Filters

2018 - 201912020 - 20211

More filters

2022 - 20232
Reset filters

Settings

Publisher: Basel : MDPI × Subject: Adhesion ×

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Improved Adhesion of the DLC Coating Using HiPIMS with Positive Pulses and Plasma Immersion Pretreatment
    (Basel : MDPI, 2021) Gómez, Iñigo; Claver, Adrián; Santiago, José Antonio; Fernandez, Iván; Palacio, Jose Fernandez; Diaz, Cristina; Mändl, Stephan; Garcia, Jose Antonio
    Diamond-like carbon (DLC) coatings are used due to their extraordinary tribomechanical properties, great hardness, high elastic modulus, high wear resistance, low friction coefficient and chemical inertness, which provide them with biocompatibility. Compared to other physical vapor deposition (PVD) coatings of transition nitrides and carbonitrides, DLC has limited adhesion, so it is necessary to develop new techniques to overcome this limitation. This work reports the results of scratch testing for the measurement of adhesion and of tests for wear resistance and nanoindentation in AISI 316L stainless steel coated with a WC:C coating, produced using novel high-power impulse magnetron sputtering (HiPIMS) technology with positive pulses. In addition, the use of a preceding surface modification technique, specifically plasma immersion ion implantation (PIII), was studied with the aim of optimizing the adhesion of the coating. The results show how the coating improved the tribomechanical properties through the use of positive pulse HiPIMS compared to conventional HiPIMS, with an adhesion result that reached critical load values of 48.5 N and a wear coefficient of 3.96 × 10−7 mm3/nm
  • Thumbnail Image
    Item
    Selective Grafting of Polyamines to Polyether Ether Ketone Surface during Molding and Its Use for Chemical Plating
    (Basel : MDPI, 2018) Nagel, Jürgen; Zimmermann, Philipp; Schwarz, Simona; Schlenstedt, Kornelia
    We present a new approach of surface functionalization of polyether ether ketone (PEEK) that is carried out during the molding step. Thin films of polymers with different functional groups were applied to the surface of a mold and brought in close contact with a PEEK melt during injection molding. The surfaces of the produced parts were characterized after solidification. Only those PEEK surfaces that were in contact with polymers bearing primary amino groups exhibited a wettability for water. Obviously, the thin polymer film was grafted to the surface by a chemical reaction initiated by the high melt temperature. The formation of azomethine bonds between PEEK and the polyamine by coupling to the ketone groups was proposed. The other amino groups in the molecule were still in function after the molding process. They adsorbed different anionic molecules and anionic charged nanoparticles from aqueous solutions. The surfaces could be chemically plated by copper and nickel with high adhesion.