Characteristics of TiN and NCD Layers Deposited on Magnesium Alloys

Abstract

Magnesium alloys have been widely used in numerous branches of industry in which reduced mass is of great importance. These alloys are used in aeronautic, astronautic, electronic and sporting goods industries etc. The growing significance of the material magnesium is also closely associated with the progressive development in the field of automotive lightweight construction. The most captivating advantages of magnesium alloys include: the high ratio of mechanical durability to their mass, an excellent heat conductivity, low heat expansion, good casting properties, high functional integrity enabling manufacturing of goods with near-net-shape and good machinability. Magnesium alloys display also some disadvantages, like first of all, the high susceptibility to corrosion, low wear resistance and reduced durability. These disadvantages considerably limit applications of magnesium alloys in industry. The presented work demonstrates the method of deposition of special TiN (Titanium Nitride) and NCD (Nanocrystalline Diamond) layers on the surface of AZ31 magnesium alloys which eliminates these disadvantages. Besides, such layers play both the protective and decorative roles. TiN layers have been deposited by Plasma Activated Physical Vapour Deposition method (PAPVD) in ECAM-France and NCD layers by Plasma Activated Chemical Vapour Deposition method (PACVD) in the Institute of Material Science at the Technical University of Lodz-Poland. This paper shows the method of identification of manufactured layers and investigation results of tribological properties of these layers. Also samples preparation using grinding and polishing method before manufacturing of protective TiN and NCD layers has been depicted.