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P. Dudek

Abstract

In recent years, FDM technology (Fused Deposition Modelling) has become one of the most widely-used rapid prototyping methods for various applications. This method is based on fused fibre material deposition on a drop-down platform, which offers the opportunity to design and introduce new materials, including composites. The material most commonly used in FDM is ABS, followed by PC, PLA, PPSF, ULTEM9085 and mixtures thereof. Recently, work has been done on the possibility of applying ABS blends: steel powders, aluminium, or even wood ash. Unfortunately, most modern commercial systems are closed, preventing the use of any materials other than those of the manufacturer. For this reason, the Department of Manufacturing Systems (KSW) of AGH University of Science and Technology, Faculty of Mechanical Engineering And Robotics purchased a 3D printer with feeding material from trays reel, which allows for the use of other materials. In addition, a feedstock production system for the 3D printer has been developed and work has started on the creation of new composite materials utilising ceramics.

Open access

M. Dudek

Abstract

The paper presents the analysis of formation of interfacial layer during deposition of diamond like carbon film (DLC) on the 316L stainless steel by capacitive plasma discharge in the CH4 atmosphere. The structure of the interfacial layer of DLC film was strongly affected by the temperature increase during the initial stages of the process. Initially, thin interfacial layer of 5 nm has been formed. As the temperature had reached 210°C, the second phase of the process was marked by the onset of carbon atoms diffusion into the steel and by the interface thickness increase. Finally, the growth of chromium carbide interface, the upward diffusion of chromium and nickel atoms to film, the etching and the decrease of the DLC film thickness were observed at 233°C. These investigations were carried out ex-situ by spectroscopic ellipsometry, X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy.

Open access

P. Kuśtrowski, A. Białas, J. Surman and B. Dudek

Determination of the active phase structure in CuO/γ-Al2O3 catalysts by TPR kinetic model discrimination

The results of temperature-programmed reduction with hydrogen of alumina supported copper oxide catalysts were used to find the best model describing the kinetics of Cu ions' reduction. On the basis of the rate determining step of this reaction the structure of copper oxide was revealed. This kinetic approach was compared with BET and UV-vis-DRS results. The catalytic activity of various copper oxide forms was tested in toluene combustion.

Open access

P. Dudek and A. Rapacz-Kmita

Abstract

In the context of product development, the term rapid prototyping (RP) is widely used to describe technologies which create physical prototypes directly from digital data. Recently, this technology has become one of the fastest-growing methods of manufacturing parts. The paper provides brief notes on the creation of composites using RP methods, such as stereolithography, selective laser sintering or melting, laminated object modelling, fused deposition modelling or three-dimensional printing. The emphasis of this work is on the methodology of composite fabrication and the variety of materials used in these technologies.

Open access

M. Mosiałek, M. Przybyła, M. Tatko, P. Nowak, M. Dudek and M. Zimowska

Abstract

Composite cathodes for solid oxide fuel cells composed of metallic silver dispersed in ceramic (La0:8Sr0:2MnO3-σ) matrix were prepared on the surface of solid electrolyte by two-step procedure. First the matrix of controlled porosity was created by sintering mixture of La0:8Sr0:2MnO3-σ powder with the organic polymer beads then the matrix was saturated with AgNO3 solution and sintered again. Such obtained cathodes showed higher electrical conductivity and lower charge transfer resistance in oxygen reduction reaction in comparison to pure ceramic cathodes

Open access

A. Fajkiel, P. Dudek and T. Reguła

Abstract

Magnesium alloys are one of the lightest of all the structural materials. Because of their excellent physical and mechanical properties the alloys have been used more and more often in various branches of industry. They are cast mainly (over 90%) on cold and hot chamber die casting machines. One of the byproducts of casting processes is process scrap which amounts to about 40 to 60% of the total weight of a casting. The process scrap incorporates all the elements of gating systems and fault castings. Proper management of the process scrap is one of the necessities in term of economic and environmental aspects.

Most foundries use the process scrap, which involves adding it to a melting furnace, in a haphazard way, without any control of its content in the melt. It can lead to many disadvantageous effects, e.g. the formation of a hard buildup at the bottom of the crucible, which in time makes casting impossible due to the loss of the alloy rheological properties. The research was undertaken to determine the effect of an addition of the process scrap on the mechanical properties of AZ91 and AM50 alloys. It has been ascertained that the addition of a specific amount of process scrap to the melt increases the mechanical properties of the elements cast from AZ91 and AM50 alloys. The increase in the mechanical properties is caused mainly by compounds which can work as nuclei of crystallization and are introduced into the scrap from lubricants and anti-adhesive agents. Furthermore carbon, which was detected in the process scrap by means of SEM examination, is a potent grain modifier in Mg alloys [1-3].

The optimal addition of the process scrap to the melt was determined based on the statistical analysis of the results of studies of the effect of different process scrap additions on the mean grain size and mechanical properties of the cast parts.

Open access

Mariusz P. Pietras and Sylwia Orczewska-Dudek

Abstract

An experiment was conducted on 600 broiler chickens to determine the effect of using Camelina sativa oil as a dietary component on meat quality indicators. Broiler chickens were raised on litter under standard conditions of feeding and maintenance. In the second period of rearing, the control group (I) received a diet containing 6% rapeseed oil. Experimental groups were fed on a diet containing 3% rapeseed oil and 3% Camelina sativa oil (group II) and 6% camelina oil (group III). At the end of rearing 8 chickens from each group were slaughtered. A simplified analysis of the carcasses was conducted. Blood samples were taken to determine the content of total fat, triglycerides, total cholesterol and its fractions. Muscle samples were analysed for the content of dry matter, total protein and crude fat, fatty acid composition and malonic aldehyde (TBA). The meat was subjected to sensory evaluation. It was found that the introduction of Camelina sativa oil to the grower diet for broiler chickens does not have a negative effect on rearing parameters and carcass quality. What was observed was a tendency to reduce the proportion of abdominal fat in the carcass with increasing level of oil used in compound feed and increases in the total protein content of breast meat in group II receiving 3% of camelina oil. The addition of 6% of Camelina sativa oil to compound feed significantly decreased the content of total cholesterol and its fractions in the blood plasma of chickens in comparison to the other groups. The introduction of 3% and 6% of Camelina sativa oil to chicken diets enriched the breast meat in n-3 PUFA, mainly α-linolenic acid (ALA) and did not impair the flavour qualities of the cooked meat. The meat from chickens fed on a diet containing 6% of camelina oil was characterized by a greater increase of ALA.

Open access

K. Mitura, M. Jedrzejewska-Szczerska, P. Ceynowa, M. Dudek, M. Cicha, I. Kotela and S. Mitura

Abstract

The purpose of this paper is to present the innovative design of microwave plasma system for modification of detonation nanodiamond particles (DNP) using a special rotating drum placed inside the reactor. Nanodiamond particles manufactured by detonation method reveal the biological activity depending on surface functionalization. Plasmachemical modification of detonation nanodiamond particles gives the possibility of controlling surface of nanodiamonds particles in biological tests. In this paper we would like to compare detonation nanodiamond (the grain sizes from 2 to 5 nm) with modified detonation nanodiamond in rotary reactor chamber, by microwave plasma activated chemical vapour deposition (MW PACVD) method in materials research (Raman and FT-IR spectroscopy) and in vitro examinations with full of human blood. The results indicate haemocompatibility of non-modified detonation nanodiamond and modified nanodiamond by MW PACVD method in rotary reactor chamber (modified ND-3) and the presence of haemolysis in commercial detonation nanodiamond.

Open access

P. Maj, B. Adamczyk-Cieslak, M. Slesik, J. Mizera, T. Pieja, J. Sieniawski, T. Gancarczyk and S. Dudek

Abstract

Inconel 718 is a precipitation hardenable nickel-iron based superalloy. It has exceptionally high strength and ductility compared to other metallic materials. This is due to intense precipitation of the γ’ and γ” strengthening phases in the temperature range 650-850°C. The main purpose of the authors was to analyze the aging process in Inconel 718 obtained in accordance with AMS 5596, and its effect on the mechanical properties. Tensile and hardness tests were used to evaluate the mechanical properties, in the initial aging process and after reheating, as a function of temperature and time respectively in the ranges 650°-900°C and 5-480 min. In addition, to link the mechanical properties with the microstructure transmission microscopy observations were carried out in selected specimens. As a result, factors influencing the microstructure changes at various stages of strengthening were observed. The authors found that the γ’’ phase nucleates mostly homogenously in the temperature range 650-750°C, causing the greatest increase in strength. On the other hand, the γ’ and δ phases are formed heterogeneously at 850°C or after longer annealing in 800°C, which may weaken the material.