Wyniki wyszukiwania - Biblioteka Nauki

1

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

100%

Ziębowicz A. , Ziębowicz B. , Dziekońska M.

|

2015

|

tom 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.

2

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

100%

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

|

tom 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

Manufacturing of ceramic porous preforms by sintering of Al2O3 powder

100%

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

|

tom 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.

4

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

100%

Dobrzański L. , Kremzer M. , Dziekońska M.

|

2012

|

tom 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.