Papers by Keyword: Hard Film

Abstract: A method used to determine the residual stress in a hard film deposited on a soft substrate via the unloading load-depth curves was proposed. The unloading curves with transitional behaviors were used to determine the film deflection stiffness, and then the residual stresses were obtained. Significant extra stresses were induced by a cube corner indenter at large depth. In contrast, the indentation-induced stresses could be neglected in cases of Berkovich indentation at relatively small depths.

Abstract: Surface treatment of hard nitride film with high-intensity pulsed ion beam (HIPIB) was investigated in the present research. On considering the high energy density and short pulse duration of HIPIB source, a one-dimension physical model was built according to the structure feature of film-base sample. It was found that the irradiation of HIPIB lead to a very fast thermal recycle of heating rate 1011K/s and cooling rate up to 1010K/s. The highest temperature located at the surface of film irradiated. When using the HIPIB parameters of accelerating voltage 350kV, pulse duration 70ns and current density 60A/cm2, the surface layer of film would be melt with depth of about 0.35mm, that was verified by the experimental result along with the grain refinement effect due to the fast solidification process.

Abstract: Titanium boron nitride (Ti,B)N films have been prepared by depositing Ti and B atom vapor on a (100) Si single crystal and an amorphous glass substrates under simultaneous irradiation of N ions, that is ion mixing and vapor deposition (IVD) technique. The transport ratio of metals and ion, (Bva+Tiva)/Nion, was fixed at 4, and the film thickness was supposed to be 1
m. With an increase in the evaporation ratio of B and Ti, Bva/Tiva, from 0 to 3, microstructure of the film was changed from fine triangular to granular morphology. It was confirmed by the XPS analysis that N ions were preferentially coordinated with Ti atoms when the Bva/Tiva was relatively low otherwise nitriding of B probably occurred. This result was also supported by the XRD spectra of the films. Knoop hardness of the (Ti,B)N films was strongly dependent on the Bva/Tiva. The highest hardness of approximately 5000 was observed at the Bva/Tiva=0.3; this implies that a small amount of alloying B considerably increases the film hardness.