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The Fe-C alloy obtained by mechanical alloying and sintering  [PDF]
R. Nowosielski,W. Pilarczyk
Journal of Achievements in Materials and Manufacturing Engineering , 2006,
Abstract: Purpose: The main aim of this work was to determine structure and properties massive Fe-C materials obtainedby mechanical alloying and sintering.Design/methodology/approach: The results of experiments on the fabrication of powders materials and solidmaterials using pure iron and graphite powders are presented. The powders of the Fe-C alloys obtained bymechanical alloying method and after that the powders were sintering. The sintering process was conducted byusing the impulse-plasma method. In this article the usability of mechanical alloying method and sintering toproduce the massive materials were presented.Findings: The laboratory tests show that, by using the mechanical alloying method, one can produce powderof Fe-6.67% mass.C alloy with intentional chemical constitution and desirable structure. The structure of thematerials is homogeneous and fine-grained and inside the materials didn’t find some impurities and undesirablephases. The sintering by using the impulse-plasma method makes the sinters with close to theoretical densitywith non-variable nanocrystaline microstructure possible. The hardness of the sinters was 1300 HV.Research limitations/implications: The mechanical alloying method is one of the techniques which enablesto improve property of Fe-C alloys. It is possible by refinement of structure and modification of phasescomposition. Nanocrystaline size of grain is advisable to make it in correct technology of producing massivematerials with nanocrystaline structure. All of the presented experiments in this article are conducted on alaboratory scale. At the present time, all over the world, the mechanical alloying and the sintering processes ofnanocrystaline materials are only just in the laboratory scientific research. In the nearest future the producing ofnanomaterials will take place not only in the laboratory and move to the industry.Originality/value: The nanomaterials have an unusual mechanical, physical and chemical properties.
Debye temperature of nanocrystalline Fe-Cr alloys obtained by mechanical alloying  [PDF]
S. M. Dubiel,B. F. O. Costa,J. Cieslak,A. C. Batista
Physics , 2015, DOI: 10.1016/j.jallcom.2015.07.067
Abstract: A series on nanocrystalline Fe100-xCrx alloys prepared by mechanical alloying was investigated with X-ray diffraction (XRD), scanning electron microscopy (SEM) and M\"ossbauer spectroscopy (MS) techniques. XRD and SEM were used to structurally characterize the samples whereas MS permitted phase analysis as well as determination of the Debye temperature, Theta_D. Concerning the latter, an enhancement relative to bulk Theta_D-values was revealed in the range of ca. 40 < x <50. In a sample of Fe55.5Cr44.5 two phases were detected viz. (1) crystalline and magnetic with Theta_D=572(56) K and (2) amorphous and paramagnetic with Theta_D=405(26) K.
Kinetics and Structure of Refractory Compounds and AlloysObtained by Mechanical Alloying
Kinetics and Structure of Refractory Compounds and Alloys Obtained by Mechanical Alloying


材料科学技术学报 , 2001,
Abstract: Refractory compounds are material with interesting properties for structural applications. However, the processing of Such material is a great challenge because of their high melting temperature and limited ductility. Mechanical alloying is a novel technique of producing refractory compounds with specific properties. Kinetical and structural peculiarities of refractory compounds and alloys obtained by mechanical alloying are discussed.
Structure and properties of Al67Ti25Fe8 alloy obtained by mechanical alloying
W. Pilarczyk,R. Nowosielski,M. Jodkowski,K. Labisz
Archives of Materials Science and Engineering , 2008,
Abstract: Purpose: The goal of this work is to investigate structure and properties of powdersAl67Ti25Fe8 alloys obtainedby mechanical alloying.Design/methodology/approach: The powders of the Al67Ti25Fe8 alloys were obtained by mechanicalalloying method in a planetary Fritsh Pulverisette 5 mill. The changes of the constitution phases were tested bymeans of the X-ray diffractometer. The microscopic observation of the shape and size of the powdered materialparticles was carried out by the scanning electron microscope. The cross-sectional microstructure evolution andelement distribution of Al67Ti25Fe8 powder alloys were investigated using backscattering electrons of SEM. Thedistribution of powder particles was determined by a sieve analysis.Findings: The laboratory test shows that, by using the mechanical alloying method, one can produce powderof Al67Ti25Fe8 alloys with intentional chemical constitution and desirable structure. Neither impurities norundesirable phases were observed inside the milled materials.Research limitations/implications: Using refinement of grains and phase modification it is possible toimprove properties of Al67Ti25Fe8 alloy. All of the presented experiments in this article are made on a laboratoryscale. It is intended to develop this laboratory scale technology of production materials with better properties thentraditionally cast materials in order to bring it into full production in industry.Originality/value: In addition a good microstructural homogeneity end first of all mechanical properties wasachieved, also practical application will be possible. The Al-Ti-Fe alloys have been considered to be potentiallyimportant for applications at high temperature owing to their low density end expected high specific strength.
Síntesis y caracterización de Fe40Ni40Ag20 y (FeNi)80Ag20 mecánicamente aleados
Revista de la Facultad de Ingeniería Universidad Central de Venezuela , 2006,
Abstract: mechanical alloying (ma) is a process that has shown to be a versatile tool to produce nanostructured composites and alloys from normally immiscible elements. it has the advantage that the parameters of the process can be varied in order to control the grade of the alloy and the microstructure characteristics. in this form, it is possible to produce magnetic materials with new properties. the phase diagrams of ni-ag and fe ag show that mutual solubility is very low in the liquid state as in the solid state. however, it has been able to obtain partial solid solutions in these systems by mechanical alloying and other techniques. because the ball milling process is a non equilibrium technique, it is possible to force the mixture of immiscible elements. in this work we present a study of the ternary system fe-ag-ni, preparing by mechanical alloying fe40ni40ag20 and (feni)80ag20 in a spex 8000 mixer/mill. then we characterized the samples by x-ray diffraction (xrd), transmission electron microscopy (tem) and m?ssbauer spectroscopy. the nanometric size grain is confirmed by xrd. m?ssbauer spectroscopy indicates the grade of alloying after different milling times.
Mechanical and tribological properties of the surface layer of the hot work tool steel obtained by laser alloying  [PDF]
L.A. Dobrzański,E. Jonda,A. Kriz,K. Lukaszkowicz
Archives of Materials Science and Engineering , 2007,
Abstract: Purpose: The paper presents results on the mechanical and tribological properties examinations of the X40CRMoV5-1 hot work alloy tool steel alloyed with carbide powders using the high power diode laser (HPDL).Design/methodology/approach: Metallographic examinations of the material structures after laser alloying of their surface layer were made on light microscope. The tribological wear relationships using pin-on-disc test were specified for surface layers subject to laser treatment, determining the friction coefficient, and mass loss of the investigated surfaces. Hardness tests were made with Rockwell method in C scale on specimens subjected to the standard heat treatment and alloyed using the high power diode laser at various parameters. X-ray diffraction (XRD) technique was used to investigate crystalline structure and phases in the layers.Findings: Metallographic examinations carried out on the light microscope confirm that the structure of the material solidifying after laser remelting is diversified, which is dependant on the solidification rate of the investigated steels. The investigations carried out made it possible to state that due to the heat treatment and remelting of the X40CrMoV5-1tool steel with the WC, TaC or TiC powders it is possible to obtain the high quality surface layer with no cracks and defects and with hardness significantly higher than the substrate metal.Research limitations/implications: In order to evaluate with more detail the possibility of applying these surface layers in tools, further investigations should be concentrated on the determination of the thermal fatigue resistance of the layers.Practical implications: The alloyed layers which were formed on the surface of the hot work steel have shown significant improvement. Good properties of the laser treatment make these layers suitable for various technical and industrial applications.Originality/value: A modification of tool steels surface using a laser beam radiation, as well as coating them with special pastes containing carbides particles such as tungsten, tantalum and titanium allows the essential improvement of the surface layer properties – their quality and abrasion resistance, decreasing at the same time the surface quality.
Transformation Kinetics on Mechanical Alloying  [PDF]
Igor F. Vasconcelos,Reginaldo S. de Figueiredo
Physics , 2001,
Abstract: We propose and develop a model as an attempt to describe the local mechanism of mechanical alloying. This model is based on the observation of global parameters, such as the volumes of the various phases present in the material, and their transformations during the process. The model is applied to milled Fe-Cu and Fe-N experimental results obtained in previous works. In the milling of Fe-Cu system, four stages, whose features are in accordance with experimental observation, are identified:(i) energy storage; (ii) start of the reaction and speed up of it; (iii) decrease of the reaction rate and (iv) stationary stage. No energy storage stage is observed and no saturation is achieved in the milling of Fe-N system. Moreover, we propose a modification on the global kinetic law introduced by Matteazzi et al. based on the different nature of Fe-Cu and Fe-N systems. This modification allows the extension of the validity of this law.
Mechanical alloying of FeCoCr
Gema González,Dariusz Oleszak,Amaya Sagarzazu,Rafael Villalba
Revista Latinoamericana de Metalurgia y Materiales , 2011,
Abstract: The mechanical alloying of Fe-Co-Cr has been studied from the structural point of view by different techniques: XRD, TEM and M ssbauer spectroscopy, following the transformations taking place during milling. The alloys FeCo, Fe40Co50Cr10 and Fe50Co40Cr10 were prepared by milling of the elemental powders during 1, 2, 5, 10, 20, 40 and 60 h. The kinetics of alloy formation occurs by incorporation of Co and/or Cr in the Fe structure. For the Fe-Co alloy after 10h of milling a mixture of Fe (Co) solid solution and a-Fe is obtained. For the FeCoCr alloys prolonged milling results in Cr incorporation in the FeCo structure and a mixture of Fe (Co) and Fe (Cr) is formed. A grain size in the range of 2-5 nm is reached after 60h of milling El proceso de aleación mecánica de Fe-Co-Cr ha sido estudiado desde el punto de vista estructural por varias técnicas: DRX, MET, Espectroscopía M ssbauer, siguiendo las transformaciones que tienen lugar durante la molienda. Las aleaciones FeCo, Fe40Co50Cr10 y Fe50Co40Cr10 fueron preparadas a partir de los polvos elementales por molienda durante 1, 2, 5, 10, 20, 40 y 60 h. La cinética de formación de aleación ocurre por incorporación del Co y/o Cr en la estructura del Fe. Para la aleación Fe-Co después de 10 h de molienda se obtiene la mezcla de una solución sólida Fe (Co) y a-Fe. Para las aleaciones FeCoCr, la molienda prolongada resulta en la incorporación de Cr en la estructura de FeCo formándose una mezcla de Fe (Co) y Fe (Cr). Un tama o de grano en el orden de 2-5 nm es obtenido después de 60 h de molienda
M ssbauer Study of Mechanical Alloying Fe-Ti and Fe-Ti-N Alloys

TA Popovich,OV Arestov,AAPopovich,AS Kuchma,

材料科学技术学报 , 2001,
Abstract: Mossbauer spectrometry was used to study the peculiarity of formation of nonequilibrium phase in Fe-Ti and Fe-Ti-N systems by mechanical alloying. Mossbauer spectra of powders show the formation of nonequilibrium crystalline phase and intermetallic compounds during a mechanical alloying process depending on the alloy composition and the milling time.
Estudio de la obtención de polvos de una aleación ag - zno mediante aleado mecánico y molienda reactiva, para uso en contactores eléctricos Study of powders production of ag-zno alloy by means of mechanical alloying and reaction milling, for use in electrical contacts
Danny Guzmán,Lilian Navea,Laura Troncoso,Claudio Aguilar
Revista Latinoamericana de Metalurgia y Materiales , 2012,
Abstract: Este trabajo tuvo como objetivo estudiar la obtención de polvos de una aleación Ag-ZnO, mediante un proceso combinado de aleado mecánico y molienda reactiva. El procedimiento experimental se dividió en dos etapas. En la primera de ellas, granallas de Ag y Zn fueron aleadas mecánicamente bajo atmósfera de Ar, utilizando un molino SPEX 8000D. En la segunda etapa, los polvos obtenidos mediante aleado mecánico fueron sometidos a molienda reactiva, bajo atmósfera de aire y utilizando etanol como agente de control. La caracterización microestructural de los polvos fue realizada mediante difracción de rayos X y microscopía óptica. En base a los resultados obtenidos, se concluye que mediante la combinación de aleado mecánico y molienda reactiva, es posible obtener polvos con una fina y homogénea distribución de precipitados de ZnO en una matriz de Ag. The objective of this work was to study the production of powders of Ag-ZnO alloy by means of mechanical alloying and reaction milling. The experimental procedure was divided in two stages. During the first stage, Ag and Zn turnings were mechanically alloyed under Ar atmosphere using a SPEX 8000D mill. In the second stage, the powders obtained by mechanical alloying were milled under air using ethanol as process control agent. The powders microstructural characterization was carried out by X-ray diffraction and optical microscopy. Based on the results obtained it can be conclude that by means of combination of mechanical alloying and reaction milling processes it is possible to obtain a Ag-ZnO alloy with a fine and homogeneous distribution of ZnO precipitates.
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