TiN films were deposited on stainless steel substrates by arc ion plating. The influence of an axial magnetic field was examined with regard to the microstructure, chemical elemental composition, mechanical properties and wear resistance of the films. The results showed that the magnetic field puts much effect on the preferred orientation, chemical composition, hardness and wear resistance of TiN films. The preferred orientation of the TiN films changed from(111) to(220) and finally to the coexistence of(111) and(220) texture with the increase in the applied magnetic field intensity. The concentration of N atoms in the TiN films increases with the magnetic field intensity, and the concentration of Ti atoms shows an opposite trend. At first, the hardness and elastic modulus of the TiN films increase and reach a maximum value at 5 m T and then decrease with the further increase in the magnetic field intensity. The high hardness was related to the N/Ti atomic ratio and to a well-pronounced preferred orientation of the(111) planes in the crystallites of the film parallel to the substrate surface. The wear resistance of the Ti N films was significantly improved with the application of the magnetic field, and the lowest wear rate was obtained at magnetic field intensity of 5 m T. Moreover, the wear resistance of the films was related to the hardness H and the H3/E*2 ratio in the manner that a higher H3/E*2 ratio was conducive to the enhancement of the wear resistance.
The Cr-Mo-N films were deposited on high speed steel(HSS) substrates by a DC reactive magnetron sputtering equipment coupled with two horizontal magnetron sources.The effects of substrate negative bias voltage(V_b),substrate temperature(T_s) and gas flow ratio(R= N_2/(N_2 + Ar)) on the microstructure,morphology,as well as the mechanical and tribological properties of the Cr-Mo-N films were investigated by virtue of X-ray diffraction(XRD) analysis,X-ray photoelectron spectroscopy(XPS),field emission scanning electron microscopy(FESEM),atomic force microscopy(AFM),nano-indentation test,ball-on-disk tribometer,and Rockwell indenter et al.With increasing V_b to-100 V,the preferred orientation of the films changed from(111) to(200) and their mechanical and tribological properties were improved gradually,too.It was also found that T_s gave a significant effect on mechanical property enhancement.When the T_s reached 300 ℃,the film obtained the highest hardness and effective elastic modulus of approximately 30.1 and 420.5 GPa,respectively and its critical load increased to about 54 N.With increasing R,the phase transformation from body-centered-cubic(bcc) Cr and hexagonal CrMoN_x multiphase to single face-centered-cubic(fcc) solid solution phase was observed.The correlations between values of hardness(H),effective elastic modulus(E~*),HIE~*,H^3/E^(*2),elastic recovery(1/14) and tribological properties of the films were also investigated.The results showed that the elastic recovery played an important role in the tribological behavior.
Dongli QiHao LeiTiegang WangZhiliang PeiJun GongChao Sun
