The Experts below are selected from a list of 222 Experts worldwide ranked by ideXlab platform

Tomasz Moskalewicz - One of the best experts on this subject based on the ideXlab platform.

  • The Effect of the Polymer Structure in Composite Alumina/Polyetheretherketone Coatings on Corrosion Resistance, Micro-mechanical and Tribological Properties of the Ti-6Al-4V Alloy
    Journal of Materials Engineering and Performance, 2019
    Co-Authors: Tomasz Moskalewicz, Aleksandra Fiołek, Alicja Łukaszczyk, Beata Dubiel, Sławomir Zimowski, Łukasz Cieniek
    Abstract:

    This paper describes ways of improving the tribological properties of the Ti-6Al-4V titanium alloy at room and elevated temperatures by electrophoretic deposition of Al_2O_3/PEEK708 composite Coatings and post-heat treatment. The microstructure of the Coating components and the Coatings was examined by scanning and transmission electron microscopy as well as x-ray diffractometry. The influence of cooling rate after heating of the coated alloy on the PEEK structure and Coating surface topography was investigated. It was found that slow cooling with a furnace produced a semi-Crystalline structure, whereas fast cooling in water generated an amorphous polymer structure. The semi-Crystalline Coatings exhibited a more developed surface topography than the amorphous ones. The Coatings with a semi-Crystalline structure revealed higher scratch resistance than the amorphous ones. The corrosion resistance of the uncoated and coated specimens was examined using electrochemical techniques in a 3.5 wt.% NaCl aqueous solution. Both Coatings increased the corrosion resistance of the alloy. The friction and wear properties of the coated specimens against an alumina ball in dry sliding contact at room temperature and elevated temperatures of 150 and 260 °C at ball-on-disk were examined. Both amorphous and semi-Crystalline Coatings increased the wear resistance and decreased the friction coefficient of the titanium alloy at room temperature. In addition, the semi-Crystalline Coating was also very effective in improving the titanium alloy’s tribological properties at elevated temperatures. The obtained results clearly show that the composite alumina/PEEK Coatings are promising for tribological applications in mechanical engineering.

  • The influence of heat treatment on the microstructure, surface topography and selected properties of PEEK Coatings electrophoretically deposited on the Ti-6Al-4V alloy
    Progress in Organic Coatings, 2019
    Co-Authors: Adam Kruk, Łukasz Cieniek, Alicja Łukaszczyk, Sławomir Zimowski, Tomasz Moskalewicz
    Abstract:

    Abstract The aim of this work was to fabricate high temperature PEEK 708 Coatings on the Ti-6Al-4V alloy substrate using electrophoretic deposition and post-deposition heat treatment, as well as to determine the influence of the heat treatment process on the structure, microstructure, surface topography and selected properties of the coated alloy. The design of the EPD parameters (voltage and time) enabled the deposition of homogeneous Coatings. The heat treatment of the as-deposited Coatings, carried out above the polymer melting point, changed the polymer morphology from a granular Coating into a dense and continuous one. Depending on the cooling rate, the Coating exhibited an amorphous or semi-Crystalline structure. The semi-Crystalline Coating consisted of numerous spherulites and had a well-developed surface topography. In contrast, the amorphous Coatings were smooth, with lines consisting of individual crystallites. The polymer structure and microstructure significantly influenced the micromechanical properties and scratch resistance of the Coatings. Semi-Crystalline Coatings had higher hardness and Young's modulus as well as better scratch resistance. Tribological properties were investigated using ball-on-disc tests in dry sliding contact with an alumina ball at room temperature and at elevated temperatures, i.e. 150 °C and 260 °C. It was found that the semi-Crystalline Coatings showed a significantly higher wear resistance and lower coefficient of friction at all the investigated temperatures compared to the amorphous Coatings. The resistance to motion and the wear of the Coatings increased with the ambient temperature of the friction pair. Electrochemical studies showed that both Coatings improved the Ti-6Al-4V alloy's corrosion resistance in a NaCl solution. The improvement was more significant in the case of amorphous Coatings.

Jean-manuel Péan - One of the best experts on this subject based on the ideXlab platform.

  • Comparative static curing versus dynamic curing on tablet Coating structures
    International Journal of Pharmaceutics, 2013
    Co-Authors: Claire Gendre, Olivier Lecoq, Mathieu Boiret, Arafat Tfayli, Pierre Chaminade, Michel Baron, Muriel Genty, Barbara Fayard, Jean-manuel Péan
    Abstract:

    Curing is generally required to stabilize film Coating from aqueous polymer dispersion. This post-Coating drying step is traditionally carried out in static conditions, requiring the transfer of solid dosage forms to an oven. But, curing operation performed directly inside the Coating equipment stands for an attractive industrial application. Recently, the use of various advanced physico-chemical characterization techniques i.e., X-ray micro-computed tomography, vibrational spectroscopies (near infrared and Raman) and X-ray microdiffraction, allowed new insights into the film-Coating structures of dynamically cured tablets. Dynamic curing end-point was efficiently determined after 4 h. The aim of the present work was to elucidate the influence of curing conditions on film-Coating structures. Results demonstrated that 24 h of static curing and 4 h of dynamic curing, both performed at 60 degrees C and ambient relative humidity, led to similar Coating layers in terms of drug release properties, porosity, water content, structural rearrangement of polymer chains and Crystalline distribution. Furthermore, X-ray microdiffraction measurements pointed out different Crystalline Coating compositions depending on sample storage time. An aging mechanism might have occur during storage, resulting in the crystallization and the upward migration of cetyl alcohol, coupled to the downward migration of Crystalline sodium lauryl sulfate within the Coating layer. Interestingly, this new study clearly provided further knowledge into film-Coating structures after a curing step and confirmed that curing operation could be performed in dynamic conditions. (C) 2013 Elsevier B.V. All rights reserved.

  • Comparative static curing versus dynamic curing on tablet Coating structures
    International Journal of Pharmaceutics, 2013
    Co-Authors: Claire Gendre, Olivier Lecoq, Mathieu Boiret, Arafat Tfayli, Pierre Chaminade, Michel Baron, Muriel Genty, Barbara Fayard, Jean-manuel Péan
    Abstract:

    Curing is generally required to stabilize film Coating from aqueous polymer dispersion. This post-Coating drying step is traditionally carried out in static conditions, requiring the transfer of solid dosage forms to an oven. But, curing operation performed directly inside the Coating equipment stands for an attractive industrial application. Recently, the use of various advanced physico-chemical characterization techniques i.e., X-ray micro-computed tomography, vibrational spectroscopies (near infrared and Raman) and X-ray microdiffraction, allowed new insights into the film-Coating structures of dynamically cured tablets. Dynamic curing end-point was efficiently determined after 4 h. The aim of the present work was to elucidate the influence of curing conditions on film-Coating structures. Results demonstrated that 24 h of static curing and 4 h of dynamic curing, both performed at 60 degrees C and ambient relative humidity, led to similar Coating layers in terms of drug release properties, porosity, water content, structural rearrangement of polymer chains and Crystalline distribution. Furthermore, X-ray microdiffraction measurements pointed out different Crystalline Coating compositions depending on sample storage time. An aging mechanism might have occur during storage, resulting in the crystallization and the upward migration of cetyl alcohol, coupled to the downward migration of Crystalline sodium lauryl sulfate within the Coating layer. Interestingly, this new study clearly provided further knowledge into film-Coating structures after a curing step and confirmed that curing operation could be performed in dynamic conditions.

Łukasz Cieniek - One of the best experts on this subject based on the ideXlab platform.

  • The Effect of the Polymer Structure in Composite Alumina/Polyetheretherketone Coatings on Corrosion Resistance, Micro-mechanical and Tribological Properties of the Ti-6Al-4V Alloy
    Journal of Materials Engineering and Performance, 2019
    Co-Authors: Tomasz Moskalewicz, Aleksandra Fiołek, Alicja Łukaszczyk, Beata Dubiel, Sławomir Zimowski, Łukasz Cieniek
    Abstract:

    This paper describes ways of improving the tribological properties of the Ti-6Al-4V titanium alloy at room and elevated temperatures by electrophoretic deposition of Al_2O_3/PEEK708 composite Coatings and post-heat treatment. The microstructure of the Coating components and the Coatings was examined by scanning and transmission electron microscopy as well as x-ray diffractometry. The influence of cooling rate after heating of the coated alloy on the PEEK structure and Coating surface topography was investigated. It was found that slow cooling with a furnace produced a semi-Crystalline structure, whereas fast cooling in water generated an amorphous polymer structure. The semi-Crystalline Coatings exhibited a more developed surface topography than the amorphous ones. The Coatings with a semi-Crystalline structure revealed higher scratch resistance than the amorphous ones. The corrosion resistance of the uncoated and coated specimens was examined using electrochemical techniques in a 3.5 wt.% NaCl aqueous solution. Both Coatings increased the corrosion resistance of the alloy. The friction and wear properties of the coated specimens against an alumina ball in dry sliding contact at room temperature and elevated temperatures of 150 and 260 °C at ball-on-disk were examined. Both amorphous and semi-Crystalline Coatings increased the wear resistance and decreased the friction coefficient of the titanium alloy at room temperature. In addition, the semi-Crystalline Coating was also very effective in improving the titanium alloy’s tribological properties at elevated temperatures. The obtained results clearly show that the composite alumina/PEEK Coatings are promising for tribological applications in mechanical engineering.

  • The influence of heat treatment on the microstructure, surface topography and selected properties of PEEK Coatings electrophoretically deposited on the Ti-6Al-4V alloy
    Progress in Organic Coatings, 2019
    Co-Authors: Adam Kruk, Łukasz Cieniek, Alicja Łukaszczyk, Sławomir Zimowski, Tomasz Moskalewicz
    Abstract:

    Abstract The aim of this work was to fabricate high temperature PEEK 708 Coatings on the Ti-6Al-4V alloy substrate using electrophoretic deposition and post-deposition heat treatment, as well as to determine the influence of the heat treatment process on the structure, microstructure, surface topography and selected properties of the coated alloy. The design of the EPD parameters (voltage and time) enabled the deposition of homogeneous Coatings. The heat treatment of the as-deposited Coatings, carried out above the polymer melting point, changed the polymer morphology from a granular Coating into a dense and continuous one. Depending on the cooling rate, the Coating exhibited an amorphous or semi-Crystalline structure. The semi-Crystalline Coating consisted of numerous spherulites and had a well-developed surface topography. In contrast, the amorphous Coatings were smooth, with lines consisting of individual crystallites. The polymer structure and microstructure significantly influenced the micromechanical properties and scratch resistance of the Coatings. Semi-Crystalline Coatings had higher hardness and Young's modulus as well as better scratch resistance. Tribological properties were investigated using ball-on-disc tests in dry sliding contact with an alumina ball at room temperature and at elevated temperatures, i.e. 150 °C and 260 °C. It was found that the semi-Crystalline Coatings showed a significantly higher wear resistance and lower coefficient of friction at all the investigated temperatures compared to the amorphous Coatings. The resistance to motion and the wear of the Coatings increased with the ambient temperature of the friction pair. Electrochemical studies showed that both Coatings improved the Ti-6Al-4V alloy's corrosion resistance in a NaCl solution. The improvement was more significant in the case of amorphous Coatings.

Claire Gendre - One of the best experts on this subject based on the ideXlab platform.

  • Comparative static curing versus dynamic curing on tablet Coating structures
    International Journal of Pharmaceutics, 2013
    Co-Authors: Claire Gendre, Olivier Lecoq, Mathieu Boiret, Arafat Tfayli, Pierre Chaminade, Michel Baron, Muriel Genty, Barbara Fayard, Jean-manuel Péan
    Abstract:

    Curing is generally required to stabilize film Coating from aqueous polymer dispersion. This post-Coating drying step is traditionally carried out in static conditions, requiring the transfer of solid dosage forms to an oven. But, curing operation performed directly inside the Coating equipment stands for an attractive industrial application. Recently, the use of various advanced physico-chemical characterization techniques i.e., X-ray micro-computed tomography, vibrational spectroscopies (near infrared and Raman) and X-ray microdiffraction, allowed new insights into the film-Coating structures of dynamically cured tablets. Dynamic curing end-point was efficiently determined after 4 h. The aim of the present work was to elucidate the influence of curing conditions on film-Coating structures. Results demonstrated that 24 h of static curing and 4 h of dynamic curing, both performed at 60 degrees C and ambient relative humidity, led to similar Coating layers in terms of drug release properties, porosity, water content, structural rearrangement of polymer chains and Crystalline distribution. Furthermore, X-ray microdiffraction measurements pointed out different Crystalline Coating compositions depending on sample storage time. An aging mechanism might have occur during storage, resulting in the crystallization and the upward migration of cetyl alcohol, coupled to the downward migration of Crystalline sodium lauryl sulfate within the Coating layer. Interestingly, this new study clearly provided further knowledge into film-Coating structures after a curing step and confirmed that curing operation could be performed in dynamic conditions. (C) 2013 Elsevier B.V. All rights reserved.

  • Comparative static curing versus dynamic curing on tablet Coating structures
    International Journal of Pharmaceutics, 2013
    Co-Authors: Claire Gendre, Olivier Lecoq, Mathieu Boiret, Arafat Tfayli, Pierre Chaminade, Michel Baron, Muriel Genty, Barbara Fayard, Jean-manuel Péan
    Abstract:

    Curing is generally required to stabilize film Coating from aqueous polymer dispersion. This post-Coating drying step is traditionally carried out in static conditions, requiring the transfer of solid dosage forms to an oven. But, curing operation performed directly inside the Coating equipment stands for an attractive industrial application. Recently, the use of various advanced physico-chemical characterization techniques i.e., X-ray micro-computed tomography, vibrational spectroscopies (near infrared and Raman) and X-ray microdiffraction, allowed new insights into the film-Coating structures of dynamically cured tablets. Dynamic curing end-point was efficiently determined after 4 h. The aim of the present work was to elucidate the influence of curing conditions on film-Coating structures. Results demonstrated that 24 h of static curing and 4 h of dynamic curing, both performed at 60 degrees C and ambient relative humidity, led to similar Coating layers in terms of drug release properties, porosity, water content, structural rearrangement of polymer chains and Crystalline distribution. Furthermore, X-ray microdiffraction measurements pointed out different Crystalline Coating compositions depending on sample storage time. An aging mechanism might have occur during storage, resulting in the crystallization and the upward migration of cetyl alcohol, coupled to the downward migration of Crystalline sodium lauryl sulfate within the Coating layer. Interestingly, this new study clearly provided further knowledge into film-Coating structures after a curing step and confirmed that curing operation could be performed in dynamic conditions.

Alicja Łukaszczyk - One of the best experts on this subject based on the ideXlab platform.

  • The Effect of the Polymer Structure in Composite Alumina/Polyetheretherketone Coatings on Corrosion Resistance, Micro-mechanical and Tribological Properties of the Ti-6Al-4V Alloy
    Journal of Materials Engineering and Performance, 2019
    Co-Authors: Tomasz Moskalewicz, Aleksandra Fiołek, Alicja Łukaszczyk, Beata Dubiel, Sławomir Zimowski, Łukasz Cieniek
    Abstract:

    This paper describes ways of improving the tribological properties of the Ti-6Al-4V titanium alloy at room and elevated temperatures by electrophoretic deposition of Al_2O_3/PEEK708 composite Coatings and post-heat treatment. The microstructure of the Coating components and the Coatings was examined by scanning and transmission electron microscopy as well as x-ray diffractometry. The influence of cooling rate after heating of the coated alloy on the PEEK structure and Coating surface topography was investigated. It was found that slow cooling with a furnace produced a semi-Crystalline structure, whereas fast cooling in water generated an amorphous polymer structure. The semi-Crystalline Coatings exhibited a more developed surface topography than the amorphous ones. The Coatings with a semi-Crystalline structure revealed higher scratch resistance than the amorphous ones. The corrosion resistance of the uncoated and coated specimens was examined using electrochemical techniques in a 3.5 wt.% NaCl aqueous solution. Both Coatings increased the corrosion resistance of the alloy. The friction and wear properties of the coated specimens against an alumina ball in dry sliding contact at room temperature and elevated temperatures of 150 and 260 °C at ball-on-disk were examined. Both amorphous and semi-Crystalline Coatings increased the wear resistance and decreased the friction coefficient of the titanium alloy at room temperature. In addition, the semi-Crystalline Coating was also very effective in improving the titanium alloy’s tribological properties at elevated temperatures. The obtained results clearly show that the composite alumina/PEEK Coatings are promising for tribological applications in mechanical engineering.

  • The influence of heat treatment on the microstructure, surface topography and selected properties of PEEK Coatings electrophoretically deposited on the Ti-6Al-4V alloy
    Progress in Organic Coatings, 2019
    Co-Authors: Adam Kruk, Łukasz Cieniek, Alicja Łukaszczyk, Sławomir Zimowski, Tomasz Moskalewicz
    Abstract:

    Abstract The aim of this work was to fabricate high temperature PEEK 708 Coatings on the Ti-6Al-4V alloy substrate using electrophoretic deposition and post-deposition heat treatment, as well as to determine the influence of the heat treatment process on the structure, microstructure, surface topography and selected properties of the coated alloy. The design of the EPD parameters (voltage and time) enabled the deposition of homogeneous Coatings. The heat treatment of the as-deposited Coatings, carried out above the polymer melting point, changed the polymer morphology from a granular Coating into a dense and continuous one. Depending on the cooling rate, the Coating exhibited an amorphous or semi-Crystalline structure. The semi-Crystalline Coating consisted of numerous spherulites and had a well-developed surface topography. In contrast, the amorphous Coatings were smooth, with lines consisting of individual crystallites. The polymer structure and microstructure significantly influenced the micromechanical properties and scratch resistance of the Coatings. Semi-Crystalline Coatings had higher hardness and Young's modulus as well as better scratch resistance. Tribological properties were investigated using ball-on-disc tests in dry sliding contact with an alumina ball at room temperature and at elevated temperatures, i.e. 150 °C and 260 °C. It was found that the semi-Crystalline Coatings showed a significantly higher wear resistance and lower coefficient of friction at all the investigated temperatures compared to the amorphous Coatings. The resistance to motion and the wear of the Coatings increased with the ambient temperature of the friction pair. Electrochemical studies showed that both Coatings improved the Ti-6Al-4V alloy's corrosion resistance in a NaCl solution. The improvement was more significant in the case of amorphous Coatings.