis had pectin whereas B. inermis has cellulose in the said layer. DOI: http://dx.doi.org/10.3329/bjb.v42i1.15802 Bangladesh J. Bot. 42(1): 23-29, 2013 (June)


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