Growth Kinetics and Mechanical Characterization of a Hard Boron Coating on a Tool Steel

2017 ◽  
Vol 380 ◽  
pp. 29-34 ◽  
Author(s):  
D. Sánchez Huerta ◽  
N. López Perrusquia ◽  
I. Hilerio Cruz ◽  
M.A. Doñu Ruiz ◽  
E.D. García Bustos ◽  
...  

The mechanical characteristics are determined to a FeB/Fe2B coating applied in AISI L6 steel tool and blades make to cut paper. The thermochemical treatment was applied at temperatures of 1173, 1223 and 1273 K with permanence time of 0.5, 2 and 3 h for each temperature. The diffusion coefficient and activation energy for each phase is obtained for this boron coating on an AISI L6 steel. HRC test were made to establish the type of adherence (qualitative) and comparing with the VDI 3198 standard and the results were obtaining optimal classification of HF1-HF2 in condition for 3h of the three temperatures. The result by nanoidentation show hardness of 1000 - 2000 HV as well as the Young's modulus for each present phase of the coating. Through micrographs (SEM) are showing thicknesses up to 79.52 ± 18.82 μm for FeB and 97.80 ± 20.01μm for Fe2B, a morphology sawn ́s type is evidence. Through EDS and x-ray diffraction are used to show the chemical elements formed.

2019 ◽  
Vol 28 (1) ◽  
pp. 51-56
Author(s):  
Anastazia Melnik ◽  
Luciano Nascimento

The present work aimed to characterize the microstructure of the icosahedral phase (quasicrystalline phase-ϕ) of the system with stoichiometric composition of the quasicrystal Al63Cu25Fe12. The ternary alloy with nominal composition of Al63Cu25Fe12 was processed by mechanical alloying (MA) as a viable solid state processing method for producing various metastable and stable quasicrystalline phases. The structural characterization of the obtained samples was performed by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM), while the elemental composition of the chemical elements Al, Fe and Cu were determined by X-ray spectroscopy technique of dispersive energy (EDS). According to the results of XRD, the diffraction patterns of Al63Cu25Fe12 showed the presence of β-Al(Fe, Cu) and λ-Al13Fe4 phases coexist with the thermodynamic ϕ-phase quasicrystalline. Finally, elemental analysis indicates that during alloy synthesis there is little variation of the ideal composition. The results indicate that alloys with high percentage of icosahedral phase can be obtained by casting in the air.


MRS Advances ◽  
2018 ◽  
Vol 3 (64) ◽  
pp. 3971-3978 ◽  
Author(s):  
O.E. Villanueva-Perez ◽  
I. Mejía ◽  
V. García-García ◽  
A. Bedolla-Jacuinde

ABSTRACTLow density (LD) steels have shown particular characteristics in terms of mechanical properties and microstructure, since they have high strength, high ductility and density reduction up to 18%. On the other hand, the addition of microalloying elements such as Ti and B generate hardening by solid solution and precipitation, as well as grain refinement effect. LD steels generate nano-sized kappa phase precipitated from the austenite matrix, and these advanced steels can reach strength and elongation up to 780 MPa and 60%, respectively. The main objective of this research work is the metallographic, structural and mechanical characterization of a LD steel microalloyed with Ti/B in as-cast and -homogenized conditions. For this purpose a Fe-27Mn-7Al-1.2C (%wt) LD steel microalloyed with Ti/B was melted in a vacuum-induction furnace and cast in metallic mold. LD-Ti/B steel samples were homogenized at 1100 °C during 20, 50, 100, 150 and 200 minutes followed by water quenching. Metallographic, structural and mechanical characterization was carried out by optical (LOM) and scanning electron (SEM) microscopy, X-ray diffraction (XRD) and microhardness Vickers testing (HV10), respectively. In general, results showed a typical dendritic microstructure with average grain size of 1256 μm in the as-cast condition. On the other hand, the as-homogenized condition showed an austenitic equiaxial microstructure with average grain size from 164 to 940 μm. Austenite, ferrite and kappa phases were detected by X-ray diffraction (XRD). Also, second-phase particles such as AlN, TiC and MnS were detected by LOM and SEM-EDS analysis. LD steel microalloyed with Ti/B exhibited the highest microhardness Vickers value (235 HV10) in the as-cast condition, whilst in the as-homogenized condition microhardness gradually decreases from 223 to 198 HV10 as holding time increases.


2004 ◽  
Vol 11 (01) ◽  
pp. 83-86 ◽  
Author(s):  
S. ABOUELHASSAN ◽  
F. SALMAN ◽  
M. ELMANSY ◽  
E. SHEHA

Single crystals of KHCO 3 were grown by the slow evaporation technique of an aqueous solution. Characterization of the sample was done using different techniques such as X-ray diffraction, infrared spectra (IR) and the differential scanning calorimeter (DSC) technique. The analysis of the X-ray diffraction pattern indicated that the sample was a single crystal. The results obtained by IR and DSC indicated the presence of phase transition. From the analysis of DSC, the activation energy of transition was carried out by two methods (Kissinger and Ozawa).


2019 ◽  
Vol 34 (1) ◽  
pp. 163
Author(s):  
Helen Jamil Khoury ◽  
Roberto Araújo ◽  
Sandra De Brito Barreto ◽  
Viviane Khoury Asfora

No presente trabalho são 1 apresentados os resultados de estudos por fluorescência de raios X de tijolos brasileiros. Neste estudo foram avaliados 22 tijolos, sendo sete de Igarassu, dois do Forte do Brum e 13 de Olinda. Um equipamento portátil de fluorescência de raios X por dispersão de energia foi desenvolvido para este estudo. Análises por difração de raios X também foram efetuadas para determinar as fases cristalinas presentes nos tijolos. Os resultados mostraram a existência de fases minerais, como quartzo, em todos os tijolos avaliados. A Análise da Componente Principal foi aplicada aos dados dos espectros de fluorescência de raios X obtidos. Os resultados mostraram que a partir do gráfico de scores das componentes principais CP1 e CP3, respectivamente representadas pelo Fe e Ca, foi possível separar os tijolos de Igarassu e do Forte do Brum em cinco grupos, que estavam associados com o século de fabricação. Por sua vez, os tijolos de Olinda foram separados em dois grupos, sendo um formado por um único tijolo e o outro grupo pelos demais tijolos. Estes resultados sugerem que os tijolos foram produzidos com diferentes matérias primas ou em diferentes locais. ENERGY DISPERSIVE X-RAY FLUORESCENCE APPLIED TO THE CHARACTERIZATION OF BRICKS OF PERNAMBUCO HISTORICAL SITESABSTRACTThis work presents the results of X-ray fluorescence analysis of Brazilian bricks, collected from several historical sites of the State of Pernambuco, Brazil. In this study, twenty two bricks were analyzed; seven from Igarassu, two from Forte do Brum in Recife, and thirteen from Olinda. A portable X-ray fluorescence system was assembled and used for the qualitative determination of the chemical elements present in the samples. X-ray diffraction analysis was also carried out to determine the crystal mineral phases in the bricks. All the bricks studied showed several minerals, such as quartz A Principle Component Analysis was applied to the full X-ray fluorescence spectra. In the score plot of principal components PC1 and PC3, represented by Fe and Ca respectively, it can be seen that the results for the bricks from Igarassu and Forte do Brum may be grouped in five clusters corresponding to the bricks´ century and manufacture locations. The analysis of the Olinda bricks yielded two separate groups, one with a single brick and the second group with the other eleven bricks. These results suggest that the bricks were produced with different raw-materials or manufactured in different locations.KEYWORDS: non-destructive analysis; X-ray fluorescence; cultural heritage; bricks; X-ray diffraction.


2021 ◽  
Vol 3 (1) ◽  
pp. 177-187
Author(s):  
Neha Nagar ◽  
◽  
Himanshi Garg ◽  
Chandra Sekhar Gahan ◽  
◽  
...  

The present study aims for characterization and classification of five different spent petroleum refinery catalysts followed by metal recovery via bioleaching. The nomenclature given to the different spent catalyst (SC) is SC1, SC2, SC3, SC4 and SC5 collected from an Indian petroleum refinery. All spent catalysts were crushed and ground prior to their characterization by X-Ray Fluorescence for chemical composition followed by X-Ray Diffraction and Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy for their mineralogy. Further, all five spent catalysts were classified based upon their chemical composition and mineralogy. Metal recovery from the spent catalysts was carried out by bioleaching by a mixed microbial consortium of iron and Sulphur oxidizing microorganisms. Most of the spent catalysts showed very significant metal recovery with respect to Ni, Cu, Cr, Mo, Zn, Sr and Ti. The study provides a possible metal recovery route via bioleaching for further testing and scaling up.


2006 ◽  
Vol 20 (08) ◽  
pp. 427-437 ◽  
Author(s):  
Q. MADUEÑO ◽  
D. A. LANDÍNEZ TÉLLEZ ◽  
J. ROA-ROJAS

We report systematic studies of Ba 2 NdSbO 6 as substrates for the production of YBa 2 Cu 3 O 7-δ superconducting thin films. Chemical stability and crystallographic coupling between Ba 2 NdSbO 6 and YBCO were examined by characterizing Ba 2 NdSbO 6- YBa 2 Cu 3 O 7-δ (0 to 100 vol.%) polycrystalline composites. X-ray diffraction experiments showed that Ba 2 NdSbO 6 belongs to the complex cubic perovskite family. Moreover, we determine that these materials are chemically stables, e.g. there is no chemical reaction at the interface, and the lattice parameters evidenced a matching ~ 2%. Morphological characterization of our samples was performed through scanning electron microscopy, which revealed the existence of separated grains of Ba 2 NdSbO 6 and YBa 2 Cu 3 O 7-δ. Compositional analysis of samples was performed by energy dispersive X-ray experiments, which showed the inexistence of impurities or undesired chemical elements. DC susceptibility measurements permitted us to determine that the presence of Ba 2 NdSbO 6 does not affect the critical temperature of the superconducting transition of YBa 2 Cu 3 O 7-δ. Our results evidenced that Ba 2 NdSbO 6 is an excellent candidate as a substrate for the fabrication of YBa 2 Cu 3 O 7-δ superconducting thin films.


2018 ◽  
Vol 21 (2) ◽  
pp. 127-131
Author(s):  
S. Rumh. Kadhim ◽  
Reihan Etefagh ◽  
H. Arabi

In this paper, pure and impure nanopowders of Li(Li0.021Mn0.54Ni0.125Co0.125)O2 were prepared with different percentages (x=0.02%, 0.05%, 0.075%, 0.10%) of Zn impurity by sol-gel method, and the effect of different percentages were investigated on the structural, physical and chemical properties of the samples. These properties of samples characterized by X-ray diffraction (XRD), field-scattering microscopy (FESEM), X-ray energy spectroscopy (EDS), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), differential thermal analysis (DTA), infrared spectroscopy (FTIR), and the results of characterization were investigation. All the reflection peaks indicate that the samples have standard α-NaFeO2 layered structure with the space group R3m, except for the super lattice ordering between 22°-25°.The FESEM images have shown that these nanoparticles have Hexagonal structures for doped and undoped nanopowders. The particle size of nanopowders in the range of 30-80 nm the chemical analysis of EDS has proven the presence of Zn in the samples. TG /DTA measurements showed weight loss in pure and impure of nanopowders. In infrared spectroscopy (FTIR), the connection bonds and chemical elements used in these nanopowders have been investigated.


2016 ◽  
Vol 869 ◽  
pp. 946-951 ◽  
Author(s):  
Pedro Akira Bazaglia Kuroda ◽  
Marília Afonso Rabelo Buzalaf ◽  
Carlos Roberto Grandini

Titanium is used in the biomedical field due to its mechanical strength/density, corrosion resistance, and biocompatibility. In this paper, the preparation, and the structural, microstructural, and mechanical characterization of Ti-20Zr-2.5Mo and Ti-20Zr-7.5Mo alloys are presented. The elements were melted into an arc furnace with an argon controlled atmosphere. To determine the amount of impurities present in each alloy, an analysis of the chemical composition was conducted using EDS. The samples were characterized by measurements of density, X-ray diffraction (with the diffractograms refined by the Rietveld method), and optical and scanning electron microscopy. The mechanical properties were evaluated using Vickers microhardness test and modulus of elasticity. The results showed that that α’/α’’ and α’'/β phases coexisted in both of the prepared alloys, respectively. The alloys have higher hardness than cp-Ti and their modulus of elasticity values are very close to the modulus values of cp-Ti.


2009 ◽  
Vol 1243 ◽  
Author(s):  
I. Estrada-Guel ◽  
J. L. Cardoso ◽  
C. Careño-Gallardo ◽  
J. M. Herrera-Ramírez ◽  
R. Martínez-Sánchez

ABSTRACTAluminum-based composites prepared from pure Al powder and previously Cu metallized graphite are fabricated by a solid state route and are characterized by X-ray diffraction and scanning electron microscopy in order to follow their microstructural evolution. Composites are processed using powder metallurgy technique in order to obtain cylindrical samples to carry out mechanical testing. Microstructural and mechanical characterizations reveal that, by milling, a homogeneous dispersion of insoluble particles into the Al matrix is obtained; this produces an important improvement in hardness and strength with respect to an un-milled sample. Milling intensity and particle concentration have an important effect on the mechanical properties of the synthesized composites.


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