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Possibilities of biocompatible material production using conform SPD technology

Palán J., Maleček L., Hodek J., Zemko M., Dzugan J.

Archives of Materials Science and Engineering

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2017

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Vol. 88, nr 1

5--11

EN

Purpose: At present, materials research in the area of SPD (severe plastic deformation) processes is very intensive. Materials processed by these techniques show better mechanical properties and have finer grain when compared to the input feedstock. The refined microstructure may be ultrafine-grained or nanostructured, where the grain size becomes less than 100 nm. One of the materials used for such processes is CP (commercially pure) titanium of various grades, which is widely used for manufacturing dental implants. The article deals with one of the technologies available for the production of ultrafine-grained titanium: Conform technology. CP titanium processed by CONFORM technology exhibits improved mechanical properties and very favourable biocompatibility, due to its fine-grained structure. The article presents the current experience in the production of ultrafine CP titanium using this technology. The main objective of this article is describing the behaviour of CP titanium during forming in the Conform device and its subsequent use in dental implantology. Design/methodology/approach: In the present study, commercially pure Grade 2 titanium was processed using the CONFORM machine. The numerical simulation of the process was done using FEM method with DEFORMTM software. The evaluation was performed by simple tensile testing and transmission electron microscopy. The first conclusions were derived from the determined mechanical properties and based on analogies in available publications on a similar topic. Findings: This study confirmed that the SPD process improves mechanical properties and does not impair the ductility of the material. The CONFORM process enables the continuous production of ultrafine-grained or nanostructured materials. Research limitations/implications: At the present work, the results show the possible way of continuous production of ultrafine-grained or nanostructured materials. Nevertheless, the further optimization is needed in order to improve the final quality of wires and stabilize the process. As these factors will be solved, the technology will be ready for the industry. Practical implications: The article gives the practical information about the continuous production of ultrafine-grained pure titanium Grade 2 and the possibility of use this material for dental implants. Originality/value: The present paper gives information about the influence of the CONFORM technology on final mechanical and structural properties with the emphasis on technological aspects.

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Impact of rotary swaging and age hardening on mechanical properties of EN AW 2024

Kövér M., Sláma P., Palán J.

Journal of Achievements in Materials and Manufacturing Engineering

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2015

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Vol. 72, nr 2

61--66

EN

Purpose: Invention of severe plastic deformation methods led to increased interest in ultra-fine grained materials. The hardenable aluminium alloys were extensively studied in the last decade. It was revealed that combination of severe plastic deformation and age hardening can significantly improve the material properties of these alloys. In this article we performed such progressive thermo-mechanical treatment and following mechanical testing and metallographic analysis. The aim was to evaluate the influence of this treatment on mechanical properties, mostly the effect of various age hardening temperatures and time. Aluminium alloy EN AW 2024 was chosen for the experimental procedures. Impact of processing parameters on mechanical properties was determined by tensile testing. Metallographic analysis was used for evaluation of the straining influence on grain morphology. In the conclusion we denoted significant strain hardening effect, present shear bands and change in aging kinetics. Design/methodology/approach: The experimental material was processed by progressive thermo-mechanical treatment. The evaluation was performed by simple tensile testing and light microscopy. The first conclusions were derived from determined mechanical properties and based on similarities in available publications with related topic. Findings: The research results roughly confirm the recovery-precipitation complementary effect, observed in other hardenable aluminium alloys or the same hardenable alloy deformed by other SPD technique. The impact of both parts of processing – deformation and age hardening on mechanical properties was evaluated. Research limitations/implications: Future detailed investigation of secondary phase particles and dislocation-precipitate interaction should be performed. This investigation was not performed as it requires transmission electron microscopy. Originality/value: The paper contains first impression on promising SPD technique. As the technique appeared only recently, very few articles were published, considering few light alloys. The paper can help to set parameters for other researchers in this field and promote commercialization of this progressive thermo-mechanical processing

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Mechanical and microstructural properties of Mg-based AZ31 alloy processed by ARB

Palán J., Kubina T., Köver M., Slama P.

Archives of Materials Science and Engineering

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2015

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Vol. 76, nr 2

129--133

EN

Purpose: Severe plastic deformation techniques are known to produce materials with ultrafine-grained structures and enhanced mechanical properties. In magnesium alloys, these techniques improve both strength and ductility, as the latter is normally low at room temperature. In the present experiment, properties of rolled products after two rolling passes were examined. Rolling was carried out at 350°C and 400°C. At 350°C, the rolled sheets did not bond. Mechanical properties of the rolled products were determined. Microhardness profiles were measured to map the deformation distribution. The impact of the number of passes on mechanical properties was evaluated. It was found that with increasing number of passes, ultimate strength yield strength improve, and elongation does not decrease. Metallographic examination of the rolled products was carried out to assess the quality of the resulting joint. In certain locations, the joint was not distinctly visible, which proves its high quality. Design/methodology/approach: The evaluation was performed by simple tensile testing and light microscopy. The first conclusions were derived from the determined mechanical properties and based on analogies in available publications on a similar topic. Findings: This study confirmed that the SPD process improves mechanical properties and does not impair the ductility of the material. With increasing number of passes, the mechanical properties of the sample become more uniform.