scholarly journals Application of methods of ion-vacuum modification of working surfaces of carbide tools to improve their performance

2020 ◽  
Author(s):  
Ю.М. Зубарев ◽  
А.И. Круглов ◽  
М.А. Афанасенков
Keyword(s):  
Chemical Elements ◽  
Multilayer Coating ◽  
Experimental Studies ◽  
Mechanical Tests ◽  
Point Of View ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Cutting Zone ◽  
Fine Turning

В статье описаны механизмы разрушения кромок твердосплавных инструментов под влиянием сил резания в процессе обработки заготовок и воздействия окружающей среды. Рассмотрены варианты разрушения твердосплавных инструментов при обработке без применения СОТС в зоне резания. Приведен анализ основных причин потери работоспособности инструментов из металлокерамических твердых сплавов на операциях чистового точения и растачивания. Приведен анализ многокомпонентных покрытий, в состав которых входят различные комбинации химических элементов, с точки зрения их применимости в различных условиях обработки с учетом имеющихся недостатков таких покрытий. Представлена структура многослойного покрытия, позволяющая увеличить работоспособность металлокерамических твердосплавных инструментов в процессе механической обработки заготовок. Приведены результаты комплексных теоретических и экспериментальных исследований с применением современных методов компьютерного моделирования, рентгеноструктурного анализа, оптической и просвечивающей электронной микроскопии, а так же механических испытаний. The article describes the mechanisms of destruction of the edges of carbide tools under the influence of cutting forces in the processing of workpieces and environmental influences. The options for the destruction of carbide tools during processing without the use of SOTS in the cutting zone are considered. The analysis of the main reasons for the loss of operability of tools made of cermet carbides in the operations of fine turning and boring is given. The analysis of multicomponent coatings, which include various combinations of chemical elements, from the point of view of their applicability in various processing conditions, taking into account the existing disadvantages of such coatings, is given. The structure of a multilayer coating is presented, which allows to increase the performance of cermet carbide tools in the process of machining workpieces. The results of complex theoretical and experimental studies using modern methods of computer simulation, X-ray diffraction analysis, optical and transmission electron microscopy, as well as mechanical tests are presented.

Preparation of PVC/Kaolin Nanocomposites through Solid State Shear Compounding Based on Pan-Milling

2011 ◽  
Vol 694 ◽  
pp. 350-354 ◽  
Author(s):  
Kan She Li ◽  
Ying Hong Chen ◽  
Hong Mei Niu ◽  
Jian Jun Chen
Keyword(s):  
Electron Microscopy ◽  
Tensile Strength ◽  
Solid State ◽  
Impact Strength ◽  
Ambient Temperature ◽  
Mechanical Tests ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Filled Composite

Solid state shear compounding technology (S3C) based on pan-milling is an effective method to prepare polymer/layered mineral composites with nano intercalating structure. The PVC/Kaolin compounding powders were successfully prepared by pan-milling at ambient temperature, and then the PVC/Kaolin nanocomposites were processed by moulding The structure and properties of PVC/Kaolin compounding powder and nanocomposites were investigated by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and mechanical tests. The results showed that the mechanical properties of PVC/Kaolin nanocomposites prepared through S3C based on pan-milling 30 cycles at ambient temperature including elongation, tensile strength and notched impact strength were remarkably improved compared with conventional filled composites. The elongation of PVC / Kaolin nanocomposites with 4 %wt. Kaolin was 274.6%, which is 187.3 % higher than that for a conventional filled composite. The tensile strength was 54.0 MPa, which is 6.3 MPa higher than that for a conventional filled composite. The tensile strength of the nanocomposites with 8 %wt. Kaolin was 57.5 MPa, which is 9.1 MPa higher than that for a conventional filled composite. At the same time, the notched impact strength was 4.9 kJ/m2, which is 1.0 kJ/m2 higher than a conventional filled composite. Strengthening and toughening for PVC were synchronously realized. XRD, SEM and TEM verified that S3C based on pan-milling realized synchronously pulverizing, dispersion and compounding of PVC with kaolin Through 25-30 cycles pan-milling, PVC and Kaolin powders imbedded each other and made into uniform PVC/Kaolin compounding powders and nanocomposites. The strip flake of Kaolin particles with thickness less than 50 nanometer and the aspect ratio of 10 times dispersed homogeneously in the PVC matrix.

scholarly journals Optimized Tin Bismuth Alloy Modified with Silver Vanadate Nanorods Prepared via Powder Metallurgy: Search for Biomedical Application

2020 ◽  
Vol 9 (4) ◽  
pp. 1615-1626
Keyword(s):  
Electron Microscopy ◽  
Powder Metallurgy ◽  
Biomedical Application ◽  
Mechanical Tests ◽  
Bacterial Strains ◽  
X Ray Diffraction ◽  
X Ray ◽  
Silver Vanadate ◽  
Transmission Electron ◽  
Bismuth Alloy

In this study, a new bismuth tin eutectic alloy and other samples of the same composition doped with variable concentration of silver vanadate nanorods were prepared using new route powder metallurgy. X-ray diffraction of prepared silver vanadate approves the formation of  phase silver vanadate (-AgVO3). Transmission electron microscopy shows the formation of AgVO3 nanorods of radius ranging (20-40 nm). X-ray diffraction of alloys doped with silver vanadate and mechanical tests show that hardness and creep behavior data are composition-dependent parameters with silver vanadate content. Antimicrobial tests against pathogenic grams, fungi, and yeast showed that the addition of silver vanadate nanorods stimulates the action of hydride alloy and increases their activity against bacterial strains. In hospitals, biomedical devices may contaminate infection; doping devices with nanoparticles may make it auto clean besides conserving its mechanical properties.

Polypropylene/Ethylene-Octene Copolymer/Organic-Montmorillonite Nanocomposites

2005 ◽  
Vol 13 (2) ◽  
pp. 173-180 ◽  
Author(s):  
Minyan Guo ◽  
Xiaodong Zhou ◽  
Gance Dai ◽  
Fuzeng Hu
Keyword(s):  
Electron Microscopy ◽  
Mechanical Tests ◽  
Polymer Chains ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Organic Montmorillonite ◽  
Melt Compounding ◽  
Transmission Electron ◽  
Ethylene Octene Copolymer

Melt compounding was employed to prepare polypropylene (PP)/ethylene-octene copolymer (POE)/organic-montmorillonite (OMMT) nanocomposites. Polypropylene grafted with maleic anhydride (MPP) was added as a compatibilising agent. Analyses by wide-angle X-ray diffraction, transmission electron microscopy and scanning electron microscopy indicated that polymer chains intercalated into OMMT and that some of the OMMT delaminated into nano-layers dispersed in the PP matrix. Mechanical tests showed that the addition of POE increases the toughness of PP, but it decreases the stiffness. When OMMT and MPP were added, the toughness of PP increased greatly and the stiffness was not changed profoundly. Differential scanning calorimetry was used to study the melt and crystallization behavior of the composites. The results indicate that OMMT and MPP act as effective nucleating agents.

A New Approach for the Synthesis of Nanostructured Polyurethane-Hydroxylapatite-based Hybrid Materials

2011 ◽  
Vol 66 (1) ◽  
pp. 36-42
Author(s):  
Laura Mădălina Popescu ◽  
Roxana Mioara Piticescu ◽  
Tinca Buruiană ◽  
Eugeniu Vasile ◽  
Roxana Truşcă ◽  
...  
Keyword(s):  
Point Of View ◽  
Strong Interactions ◽  
X Ray Diffraction ◽  
Composite Powders ◽  
New Approach ◽  
X Ray ◽  
Transmission Electron ◽  
Ft Ir ◽  
Properties Of Composites

The structural properties of composites prepared by a hydrothermal method in high-pressure conditions and the role of pressure in the formation of hydroxylapatite-polyurethane (HAp-PU) materials with strong interactions between the two components were investigated. X-Ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), FT-IR and NMR analyses were used to characterize the composite powders from a structural, morphological and compositional point of view. Both FT-IR and NMR spectroscopies indicate interactions between hydroxylapatite and acid polyurethane

Synthesis and Characterization of Zn doped Li(Li0.21Mn0.54Ni0.125Co0.125)O2 as the Layer Materials For Battery Applications

2018 ◽  
Vol 21 (2) ◽  
pp. 127-131
Author(s):  
S. Rumh. Kadhim ◽  
Reihan Etefagh ◽  
H. Arabi
Keyword(s):  
Infrared Spectroscopy ◽  
Chemical Elements ◽  
Sol Gel ◽  
Chemical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Physical And Chemical ◽  
And Chemical Properties

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.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

1982 ◽  
Vol 40 ◽  
pp. 722-723 ◽  
Author(s):  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

Transmission electron microscope studies in special ceramics

1978 ◽  
Vol 36 (1) ◽  
pp. 268-269
Author(s):  
A. Zangvil ◽  
L.J. Gauckler ◽  
G. Schneider ◽  
M. Rühle
Keyword(s):  
Phase Diagrams ◽  
Crystal Structures ◽  
Thin Foil ◽  
Limited Extent ◽  
Complex Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Lattice Resolution

The use of high temperature special ceramics which are usually complex materials based on oxides, nitrides, carbides and borides of silicon and aluminum, is critically dependent on their thermomechanical and other physical properties. The investigations of the phase diagrams, crystal structures and microstructural features are essential for better understanding of the macro-properties. Phase diagrams and crystal structures have been studied mainly by X-ray diffraction (XRD). Transmission electron microscopy (TEM) has contributed to this field to a very limited extent; it has been used more extensively in the study of microstructure, phase transformations and lattice defects. Often only TEM can give solutions to numerous problems in the above fields, since the various phases exist in extremely fine grains and subgrain structures; single crystals of appreciable size are often not available. Examples with some of our experimental results from two multicomponent systems are presented here. The standard ion thinning technique was used for the preparation of thin foil samples, which were then investigated with JEOL 200A and Siemens ELMISKOP 102 (for the lattice resolution work) electron microscopes.

A TEM investigation of a hyper-eutectic lead-tin alloy

1988 ◽  
Vol 46 ◽  
pp. 562-563
Author(s):  
John A. Sutliff
Keyword(s):  
Volume Diffusion ◽  
Eutectic Mixture ◽  
Precipitation Reaction ◽  
Directionally Solidified ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Diffusion Controlled ◽  
Discontinuous Precipitation Reaction ◽  
Controlled Precipitation

Near-eutectic Pb-Sn alloys are important solders used by the electronics industry. In these solders, the eutectic mixture, which solidifies last, is the important microstructural consituent. The orientation relation (OR) between the eutectic phases has previously been determined for directionally solidified (DS) eutectic alloys using x-ray diffraction or electron chanelling techniques. In the present investigation the microstructure of a conventionally cast, hyper-eutectic Pb-Sn alloy was examined by transmission electron microscopy (TEM) and the OR between the eutectic phases was determined by electron diffraction. Precipitates of Sn in Pb were also observed and the OR determined. The same OR was found in both the eutectic and precipitation reacted materials. While the precipitation of Sn in Pb was previously shown to occur by a discontinuous precipitation reaction,3 the present work confirms a recent finding that volume diffusion controlled precipitation can also occur.Samples that are representative of the solder's cast microstructure are difficult to prepare for TEM because the alloy is multiphase and the phases are soft.

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