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Microstructure and service properties of copper alloys

Polok-Rubiniec M., Konieczny J., Labisz A., Włodarczyk-Fligier A.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 3

1277--1282

EN

This elaboration shows the effect of combined heat treatment and cold working on the structure and utility properties of alloyed copper. As the test material, alloyed copper CuTi4 was employed. The samples were subjected to treatment according to the following schema: 1st variant - supersaturation and ageing, 2nd variant - supersaturation, cold rolling and ageing. The paper presents the results of inicrostructure, hardness, and abrasion resistance. The analysis of the wipe profile geometry was realized using a Zeiss LSM 5 Exciter confocal microscope. Cold working of the supersaturated solid solution affects significantly its hardness but the cold plastic deformation causes deterioration of the wear resistance of the finally aged CuTi4 alloy.

2

Influence of aging time and temperature on diffusion of alloyed copper

Konieczny J., Rdzawski Z., Bańbura P., Preficz B.

Journal of Achievements in Materials and Manufacturing Engineering

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2015

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Vol. 73, nr 1

27--35

EN

Purpose: The aim of this study is to determine the impact of aging time and temperature on the diffusion process of alloying elements inside alloyed copper CuCr0,7, CuFe2 and CuTi4. Design/methodology/approach: It was assumed the activation energy for diffusion of small interstitial atoms is smaller than for large substitute atoms. To determine the influence of aging time and temperature on diffusion of alloying elements in binary copper-based alloys CuCr0,7, CuFe2 and CuTi4 it has been necessary to develop a suitable mathematical model. It has been shown that with the increase of time t, the diffusion pathway L is increased, but the impact of time is not as large as the effect forced by altering temperature. In general, multiple increase of time is equivalent to increasing the temperature by a few degrees. Findings: The model should be used to estimate the average atom pathway of chromium, iron or titanium in copper matrix, caused by diffusion, and the diffusion path into the grain boundary without adsorption as a function of time and temperature aging Research limitations/implications: The model should be used to calculate the influence of temperature and time of aging on the atoms diffusion pathway of the alloying elements in the selected alloyed copper types. Practical implications: The results allow to calculate the average atom pathway L (with reasonable error level) for which the diffused atoms achieve the amount of free energy required to overcome the energetic barrier, on the basis of a combination of heat treatment parameters. Originality/value: This paper presents the impact of the aging temperature on diffusion in the alloyed copper CuCr0.7, CuFe2 and CuTi4.

3

Kinetics of precipitation and recrystallisation of titanium copper

Konieczny J., Labisz K., Rdzawski Z., Polok-Rubiniec M., Włodarczyk-Fligier A.

Journal of Achievements in Materials and Manufacturing Engineering

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2014

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Vol. 67, nr 2

53--57

EN

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) relationship, the energy of the nucleation activation, precipitations, and growth of new particles during the ageing, was calculated for two treatment variants. Practical implications: It was found that the activation energy of nucleation of crystal nuclei is lower for the alloy treated according to variant 1st (supersaturation, ageing), while the activation energy of the precipitation and grain growth is lower for the alloy treated according to variant 2nd (supersaturation, cold working Z=50%, ageing). Originality/value: Article presented 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, based on the results of measurement of electrical conductivity.

4

Research on Technology of Alloyed Copper Casting

Rzadkosz S., Kranc M., Garbacz-Klempka A., Piękoś M., Kozana J., Cieślak W.

Archives of Foundry Engineering

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2014

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Vol. 14, iss. 2

79--84

EN

The work presents experiment results from the area of copper casting technology and chosen examples of alloyed copper. At present, copper casting technology is applied in many branches of industrial manufacturing, especially in the sector of construction, communications, arms and power engineering. Alloyed copper, containing slight additions of different elements and having special physio-chemical properties, is used in a special range of applications. Copper technology and alloyed copper analyses have been presented, these materials being used for cast manufacturing for power engineering. The quality of casts has been assessed, based on their microstructure analysis, chemical content and the cast properties. During the research, special deoxidizing and modifying agents were applied for copper and chosen examples of alloyed copper; also exemplary samples were tested with the help of metallographic analysis, electrical conductivity and gaseous impurities research.

5

Application of the artificial neural networks for prediction of hardness of alloyed copper

Konieczny J.

Journal of Achievements in Materials and Manufacturing Engineering

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2012

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Vol. 55, nr 2

529--535

EN

Purpose: The aim of the work is to employ the artificial neural networks for prediction of hardness of the alloyed copper like CuTi, CuFe, CuCr and CuNiSi. Design/methodology/approach: It has been assumed that the artificial neural networks can be used to assign the relationship between the chemical compositions of alloyed copper, temperature and time of solution heat treatment, degree of cold working deformation and temperature and time of ageing. In order to determine the relationship it has been necessary to work out a suitable calculation model. It has been proved that employment of genetic algorithm to selection of input neurons can be very useful tool to improve artificial neural network calculation results. The attempt to use the artificial neural networks for predicting the effect of the chemical composition and parameters of heat treatment and cold working deformation degree on the hardness succeeded, as the level of the obtained results was acceptable. Findings: Artificial neural networks, can be applied for predicting the effect of the chemical composition, parameters of heat treatment and cold working deformation degree on the hardness. Research limitations/implications: Worked out model should be used for prediction of hardness only in particular groups of alloyed copper, mostly because of the discontinuous character of input data. Practical implications: The results of research make it possible to calculate with a certain admissible error the hardness value basing on combinations of concentrations of the particular elements, heat treatment parameters and cold working deformation degree. Originality/value: In this paper it has been presented an original trial of prediction of the required hardness of the alloyed copper like CuTi, CuFe, CuCr and CuNiSi.