Effect Of Nitrogen Contents On Crystal Structure And Properties Of TiN And ZrN Films

TiN and ZrN films are the most commonly used hard film materials in industry.Due to their high hardness,strong film and substrate bonding force,good oxidation resistance and corrosion resistance,TiN and ZrN films are widely used in the surface strengthening of industrial tools and molds.At present,the research on TiN and ZrN hard films with different nitrogen content is usually limited to a certain range of fixed nitrogen content change,and the comprehensive investigation and performance characterization are rarely researched.In this study,the magnetron sputtering deposition technology with central cylinder target was adopted.With high speed steel as the substrate,Ti target and Zr target with purity of 99.99% were selected and the nitrogen content in the film was changed by adjusting the nitrogen flow rate.Using scanning electron microscope to observe different nitrogen content of TiN and ZrN films' s surface morphology and cross section morphology,using X-ray diffraction analysis the phase composition of TiN and ZrN films,micro hardness tester is used to measure vickers hardness of TiN and ZrN films,scratch tester were used to detect film and substrate bonding force of TiN and ZrN films,using resistance furnace for TiN and ZrN films thermal shock performance in 600?,crack and surface morphology observation using scanning electron microscopy.The experimental results show that the nitrogen content of TiN and ZrN films prepared with different nitrogen flow rates.When the nitrogen flow rates of TiN and ZrN films reach 8sccm and 9sccm respectively,the nitrogen content of the TiN and ZrN films almost does not increase with increasing nitrogen flow rate.The surface of both TiN and ZrN films is very smooth.With the increase of nitrogen content,the columnar crystal structure of the films becomes small and compact.Under the same bias voltage,duty cycle,current and time,the thickness of ZrN films is generally higher than that of TiN films.TiN and ZrN films are composed of Ti+TiN and Zr+ZrN phases,respectively at low nitrogen content.With the increase of nitrogen content,TiN and ZrN phases gradually become the main phases of TiN and ZrN films,and the two films have obvious(111)preferred growth orientation.With the increase of nitrogen content,the hardness and film/substrate bonding force of TiN and ZrN films increased firstly and then decreased.The hardness of TiN and ZrN films was up to 1893.2HV and 2158.7HV respectively,and the film/substrate bonding force of TiN and ZrN films was up to more than 200 N.With the increase of nitrogen content,the thermal shock resistance of TiN and ZrN films is improved at 600?,TiN films can withstand up to 6 thermal shock cycles,and ZrN films can withstand up to 9 thermal shock cycles.Moreover,the thermal shock resistance of ZrN films is better than that of TiN film.