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Laser treatment with 625 Inconel powder of hot work tool steel using fibre laser YLS-4000

Dobrzański L. A., Jonda E., Pakieła W., Dziekońska M.

Journal of Achievements in Materials and Manufacturing Engineering

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2018

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Vol. 91, nr 2

60--67

EN

Purpose: The purpose of this investigation was to determine the changes in the surface layer (Inconel 625), obtained during the laser treatment of tool-steel alloy for hot work by the use high-power fibre laser. Design/methodology/approach: Observations of the layer structure, HAZ, and substrate material were made using light and scanning microscopy. The composition of elements and a detailed analysis of the chemical composition in micro-areas was made using the EDS X-ray detector. The thickness of the resulting welds, heat affected zone (HAZ) and the contribution of the base material in the layers was determined. Findings: As a result of laser cladding, using Inconel 625 powder, in the weld overlay microstructure characteristic zones are formed: at the penetration boundary, in the middle of weld overlay and in its top layer. It was found that the height of weld overlay, depth of penetration, width of weld overlay and depth of the heat affected zone grows together with the increasing laser power. Practical implications: Laser cladding is one of the most modern repair processes for eliminating losses, voids, porosity, and cracks on the surface of various metals, including tool alloys for hot work. Laser techniques allow to make layers of materials on the repaired surface, that can significantly differ in chemical composition from the based material (substrate material) or are the same. Originality/value: A significant, dynamic development in materials engineering as well as welding technologies provides the possibility to reduce the cost of production and operation of machinery and equipment, among others by designing parts from materials with special properties (both mechanical and tribological) and the possibility of regeneration of each consumed element with one of the selected welding technologies.

2

Abrasive wear of AlSi12-Al2O3 Composite materials manufac tired by pressure infiltration

Kremzer M., Dziekońska M., Sroka M., Tomiczek B.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 3

1255-1260

EN

The aim of this study is to investigate tribological properties of EN AC-AlSi12 alloy composite materials matrix manufactured by pressure infiltration of Al2O3 porous preforms. In the paper, a technique of manufacturing composite materials was described in detail as well as wear resistance made on pin on disc was tested. Metallographic observations of wear traces of tested materials using stereoscopic and confocal microscopy were made. Studies allow concluding that obtained composite materials have much better wear resistance than the matrix alloy AlSil2. It was further proved that the developed technology of their preparation consisting of pressure infiltration of porous ceramic preforms can find a practical application.

3

The influence of sterilization on the properties of the polyethylene used in biomedical applications

Ziębowicz A., Ziębowicz B., Dziekońska M.

Journal of Achievements in Materials and Manufacturing Engineering

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2015

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Vol. 71, nr 2

70--76

EN

Purpose: This paper presents results of studies on the effect of the sterilization process and aging process (for comparison) on the mechanical properties and the surface quality of low density polyethylene PE-LD used in biomedical applications. Design/methodology/approach: In order to determine the changes in the surface structure of polyethylene PE-LD measurement of angle and roughness of samples were made. There were also measured mechanical properties - Shore hardness and tensile strength of PE-LD samples. Findings: Results of this study indicate that the sterilization process and the aging process does not significantly affect the mechanical properties of polyethylene. These processes influence the structure of its surface, which is very important due to the its use in medical. Practical implications: Low density polyethylene PE-LD is used in the manufacturing of laboratory equipment, such as syringes, gloves, laboratory dishes, catheters used in hemodialysis, connectors for the surgical drains, the surgical drains used in the treatment of sinuses, tracheostomy tubes. Originality/value: Results are the base for further investigations of biomedical materials. Research are essential to search for new biomedical applications for polyethylene.

4

Manufacturing of ceramic porous preforms by sintering of Al2O3 powder

Kremzer M., Dobrzański L. A., Dziekońska M., Macek M.

Archives of Materials Science and Engineering

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2015

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Vol. 75, nr 2

63--69

EN

Purpose: The aim of the study is to develop a method of manufacturing porous preforms based on ceramic powder Al2O3 used as the strengthening for the production of modern metal composite materials. Design/methodology/approach: Semi-products were produced by sintering of ceramic powders with addition of the pores forming agent. The material of the preform was Al2O3 powder while as a pores and canals forming agent inside the sintered ceramic skeleton coal and charcoal were used. Particle size measurements of Al2O3 powder, charcoal, and coal using laser particle size measurer were made. Preforms were also observed in the scanning electron microscopy (SEM). Findings: The obtained preforms have a volume fraction of ceramic phase in the range of 20-44% due to the differences of sintering temperature and various portion and coal origin used as pores forming agent. Research limitations/implications: The main limitation of presented method is the possibility of obtaining preforms where a porosity are not exceeding 80%. Where, in the case of using ceramic fibers, the pores may be more than 90% volume fraction of the material. Practical implications: Manufactured ceramic preforms are widely used as a reinforcement for production of composite materials by infiltration methods. This method enables the production of metal and locally reinforced composite products with an exact mapping shape. Originality/value: Results indicate the possibility of obtaining new preforms which are a cheaper alternative to semi-finished products based on ceramic fibers. On the other hand, the use of coal and charcoal as a pores forming agent is an economically justified alternative to previously used materials such as fibers carbon and graphite.

5

Structure and properties of aluminium-silicon matrix composites manufactured by pressure infiltration method

Kremzer M., Dobrzański L., Dziekońska M., Radziszewska A.

Archives of Materials Science and Engineering

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2014

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Vol. 68, nr 2

53--58

EN

Purpose: The goal of the paper is to develop technologies for manufacturing composite materials with casting aluminum alloy matrix reinforced by silicon AN AC-AlSi12 and to investigate the effect of the amount of the pore forming agent in the form of graphite MG 192 on the structure and properties of porous ceramic skeleton infiltrated with liquid aluminum alloy. Design/methodology/approach: The composite was manufactured by the use of porous material pressure infiltration method. Hardness test was carried out with Rockwell method in A scale. The wear resistance was measured by the use of TSM Instruments Tribometer. The tribomiter allows to realize dry friction wear mechanism conditions. Additionally the examinations on stereomicroscope of wear tracks were made. Findings: Composite materials reinforced by porous skeleton manufactured on the base Al2O3 particles show superior in mechanical properties and wear resistance than the aluminum alloy EN AC-AlSi12 constituting the matrix. The developed composite materials also have better wear resistance compared to the matrix. Practical implications: Tested composite materials can be applied in many industry branches, among others, in the automotive, aerospace industry and in manufacturing of professional sports equipment. Originality/value:The investigation results shows that the worked out technology of composite materials manufacturing can find the practical application in the production of near net shape and locally reinforced elements.

6

Possibility of wettability improvement of Al2O3 preforms infiltrated by liquid aluminium alloy by deposition Ni-P coating

Dobrzański L., Kremzer M., Dziekońska M.

Archives of Materials Science and Engineering

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2012

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Vol. 55, nr 1

14-21

EN

Purpose: The purpose of this work is to present the method of wettability improvement of sintered Al2O3 preforms by deposition of Ni-P coating. Design/methodology/approach: The ceramic preforms were manufactured by sintering of powder Al2O3 Alcoa CL 2500, with the addition of pores forming agent in the form of carbon fibres Sigrafil C10 M250 UNS of Company SGL Carbon Group. The internal surfaces of ceramic preforms were coated with Ni-P in order to improve the Al2O3 wettability by the liquid aluminium alloy. Coated by Ni-P ceramic preforms were pressure infiltrated with the liquid EN AC-AlSi12 alloy. Metallographic examinations were made in the scanning electron microscope (SEM) equipped with an energy dispersive spectrometer (EDS) of the structures and chemical composition of obtained materials. Findings: Presented in this paper, deposition technology of Ni-P coating on the inner surfaces of ceramic preform can be used as a method of improving the wettability of porous Al2O3 ceramics by infiltrated liquid aluminium alloy. Practical implications: The composite materials made by the developed method can find application in many industries as the elements of devices where beside the benefits from utilizable properties the small weight is required. Originality/value: The obtained results show the possibility of manufacturing the composite materials by the pressure infiltration method of porous sintered preforms inner coated by Ni-P with liquid aluminium alloy being a cheaper alternative for conventional materials.

7

Corrosion resistance of neodymium composite materials reinforced with metal powders

Dziekońska M., Ziębowicz A., Ziębowicz B., Dobrzański L.A.

Archives of Materials Science and Engineering

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2012

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Vol. 58, nr 2

137--145

EN

Purpose: The goal of the study is to investigate the corrosion resistance of hard magnetic composite materials Nd-Fe-B with 5%, 10% and 15% by weight of iron powder, casting copper alloy with tin CuSn10, steel corrosion-resistant X2CrNiMo17-12-2 and Epidian100 (2.5% by mass) as a binder in a humid environment at 40°C and 5% NaCl solution at 35°C and to determine their current-voltage characteristics. Design/methodology/approach: The investigations of corrosion resistance of hard magnetic composite materials in climate chambers were carried out : test 1 (temperature 40°C, relative humidity 93%, duration 96 h), test 2 (temperature 35°C, 5% NaCl solution, duration 6 h). Pitting corrosion were made in an environment of 5% NaCl solution at 35°C. Findings: The results of corrosion tests allows to determinate that the best corrosion show composite materials with addition of 15% of CuSn10 or X2CrNiMo17-12-2. Practical implications: Composite materials Nd-Fe-B – polymer matrix can greatly expand the application possibilities of hard magnetic materials however further examination to obtain materials with improved properties are still needed. Originality/value: Results show corrosion resistance of Nd-Fe-B - polymer matrix composite materials determined by different methods. Results are the base for further investigations of the impact of corrosion environment on the magnetic properties of such composite materials

8

Properties and structure of the functional composite materials - Nd-Fe-Co-B powder bonded with polymer

Ziębowicz B., Dziekońska M., Dobrzański L. A.

Archives of Materials Science and Engineering

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2011

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Vol. 52, nr 2

74-81

EN

Purpose: This paper presents the material and technological solution which makes it possible obtaining functional composite materials based on the nanocrystalline Nd-Fe-Co-B powder with polymer matrix and shows the possibility of application in different branches of the techniques. Design/methodology/approach: For fabrication of composite materials: Nd-Fe-Co-B powder obtained by rapid quenched technique and for matrix - high density pressureless polyethylene (PEHD) and polyamide (PA12) (2.5 % wt.) were used. Composite materials were compacted by the one-sided uniaxial pressing. The complex relationships among the manufacturing technology of these materials, their microstructure, as well as their mechanical and physical properties were evaluated. Materialographic examination of the structure of composite materials and fractures after decohesion were made. Findings: The main purpose of obtaining this kind of composite materials is broadening possibilities of nanocrystalline magnetic materials application that influence on the miniaturization, simplification and lowering the costs of devices. Composite materials show regular distribution of magnetic powder in polymer matrix. Examination of mechanical properties show that these materials have satisfactory compression strength. Practical implications: The manufacturing of composite materials Nd-Fe-Co-B powder - polymer greatly expand the applicable possibilities of nanocrystalline powders of magnetically hard materials however further examination to obtain improved properties of magnetic composite materials and investigations of constructions of new machines and devices with these materials elements are still needed. Originality/value: Manufacturing processes of functional composite materials obtaining Nd-Fe-Co-B - polymer matrix and determination of their mechanical properties. Results are the base for further investigations such composite materials.