Zbigniew Rdzawski | Silesian University of Technology (original) (raw)

Papers by Zbigniew Rdzawski

ISSUES, Oct 2010

Purpose: One of the reasons behind the interest in copper titanium alloys was development of new ... more Purpose: One of the reasons behind the interest in copper titanium alloys was development of new materials to substitute copper beryllium alloys. The reason for selecting that material for studies was that in the early stages of decomposition of CuTi4 alloy a spinodal transformation takes place and ordering processes begin. Proper selection of heat treatment and plastic working conditions provides possibilities to produce very wide range of sets of properties by formation of the required alloy microstructure. Therefore the main objective of the study was to capture the changes in precipitation kinetics, especially in the relations between supersaturation and ageing or between supersaturaion, cold deformation and ageing in connection to the changes in microstructure and functional properties (mainly changes in hardness and electrical conductivity).
Design/methodology/approach: Melting of the charge material was conducted in medium-frequency induction furnace, in a graphite crucible. The melted material after bath preparation was poured into a cast iron ingot mould (with graphite grease applied on the inside) of dimensions 35 x 120 x 250 mm. The ingots after casting were peeled. The treated ingots were heated in resistance furnace at 900ºC for 1.5 hour and rolled down on a reversible two-high mill.
Findings: Decomposition of supersaturated solid solution in that alloy is similar to the alloys produced in laboratory scale. The observed differences in microstructure after supersaturation were related to the presence of undissolved Ti particles and increased segregation of titanium distribution in copper matrix including microareas of individual grains. The mentioned factors influence the mechanism and kinetics of precipitation and subsequently the produced wide ranges of functional properties of the alloy.
Research limitations/implications: Cold deformation (50% reduction) of the alloy after supersaturation changes the mechanism and kinetics of precipitation and provides possibilities for production of broader sets of functional properties. It is expected that widening of the cold deformation range should result in more complete characteristics of material properties, suitable for the foreseen applications. Similar effects can be expected after application of cold deformation after ageing.
Practical implications: The elaborated research results present some utilitarian qualities since they can be used in development of process conditions for industrial scale production of strips from CuTi4 alloy of defined properties and operating qualities.
Originality/value: The mentioned factors influence the mechanism and kinetics of precipitation and subsequently the produced wide ranges of functional properties of the Cu-Ti alloys.

Received 15.03.2006; accepted in revised form 30.04.2006

Materials, 2020

The work examines the effect of rhenium addition on the structure and properties of Cu–2Ni–1Si al... more The work examines the effect of rhenium addition on the structure and properties of Cu–2Ni–1Si alloys. The aim of this work was to answer the question of how the addition of rhenium will affect the strengthening mechanisms of rhenium-modified, saturated, plastically deformed and aged Cu–2Ni–1Si alloys. How will this affect the crystallization process? What effect will it have on the properties? Scanning electron microscopy (SEM) and analysis of chemical composition in microareas (energy-dispersive X-ray spectroscopy, EDS), light microscopy, measurements of microhardness and conductivity of the alloys were used for the investigations. Research on chemical and phase composition were carried out with application of transmission electron microscopy (TEM), and scanning transmission electron microscopy (STEM). Modification with rhenium has caused an increase in hardness as a result of precipitation of small phases with rhenium. As the effect of supersaturation, cold plastic treatment as w...

Archives of Civil and Mechanical Engineering, 2020

The research paper presents the impact of the scandium additive and various conditions of the hea... more The research paper presents the impact of the scandium additive and various conditions of the heat treatment on copper mechanical, electrical and heat resistance properties. The performed research works included manufacturing of CuSc0.15 and CuSc0.3 alloys through metallurgical synthesis with the use of induction furnace and following crystallization in graphite crucibles at ambient temperature. Additionally, a CuZr0.15 alloy was produced as a reference material for previously synthesized Cu–Sc alloys. During research, the selection of heat treatment for the produced materials was conducted in order to obtain the highest mechanical–electrical properties ratio. Materials obtained in such a way were next subjected to thermal resistance tests. Parameters of thermal resistance test included temperatures from the range of 200–700 °C and 1 h of annealing time. The research has shown that CuSc0.15 and CuSc0.3 alloys have higher heat resistance after their precipitation hardening compared t...

Archives of Metallurgy and Materials, 2016

This paper presents the research results of CuSn6 alloy strip at semi-hard state, plastically def... more This paper presents the research results of CuSn6 alloy strip at semi-hard state, plastically deformed in the process of repetitive corrugation. The influence of process parameters on the mechanical properties and structure of examined alloy were investigated. Examination in high-resolution transmission electron microscopy (HRTEM) confirmed the impact of the repetitive corrugation to obtain the nano-scale structures. It has been found, that the application of repetitive corrugation increases the tensile strength (R

Key Engineering Materials, 2016

The results of the microstructure and hardness investigations of the Cu-0.8Cr alloy after applica... more The results of the microstructure and hardness investigations of the Cu-0.8Cr alloy after application of severe plastic deformation (SPD) implemented by rolling with the cyclic movement of rolls (RCMR) are presented in this paper. Performed substructure investigations showed that using the RCMR method can refine the microstructure of Cu-0.8Cr alloy to the ultrafine scale. The structure of the Cu-0.8Cr alloy was analyzed using light microscope (LM) and scanning transmission electron microscope (STEM). The quantitative studies of the substructure was performed with "MET-ILO" software, on the basis of images acquired on STEM microscope.

Purpose: The main aim of this work is to investigate effect of cold working following supersatura... more Purpose: The main aim of this work is to investigate effect of cold working following supersaturation of alloy copper in change in electrical conductivity of the finally aged CuTi4 alloy. Next, plots were worked out describing the kinetics of precipitation and recrystallisation from titanium copper, based on results of the electric conductivity measurements using the KJMA (Kolmogorov, Johnson, Mehl, Avrami) relationship. Design/methodology/approach: The energy of the nucleation activation, precipitation, and grain growth was calculated by approximating the segments of the straight lines shown in the plots. Findings: As a result of the electrical conductivity tests, the energy of the nucleation activation, growth, and precipitation of new particles during the ageing, was calculated for the two different variants of CuTi4 alloy processing. Research limitations/implications: As a result of the electrical conductivity tests, and using the KJMA (Kolmogorov, Johnson, Mehl and Avrami) rela...

Cast zinc alloys have similar properties to aluminium alloys. The differences are due to the lowe... more Cast zinc alloys have similar properties to aluminium alloys. The differences are due to the lower melting point and higher density. Zinc has a density of 7.14 g/cm 3 , a melting point of 419.5 °C and the boiling temperature of 906 o C. In the temperature range from 150 to 200 °C, zinc has good susceptibility to plastic deformation. It is also resistant to atmospheric factor influence, but is not resistant to acids. The main use of zinc alloy, is the production of thin-walled casts that require high precision. Zinc alloys are also used for die casting moulds, housings and covers as well as a variety of devices that are used in the precision industry, electrical engineering, automotive and construction industry. Properly performed chemical modification leads to improve of properties of the produced castings. Therefore it is very important to know how the cast structure with the change of the chemical composition by adding metallic modifiers to the liquid metal. In this work there was studied the effect of chemical modification of cast zinc alloy on the properties and microstructure of the alloys before and after modification. Modified alloys were prepared by adding modifiers in the range of 0.1% to 1% in form of Ti- Sr and B as aluminium master alloy and then cast into the metal moulds. Next the thermo-derivative analysis was performed of the modified Zn-Al-Cu alloy, the microstructure investigation was carried out using light microscopy and scanning electron microscopy with EDS X-ray microanalysis usage as well as hardness was measured of the modified Zn-Al-C alloys.

The goal of the work is analysis of the knowledge extent on the bactericidal activity of copper a... more The goal of the work is analysis of the knowledge extent on the bactericidal activity of copper and its alloys. Design/methodology/approach: Analysis of publications on the antibacterial properties of copper in the engineering and medical journals, taking also into account publications on the earliest documented employment of copper as the bactericide or medicine. Findings: Analysis of the investigation results presented in more than 350 scientific publications and reports worked out under commission from the Ministry of Health, including 312 scientific publications from the years 1892-1973, indicate to the antimicrobial action of copper and its alloys, which killing bacteria and viruses slows down growth of the microorganisms, and especially of: cobacillus, Legionella pneumophila, Salmonella, Staphylococcus aureus, poliovirus. Research limitations/implications: Application of the acquired research results in hospitals, outpatients' clinics, and other public medical centres, will make it possible to reduce morbidity resulting from infections, especially of patients after serious medical treatment, operations, or after the complex antibiotic cure which has led them to decline of immunity. Practical implications: Reduction of health care costs is possible in every country by implementation of the acquired investigation results, as a consequence of the decreased treatment costs, by shortening the patients' stay in a hospital. According to the assessment of the Department of Health of the United Kingdom these savings total to 1 billion pounds a year. Originality/value: Implementation of the analysis of results of investigations on the bactericidal activity of copper and copper based alloys will add to the increase of the patients' safety level in the public medical centres.

Journal of Achievements in Materials and Manufacturing Engineering, 2012

© Copyright by International OCSCO World Press. All rights reserved. 2012 ... J. Konieczny a,*, Z... more © Copyright by International OCSCO World Press. All rights reserved. 2012 ... J. Konieczny a,*, Z. Rdzawski a,b a Institute of Engineering Materials and Biomaterials, Silesian University of Technology, ul. Konarskiego 18a, 44-100 Gliwice, Poland b Institute of Non-Ferrous Metals, ul. Sowińskiego 5, 44-100 Gliwice, Poland * Corresponding e-mail address: jaroslaw.konieczny@polsl.pl Received 17.11.2011; published in revised form 01.01.2012 ... Purpose: The aim of the work is to investigate the microstructure of the heat treated and ...

Archives of Materials Science, Nov 1, 2011

J. Konieczny a,*, Z. Rdzawski a,b a Institute of Engineering Materials and Biomaterials, Silesian... more J. Konieczny a,*, Z. Rdzawski a,b a Institute of Engineering Materials and Biomaterials, Silesian University of Technology, ul. Konarskiego 18a, 44-100 Gliwice, Poland b Institute of Non-Ferrous Metals, ul. Sowińskiego 5, 44-100 Gliwice, Poland * Corresponding author: E-mail address: jaroslaw.konieczny@polsl.pl ... Purpose: The aim of the work is to investigate the microstructure heat treated and cold rolled commercial copper alloy CuTi4. Design/methodology/approach: The Investigations of the structure were made on ZEISS SUPRA 25 with EBSD method. ...

The new high strength high electrical conductivity materials are demanded for advanced electric a... more The new high strength high electrical conductivity materials are demanded for advanced electric applications. Among them Cu-Ag and Cu-Nb wires are promising materials for generators of strong and variable magnetic fields production. Review of selected results of the studies into Cu-Ag and Cu-Nb based composite materials shows presence of various, not always well explained, mechanisms and phenomena which are observed during their production, examination and applications. Two classical copper alloys (with silver and with niobium) were selected for the investigations. The third material used in the studies was produced by bundle drawing of niobium wire in copper tube without classical melting and casting. Microstructure, mechanical and electrical properties were presented in relation to processing technology.

Journal of achievements in materials and manufacturing engineering, 2011

Purpose: The properties and the microstructure of cold drown Cu-Nb composites have been investiga... more Purpose: The properties and the microstructure of cold drown Cu-Nb composites have been investigated for their potential use as conductors in high field magnets. Nowadays, there is much activity in the development of such conductors all over the world. Design/methodology/approach: This study was aimed to investigate microstructure, mechanical and electrical properties of Cu-Nb15 wires. The investigated materials have been processed by vacuum furnace melting and casting, further hot forging and cold drawing. Alternatively material has been processed by one of the SPD (severe plastic deformation) method using oscillatory turning die pressing. Microstructure has been observed by optical and electron microscopy technics. Findings: The ultimate tensile strength versus cold deformation degree have been presented. These changes have been discussed in relation to the microstructure evolution. Practical implications: The obtained mechanical and electrical properties (UTS over 900 MPa and ele...

Archives of Civil and Mechanical Engineering

There is a growing demand for new high strength and high electrical conductivity materials for th... more There is a growing demand for new high strength and high electrical conductivity materials for the advanced electric applications. The promising materials for generators used to produce strong and variable magnetic fields are Cu–Ag and Cu–Nb wires. Two classical copper alloys were selected for this investigation. The third material used in the studies was produced by bundle drawing of niobium wire in a copper tube. Microstructure, mechanical and electrical properties were examined in relation to processing technology. Microstructure of Cu–Ag wires consisted of silver-rich bands distributed in a copper-rich matrix, whereas that of the Cu–Nb alloy wire was not homogeneous. Despite significant plastic deformation, globular particles of niobium, which do not contribute to the increase of mechanical properties, were also observed in addition to narrow bands of niobium-rich phase. Multiple drawing of Nb wire bundle in a copper jacket is a promising method for the production of Cu–Nb micro...

A growing trend to use new copper-based functional materials is observed recently world-wide. Wit... more A growing trend to use new copper-based functional materials is observed recently world-wide. Within this group of materials particular attention is drawn to those with ultrafine grain size of a copper matrix. This study was aimed to investigate mechanical properties, electrical conductivity and microstructure in strips of precipitation strengthened copper alloys processed by continuous repetitive corrugation and straightening (CRCS). Tests were performed with the copper alloy strips using original die set construction installed on tensile testing machine. The microstructure was investigated using optical and electron microscopy (TEM and SEM equipped with EBSD). Proposition of semi industrial application of this method have been also presented. The CRCS process effectively reduced the grain size of a copper alloy strips, demonstrating the CRCS as a promising new method for producing ultra fine grained metallic strips.

Purpose: The aim of this work was to investigate microstructure, mechanical properties and deform... more Purpose: The aim of this work was to investigate microstructure, mechanical properties and deformation behaviour of dispersion strengthened nanocrystalline copper produced by powder metallurgy techniques. Design/methodology/approach: Tests were performed with the Cu, Cu-tungsten carbide and Cu-yttria micro-composites containing up to 3 wt.% of a strengthening particles. The mechanical properties, initial nanocrystalline structures and their evolution during deformation processes were investigated. Findings: The obtained strengthening effect have been discussed based on the existing theories related to strengthening of nanocrystalline materials. The studies have shown the importance of "flows" existing in the consolidated materials and sintered materials such as pores or regions of poor powder particle joining which significantly deteriorate mechanical properties of micro-composites produced by powder metallurgy. Research limitations/implications: The powder metallurgy techniques make it possible to obtain copper-based bulk materials by means of milling input powders in the planetary ball, followed by compacting and sintering. Additional operations of hot extrusion are also often used. There is some threat, however, that during hightemperature processing or using these materials at elevated or high temperatures this nanometric structure may become unstable. Practical implications: A growing trend to use new copper-based functional materials is observed recently worldwide. Within this group of materials particular attention is drawn to those with nanometric grain size of a copper matrix, which exhibit higher mechanical properties than microcrystalline copper. Originality/value: The paper contributes to the mechanical properties of dispersion strengthened (with tungsten carbide and yttria) nanocrystalline copper and to the elucidation of deformation behaviour of these materials with high porosity.