from the conferences organized by TANGER Ltd.
A characteristic feature of the beam technologies is that the treatment of materials occurs as a result of the impact of the concentrated energy flux. By controlling the energy flux, the selected areas of the surface can undergo the treatment process. The diameter of the energy beam varies from a fraction of nanometers to several tens of centimeters. It depends on the basic physical phenomenon occurring in a given technology. The smallest field of impact is typical of the methods which use a stream of electrons or a laser beam. The energy streams, occurring here, are focused and controlled by optical or magnetic lens systems or mirrors, while the size of the spot in the focal point depends only on the wavelength of the electron or laser radiation. There are many methods for producing surface coatings, such as electroplating and plasma spraying. The use of laser treatment to improve the properties of electro-spark coatings is very interesting. The main objective of the present work is to determine the effects of laser treatment on properties of WC-Co coatings electro-spark deposited (ESD) on steel substrates. The microstructure and properties of laser treated/melted coatings were evaluated by means of: scanning electron (SEM) microscopy, X-ray diffraction (XRD), surface roughness measurements, hardness and corrosion resistance tests. The obtained experimental data show that the laser-treated ESD WC-Co coatings are characterised by lower hardness, higher resistance to seizure and roughness, and better adhesion to the substrate. The laser treatment homogenizes the chemical composition, refines the microstructure and heals microcracks and pores of ESD coatings. The laser treated ESD WC-Co coatings can be used in sliding friction pairs and as protective layers.
Keywords: Electro-spark coatings, laser treatment, properties© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.