Wyniki wyszukiwania - BazTech

1

The influence of yttrium addition on the GFA of selected iron-based BMG

Pilarczyk W., Mucha A.

Archives of Materials Science and Engineering

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2010

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Vol. 44, nr 2

87-95

EN

Purpose: The main aims of this work is the presentation of the influence of yttrium addition on the structure and properties of BMG and the production attempt of chosen Fe-based bulk metallic alloys. Design/methodology/approach: The studies were carried out on Fe- based alloys ingots with the following compositions Fe43Co7Cr15Mo14C15B6, Fe41Co7Cr15Mo14C15B6Y2 and Fe39Co7Cr15Mo14C15B6Y4. Samples were prepared by induction melting of the pure Fe, Co, Cr, Mo, C, B and Y elements in argon atmosphere. The structure was tested with X-ray diffraction. In order to investigate the structure scanning electron microscopy was used. The thermal properties of the alloys were examined by DTA and DSC methods. Findings: Bulk metallic glasses with yttrium addition exhibit high glass forming ability. These materials depending on accurate chemical composition present excellent corrosion resistance, magnetic, electric and mechanical properties. Fe-based materials with yttrium addition are potential materials for industrial applications. Research limitations/implications: It is very difficult to obtain a metallic glass of Fe43Co7Cr15Mo14C15B6, Fe41Co7Cr15Mo14C15B6Y2 and Fe39Co7Cr15Mo14C15B6Y4 alloys. All tested alloys have crystalline structure. Taking into account all the factors affecting the test samples, we can conclude that the received samples have not an amorphous structure for the non-uniform distribution of yttrium in materials. Originality/value: Overall presentation of the yttrium addition influence, the formation and the study of Fe-Co-Cr-Mo-C-B-Y bulk metallic materials.

2

A production attempt of selected metallic glasses with Fe and Ni matrix

Pilarczyk W., Nowosielski R., Babilas R.

Archives of Materials Science and Engineering

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2010

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Vol. 41, nr 1

5-12

EN

Purpose: This paper tends to present the microstructure characterization and thermal analysis of the Fe- and Ni-based bulk metallic materials. Design/methodology/approach: The studies were carried out on bulk metallic materials as rods. The rods of the Fe57.6Co7.2Ni7.2B19.2Si4.8Nb4 and Ni64.8Co7.2B19.2Si4.8Nb4 alloys were obtained by the pressure die casting. In order to investigate the structure scanning electron microscopy were used. Phase composition of obtained rods was determined by means of diffractometer. The thermal properties of the studied alloys were examined by differential thermal analysis and differential scanning calorimetry. Findings: The x-ray analysis, microscopic observation and thermal examination revealed that the studied as-cast bulk metallic materials were of amorphous, crystalline and mixed structure. Broad diffraction halo can be seen for rods with diameter of ø=1.5 and 2mm of Fe57.6Co7.2Ni7.2B19.2Si4.8Nb4 alloy. The replacement of Fe by Ni created crystalline structure. Practical implications: Fe- and Ni-based bulk metallic glass systems have been developed because they offer great potential for commercial application. Fe-based ferromagnetic bulk glassy alloys exhibit great magnetic properties. It is very important for their magnetic applications. That alloys can be used as soft electro-magnetic cores for choke coil or noise filter. Ni-based bulk metallic glasses exhibit excellent mechanical properties and corrosion resistance. Originality/value: The formation and studies of the casted Fe- and Ni-based bulk materials and investigation of the effectiveness of the replacement of Fe by Ni.

3

Structure and soft magnetic properties of Fe72B20Si4Nb4 bulk metallic glasses

Nowosielski R., Babilas R., Griner S., Stokłosa Z.

Archives of Materials Science and Engineering

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2009

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Vol. 35, nr 1

13-20

EN

Purpose: The paper presents a microstructure characterization, thermal stability and soft magnetic properties analysis of Fe-based bulk amorphous materials. Design/methodology/approach: The studies were performed on Fe₇ ₂B₂ ₀Si₄Nb₄ glassy alloy in form of ribbons and rods. The amorphous structure of tested samples was examined by X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) methods. The thermal properties of the glassy samples were measured using differential thermal analysis (DTA) and differential scanning calorimetry (DSC). The magnetic properties were determined by the Maxwell-Wien bridge and VSM methods. Findings: The X-ray diffraction and transmission electron microscopy investigations have revealed that the studied as-cast bulk metallic glasses were amorphous. Broad diffraction halo can be seen for all tested samples, indicating the formation of a glassy phase with the diameters up to 2 mm. The fracture surface of rod samples appears to consist of small fracture zones, which leads to breaking of the samples into parts. A two stage crystallization process was observed for studied amorphous alloy. The changes of crystallization temperatures and magnetic properties as a function of glassy samples thickness were stated. Practical implications: The studied Fe-based alloy system has good glass-forming ability and thermal stability for casting bulk metallic glasses, which exhibit good soft magnetic properties, useful for many electric and magnetic applications. Originality/value: The obtained examination results confirm the utility of applied investigation methods in the microstructure, thermal and soft magnetic properties analysis of examined bulk amorphous alloys.