Texture control of sputter-deposited nitride films has provoked a great deal of interest due to its technological importance. Despite extensive research, however, the reported results are scattered and discussions about the origin of preferred orientation (PO) are sometimes conflicting, and therefore controversial. The aim of this study is to acquire a clear perspective in order to discuss the origin of PO of sputter-deposited nitrides. Among nitrides, we focus on titanium nitride (TiN), aluminum nitride (AlN), and tantalum nitride (TaN), which are three commonly used nitrides. First, we collected reported experimental results about the relation between operating conditions and PO, because PO is considered to be determined by film formation processes, such as surface diffusion or grain growth, which is affected by operating conditions. We also collected reported results about such PO-determining processes. Then, we categorized the PO-determining processes into an initial stage and a growth stage of film d...

Comprehensive perspective on the mechanism of preferred orientation in reactive-sputter-deposited nitrides

Polycrystalline 4 μm and 14 μm thick multilayer TiB2/TiC coatings with varying number of total layers (2–20) were deposited by ion beam assisted, electron beam–physical vapor deposition (IBA, EB–PVD) on WC–6wt%Co–03wt%TaC substrates The average Vicker's hardness numbers were found to increase with increasing total number of layers and ranged from 3215 VHN0050 to 3726 VHN0050 and 3294 VHN0050 to 3991 VHN0050 for the 4 μm and 14 μm thick multilayer TiB2/TiC coatings, respectively The adhesion of the multilayer coatings was found to be greater than 50 N for a 4 μm thick film and less than 30 N for the thicker films The degree of crystallographic texture was found to change with varying total number of layers, as well as the orientation of both materials within the multilayer system The grain size and amount of residual compressive stress was found to decrease with increasing number of layers In addition, the fracture toughness was found to decrease with increasing total number of layers This paper discusses the effect of changing the individual layer thickness (ie total number of layers) for TiC/TiB2 multilayer coatings deposited on WC–6wt%Co–03wt%TaC cutting inserts on the average Vicker's hardness number, adhesion, stress, fracture toughness, argon impurities, average crystallite size, crystallographic texture, surface morphology and microstructure using a variety of characterization techniques

Synthesis and characterization of multilayered TiC/TiB2 coatings deposited by ion beam assisted, electron beam–physical vapor deposition (EB–PVD)

Effect of sputtering target power density on topography and residual stress during growth of nanocomposite nc-TiN/a-SiNx thin films

The structural properties of thin Ti films were studied by x-ray scattering techniques aiming at an improved understanding of residual stress and preferred orientation in thin metal films when subjected to a high ion flux during deposition. The samples were prepared by gas-flow sputtering and by subjecting the substrate to a midfrequency bias during deposition. Large arrival ratios of ions over deposited atoms, Ji∕Ja, could be realized by this processing. Some hundred nanometers thin Ti layers were characterized by x-ray reflectometry, symmetric θ∕2θ diffraction, pole figure analysis, and residual stress measurements by the sin2ψ and by the scattering vector technique, the latter method enabling a depth-resolved determination of stress fields. Whereas the stress state in an unbiased sample turned out to be tensile accompanied by a dominating (00.l) texture component, the biased samples were found to exhibit an overall compressive stress and a (h0.0) fiber texture. The results for the unbiased sample could...

X-ray diffraction study on residual stress and preferred orientation in thin titanium films subjected to a high ion flux during deposition

Fabrication of cost-effective, nano-grained net-shaped components has brought considerable interest to Department of Defense, National Aeronautics and Space Administration, and Department of Energy. The objective of this paper is to demonstrate the versatility of electron beam-physical vapor deposition (EB-PVD) technology in engineering new nanostructured materials with controlled microstructure and microchemistry in the form of coatings and net-shaped components for many applications including the space, turbine, optical, biomedical, and auto industries. Coatings are often applied on components to extent their performance and life under severe environmental conditions including thermal, corrosion, wear, and oxidation. Performance and properties of the coatings depend upon their composition, microstructure, and deposition condition. Simultaneous co-evaporation of multiple ingots of different compositions in the high energy EB-PVD chamber has brought considerable interest in the architecture of functional graded coatings, nano-laminated coatings, and design of new structural materials that could not be produced economically by conventional methods. In addition, high evaporation and condensate rates allowed fabricating precision net-shaped components with nanograined microstructure for various applications. Using EB-PVD, nano-grained rhenium (Re) coatings and net-shaped components with tailored microstructure and properties were fabricated in the form of tubes, plates, and Re-coated spherical graphite cores. This paper will also present the results of various metallic and ceramic coatings including chromium, titanium carbide (TiC), titanium diboride (TiB2), hafnium nitride (HfN), titanium-boron-carbonitride (TiBCN), and partially yttria stabilized zirconia (YSZ) TBC coatings deposited by EB-PVD for various applications.

Nanostructured component fabrication by electron beam-physical vapor deposition

High-fluence nitrogen ion implantation into titanium at room temperature results in the formation of titanium nitride precipitation. Electron diffraction measurements reveal an implantation-induced texture of titanium nitride precipitations. Electron diffraction diagrams were taken while tilting the implanted samples and incomplete pole figures were determined. The measured pole figures show a fibre texture. The reproduction of the orientation distribution function based on a tomographic algorithm. The experiments demonstrate a strong coupling effect of implantation-induced texture on direction of implantation. The most intensive texture component, the (111) plane, is always perpendicular to the direction of implantation. Results of this investigation support the assumption that the effect of implantation-induced texture is caused by the process of seed selection through ion channeling.

B. Rauschenbach

Papers

Implantation-induced texture