Microstructure And Mechanical Properties Of Chromium Nitride Coatings By Arc Ion Plating

Hard coatings are widely used as protective layer for machine parts to improve the appearance and to extent the service life in many different fields. Development for a new protective coating with excellent properties has been drawn a great deal of interest over years. CrN coating is used in tribological applications as a barrier layer due to high hardness, low coefficient, good oxidation-resistance, thermodynamical stability and is considered to be a promising hard coating.The purpose of this work is to study the influence of deposition parameters ( for example Bombard before deposition, bias voltage, N2 partial pressure, arc current ) on the microstructure and the mechanical properties of CrN coating prepared on TC4 substrate by arc ion plating (AIP).The work for enhancing CrN coating quality possesses the important guidance effect.The idiographic work:(1) The influence of ion bombardment on CrN coating It is indicated that the ion bombardment on the substrate due to high bias before deposition plays great role in the surface morphologies and phase structure of CrN coating. The high energy ion bombardment sputters to the base body surface, and removes adsorbent gas and the impurity of surface, and sputters peeling off the oxide of the surface layer, and makes the base body surface roughness increase, and gives rise to many small protruding and small concave holes.In the ion bombardment course, the energy of ion changes to surface heat, causes that the temperature of base body goes up, thus making the macroparticles...