Wyniki wyszukiwania - Biblioteka Nauki

1

Spalanie biomasy a ochrona srodowiska

100%

Tomiczek A.

Ekonatura

|

2009

|

nr 02

17-19

2

Odnawialne zrodla energii. Polska i Unia Europejska

100%

Tomiczek A.

Ekonatura

|

2010

|

nr 04

4-5

3

Magnetic properties of magnetostrictive Tb0.3Dy0.7Fe1.9 / polyurethane composite materials

51%

Dobrzański L. , Tomiczek A. , Nabiałek A. , Stokłosa Z.

Archives of Materials Science and Engineering

|

2011

|

tom Vol. 51, nr 2

97-102

EN

Purpose: The aim of this work was to obtain polyurethane matrix composite materials reinforced with Tb0.3Dy0.7Fe1.9 particles and to observe changes of magnetic properties and magnetostriction of samples with different particle size distributions of Tb0.3Dy0.7Fe1.9 powder and varying volume concentration. Design/methodology/approach: The studies was performed on composite materials with the polyurethane matrix reinforced with Tb0.3Dy0.7Fe1.9 powders. The morphology of powder was examined by scanning electron microscopy (SEM) and analysis of the grain distribution of Tb0.3Dy0.7Fe1.9 powder was made using the Mastersizer 2000 analyser. The changes of magnetostriction and magnetic properties, including hystersis loops and effective permeability with changing applied field are tested. Findings: Analysis establishes a direct connection between magnetic properties and structural characteristics of the Tb0.3Dy0.7Fe1.9 powder size, which was used as reinforcement phase. The increase of particle size distribution of Tb0.3Dy0.7Fe1.9 powder in composite materials amplify the magnetostrictive responses, moreover the change of magnetic properties as a function of volume fraction of Tb0.3Dy0.7Fe1.9 powder were confirmed. Research limitations/implications: Contributes to research on structure and properties of magnetostrictive composite materials with the polymer matrix reinforced with Tb0.3Dy0.7Fe1.9 powders. Practical implications: The polymer matrix in investigated composite materials causes growth of resistivity, limiting this way losses for eddy currents at the high operating frequency of the transducers. In addition the values of permeability of composite materials is nearly constant in investigated frequency range. Originality/value: The obtained results show the possibility of manufacturing the magnetostrictive composite materials based on the Tb0.3Dy0.7Fe1.9 particles, with desired properties in cost effective way in comparison to conventional giant magnetostrictive materials (GMM).

4

Structure and magnetic properties of magnetostrictive Td0.3Dy0.7Fe1.9 / polyurethane composite materials

51%

Dobrzański L. A. , Tomiczek A. , Nabiałek A. , Żuberek R.

Journal of Achievements in Materials and Manufacturing Engineering

|

2010

|

tom Vol. 43, nr 2

527--532

EN

Purpose: The aim of this work is to obtain polyurethane matrix composite materials reinforced by Tb0.3Dy0.7Fe1.9particles and to observe changes of magnetic properties and magnetostriction of samples with different particle size distributions of Tb0.3Dy0.7Fe1.9 powder. Design/methodology/approach: Polyurethane matrix composite materials reinforced by Tb0.3Dy0.7Fe1.9 magnetostrictive particles fabricating method were developed during the investigations, making possible to obtain materials with good physical properties. The influence of the concentration and powder particles size of the Td0.3Dy0.7Fe1.9 on magnetic and magnetostrictive properties were estimated. Metallographic examination of powders morphology and the structure observations of composite materials were made. Findings: Composite materials consisting of Td0.3Dy0.7Fe1.9 particles can extend the possibilities of application the magnetostrictive materials and reduce the cost of their manufacturing. The obtained materials show regular distribution of Td0.3Dy0.7Fe1.9 powder in polyurethane matrix. Research limitations/implications: The advantage of polyurethane matrix magnetostrictive composite materials are their simple technology and lowering manufacturing cost in comparison to monolithic Td0.3Dy0.7Fe1.9. These efforts can be considered as very up-to-date from the scientific point of view. Originality/value: The originality of this investigations is the statement that increasing the size of the Td0.3Dy0.7Fe1.9 particles cause increasing the strain response and this is due to the demagnetization effects.

5

FEM modelling of magnetostrictive composite materials

51%

Dobrzański L. A. , Tomiczek A. , Dziatkiewicz G.

Archives of Materials Science and Engineering

|

2012

|

tom Vol. 53, nr 1

46-52

EN

Purpose: The paper presents a numerical model for the analysis of magnetostriction in composite materials in polymer matrix reinforced by Tb0.3Dy0.7Fe1.9 particles. The properties were determined by taking into account the applied stresses and magnetic field intensity. Design/methodology/approach: The finite element method for simulation the magnetostriction phenomenon was established by theoretical analysis based on experimental results. Findings: Thanks to the finite element method the numerical model has been formulated, enabling to simulate behavior of dynamically exciting rod with the nonlinear constituted model of magnetostrictive effect. The results received from experiments and simulations confirmed accuracy of this model for operating conditions, enabling a selection of magnetostrictive composite material with polymer matrix reinforced with Tb0.3Dy0.7Fe1.9 particles for specific application. Research limitations/implications: It was confirmed that using the finite element method can be a way for reducing the investigation cost. This paper proposes analysis which is efficient with respect to the number of simplifications in numerical model and accuracy of results. Practical implications: The proposed method could be helpful in the design process of magnetostrictive composite materials. Originality/value: Modelling based on the finite element method allows to simulating behavior of dynamically exciting rod with the nonlinear constituted model of magnetostriction phenomenon.

6

Evaluation of selected properties of PA6-copper/graphite composite

51%

Konieczny J. , Chmielnicki B. , Tomiczek A.

Journal of Achievements in Materials and Manufacturing Engineering

|

2013

|

tom Vol. 60, nr 1

23--30

EN

Purpose: The aim of this study was to investigate the possibility of improving the tribological properties and thermal conductivity of composites with structural modification of polyamides by the additions of copper and graphite. Design/methodology/approach: The study involved testing polyamide composites containing metallic powder. As the matrix was used polyamide 6 Tarnamid 27 Natural produced by Azoty Tarnów, which strengthened copper, graphite or molybdenum disulfide with varying participation in the composite. Taken tensile test, Brinell hardness, thermal conductivity and the tribological wear resistance. Analyzed the influence of the type of dopant and the participation of the studied property. Findings: The study showed the desirability of the use of graphite and copper as fillers polyamide. The resulting composites are characterized by satisfactory mechanical properties and thermal conductivity. Applied fillers also showed a positive effect on the value of the coefficient of friction wear him down much. Research limitations/implications: No synergistic effect of fillers on the properties of a ternary mixture polyamide-graphite-copper property in all test. Tribological wear for this material was significantly higher than for the binary mixtures of polyamide-graphite and polyamide-copper. According to the literature, composite reinforced with graphite and copper should have a best tribological properties, far in excess of other subjects. Low wear resistance of this material disqualify applications on the nodes friction. Practical implications: The results obtained newly developed composites, combined with the relatively low price of graphite and copper as compared with the price of molybdenum sulfide II may be reasons to use them as analogues of commercial mixtures of PA with MoS2. Originality/value: The results are original and valuable cognitive nature. They bring a new and expanded information about the effects of fillers on mechanical and physical properties. Unique data on tribological wear resistance depends on the type and amount of filler.

7

Polymer matrix composite materials reinforced by Tb0.3Dy0.7Fe1.9 magnetostrictive particles

45%

Dobrzański L. A. , Tomiczek A. , Tomiczek B. , Ślawska-Waniewska A. , Iesenchuk O.

Journal of Achievements in Materials and Manufacturing Engineering

|

2009

|

tom Vol. 37, nr 1

16-23

EN

Purpose: The goal of this work was to describe manufacturing process of polymer matrix composite materials reinforced by Tb0.3Dy0.7Fe1.9 particles and to observe changes of physical properties (magnetic properties and magnetostriction) of samples with randomly oriented magnetostrictive particles in epoxy matrix and with aligning these particles in the matrix during fabrication process. Design/methodology/approach: Polymer matrix composite materials reinforced by the Tb0.3Dy0.7Fe1.9 magnetostrictive particles fabricating method was developed during the investigations, making it possible to obtain materials with good physical properties. The influence of the concentration of the Td0.3Dy0.7Fe1.9 particles on magnetic and magnetostrictive properties was estimated. Metallographic examination of powder’s morphology as well as EDS and XRD analysis and observations the structure of composite materials were made. Findings: The influence of magnetic particle alignment is observed in the magnetic and magnetostriction responses. The magnetostrictive response improves when the magnetic particles are oriented in magnetic fields and reaches approximately 184 ppm for oriented composite materials with 25% volume fraction of Td0.3Dy0.7Fe1.9 particles. Practical implications: For potential applications in technological devices, such as sensors and actuators, it is desirable to form composite systems by combining magnetostrictive phases with matrix, in order to have giant magnetostrictive effect and, at the same time, to reduce disadvantages of monolithic material. Originality/value: The originality of this work is based on manufacturing process, especially of applying magnetic alignment for ordering Td0.3Dy0.7Fe1.9 particles during polymerization of epoxy matrix.

8

Physical properties of magnetostrictive composite materials with the polyurethane matrix

38%

Dobrzański L. , Tomiczek A. , Szewczyk A. , Piotrowski K. , Gutowska M. , Więckowski J.

Archives of Materials Science and Engineering

|

2012

|

tom Vol. 57, nr 1

21-27

EN

Purpose: The purpose of this study was to determine the thermal and electrical conductivity of composite materials with the polyurethane matrix reinforced with Tb0.3Dy0.7Fe1.9 particles with different particle size distributions and varying volume concentration. Design/methodology/approach: The investigated samples were obtained by casting of the composite materials with the polyurethane matrix reinforced with Tb0.3Dy0.7Fe1.9 particles. There were determined the samples density, electrical properties (by a resistivity measurements), thermal conductivity (by Physical Property Measurement System with thermal transport option), as well as the metallographic investigations (by stereo microscope). Findings: It was found from obtained results that the resistivity value for composite materials filled with larger particle size Tb0.3Dy0.7Fe1.9 was lower than the smaller particles size filled composites. Moreover, it may be noticed that thermal conductivity has an approximate value for different Tb0.3Dy0.7Fe1.9 particle size and the same its volume fraction in matrix. Simultaneously it was also observed that the thermal conductivity of the composite materials did not depend on the temperature within the tested range from 293 to 333 K. Research limitations/implications: Contributes to research on structure and physical properties of magnetostrictive composite materials with the polyurethane matrix reinforced with Tb0.3Dy0.7Fe1.9 particles. Practical implications: The polyurethane matrix in investigated composite materials causes growth of resistivity, limiting this way losses for eddy currents at the high operating frequency of the transducers. Originality/value: The obtained results show the possibility of manufacturing the magnetostrictive composite materials based on the Tb0.3Dy0.7Fe1.9 particles, with desired physical properties (including thermal and electrical one) in cost effective way in comparison to conventional giant magnetostrictive materials (GMM).