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Effect of heat treatment on micro structural changes in aluminium bronze

Hájek J., Křiž A., Chocholaty O., Pakuła D.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 3

1271--1276

EN

Effect of heat treatment on micro structural changes in aluminium bronze This paper attempts to summarise the niicrostructural changes which take place in aluniiniuni bronzes during heat treatment. Another objective of this study was to map the potential of a certain type of aluminium bronzes for undergoing martensitic transformation. The methods, which were chosen for assessing the results of heat treatment with regard to their availability, included measurement of hardness and observation of inicrostructure using light and scanning electron microscopy. Additional tools for evaluation of microstructure comprised measurement of microhardness and chemical analysis by EDS. An important part of the experiment is observation of microstructural changes in the Joniiny bar during the end-quench test. Upon completing experiments of this kind, one can define the heat treatment conditions necessary for obtaining optimum properties. In addition, the paper presents important findings on how to improve the corrosion resistance of aluminium bronzes by special heat treatment sequences.

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Investigation of PVD coatings deposited on the Si3N4 and sialon tool ceramics

Pakuła D., Dobrzański L., Křiž A., Staszuk M.

Archives of Materials Science and Engineering

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2010

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Vol. 46, nr 1

53-60

EN

Purpose: The paper presents investigation results of the structure and properties of the coatings deposited by cathodic arc evaporation - physical vapour deposition (CAE-PVD) techniques on the Si3N4 and sialon tool ceramics. The Ti(B,N), Ti(C,N), (Ti,Zr)N and (Ti,Al)N coatings were investigated. Design/methodology/approach: The structural investigation includes the metallographic analysis on the scanning electron microscope. Examinations of the chemical compositions of the deposited coatings were carried out using the X-ray energy dispersive spectrograph EDS and using the X-ray diffractometer. The investigation includes also analysis of the mechanical and functional properties of the material: microhardness tests of the deposited coatings, surface roughness tests, evaluation of the adhesion of the deposited coatings. Findings: Deposition of the multicomponent gradient coatings with the PVD method, based on the B, Al and Zr solid secondary solution in the TiN titanium nitride, isomorphous with the alternating pure titanium nitride TiN, on tools made from nitride ceramics and sialon's ceramics, results in the increase of mechanical properties in comparison with uncoated tool materials, deciding thus the improvement of their working properties. Research limitations/implications: Ti(B,N), Ti(C,N), (Ti,Zr)N and (Ti,Al)N multicomponent and gradient coatings can be applied for cutting ceramic tools. Originality/value: Comparison of the wide

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Structure and mechanical properties of PVD gradient coatings deposited onto tool steels and sialon tool ceramics

Dobrzański L. A., Staszuk M., Křiž A., Lukaszkowicz K.

Journal of Achievements in Materials and Manufacturing Engineering

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2009

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Vol. 37, nr 1

36-43

EN

Purpose: The paper presents investigation results of the structure and mechanical properties of gradient coatings deposited by cathodic arc evaporation - physical vapour deposition (CAE-PVD) techniques onto the X40CrMoV5-1 hot work tool steel, HS6-5-2 high speed steel and SiAlON tool ceramics. The Ti(C,N), (Ti,Al)N and (Al,Si,Cr) N coatings were investigated. Design/methodology/approach: Microstructure was characterised using scanning and transmission electron microscopy. The phase composition of the investigated coatings was determined by means of the X-ray diffractometer. The chemical concentration changes of the coating components, and the substrate material were evaluated in virtue of tests carried out in the GDOS spectrometer. Tests of the coatings’ adhesion to the substrate material were made using the scratch test method. Findings: It was found out that the structure of the PVD coatings deposited onto all substrates is composed of fine crystallites. The investigations made by use of the glow discharge optical emission spectrometer indicate to the existence of the transition zone between the substrate material and the coating. The results show that all coatings present good adhesion. The critical load LC2, which is in the range 35-90 N, depends on the coating type and substrate. Good adhesion of the coatings deposited to the substrate should be connected with the existence of the transition zone. All the coatings are demonstrated by high hardness. Research limitations/implications: Ti(C,N), (Ti,Al)N and (Al,Si,Cr) N gradient coatings can be applied for cutting tools and hot working tools. Originality/value: Working out and testing PVD coatings obtained by tool ceramic and tool steels is a special future of development direction in a domain of thin coatings.

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Influence of the PVD and CVD technologies on the residual macrostresses and functional properties of the coated tool ceramics

Dobrzański L. A., Skrzypek S., Pakuła D., Mikuła J., Křiž A.

Journal of Achievements in Materials and Manufacturing Engineering

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2009

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Vol. 35, nr 2

162-168

EN

Purpose: The goal of this work is to compare the macro-stresses as well as mechanical and functional properties of the PVD and CVD coatings deposited on oxide and nitride ceramics tool. Design/methodology/approach: In the paper the residual macro-stresses of PVD and CVD coatings deposited on tool ceramics substrates, measured with the application of the grazing angle X-ray diffraction geometry are compared in relation to the fundamental mechanical properties like hardness and adhesion. Findings: Basing on the tribological test made by the use of the „pin-on-disk” method, the influence of the residual macro-stresses to wear resistance is being investigated. Practical implications: The process of covering tools with the thin wear resistant PVD and CVD coatings is currently the most commonly method used to extend their life. Investigations of those coatings determining their mechanical properties, chemical composition, and structure, enable to pick out the optimum coatings for given industrial applications. Originality/value: New X-ray diffraction g-sin2ř method based on glancing angle X-ray beam geometry (GID), macro-stresses of the examined CVD and PVD coatings have been measured.