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Present paper deals with modelling, production and characterization of HVOF PVD (WC-Co and TiN or CrN, respectively) duplex coatings deposited on Ti-6Al-4V substrate for application in automotive industry. As a preliminary analysis, an analytical study of the contact stress distribution under spherical indenter in both coated and uncoated systems, and a finite element evaluation of residual stresses were performed: results showed that the presence of an interlayer with intermediate hardness and stiffness (such as the WC-Co coating) plays a fundamental role in the improvement of the load carrying capacity. Starting from the results of simulations, morphological and compositional characterization of the coatings were performed using SEM and AFM techniques. Mechanical properties were investigated by micro indentation techniques and composite hardness modelling; toughness of the system was qualitatively analysed by Rockwell C indentation. Wear rate of the coatings was measured by an implemented rotating wheel method. Results show higher superficial composite hardness, toughness, adhesion and lower wear rate, in comparison with the simple monolayer system. (c) 2005 Elsevier B.V. All rights reserved.

Nanometrology refers to measurement techniques that assess materials properties at the nanoscale. Laboratory-based characterisation of nanomaterials has been the key enabler in the growth of nanotechnology and nano-enabled products. Due to the small size involved, dimensional measurements has dominated such characterisation underpinned by a tremendous development in stand-alone electron/ion microscopes and scanning probe microscopes.However, the scope of nanometrology extends far beyond off-site, laboratory-based measurements of dimensions only, and is expected to have a tremendous impact on design of nano-enabled materials and devices.In this article, we discuss some of the available techniques for laboratory-based characterisation of mechanical and interfacial properties for nanometrology. We also provide a deep insight into the emerging techniques in measuring these properties, keeping in view the need in advanced manufacturing and nanobio-interactions to develop multifunctional instrumentation, traceable and standardized methods, and modelling tools for unambiguous data interpretation.We also discuss the evaluation of nanomechanical properties and surface/interface response of materials, within the purview of manufacturing processes and standardization.Finally, we discuss scientific and technological challenges that are required to move towards real-time nano-characterisation for rapid, reliable, repeatable and predictive metrology to underpin upscaling nanomaterials and nano-enabled products from the research field to industry and market. Keywords: Nanometrology, Nanoindentation, AFM, Bio, Microscopy, Nanoscopy

This article reports the design, construction, and first use of an experimental device consisting of a specially designed vacuum chamber equipped with a reactive sputtering magnetron (RSM) to be used for controlled deposition of thin films on a Si(100) flat substrate. The setup was designed to allow for in situ and real-time recordings of X-ray diffraction patterns during the growth of the deposited films and was installed in the X-ray diffraction and spectroscopy beamline emerging from a superconducting wiggler source at the Brazilian Synchrotron Light Laboratory. The first use of the RSM setup was an in situ and real-time X-ray diffraction study of processes of growth of multilayered aluminum nitride thin films, whereas the operation parameters of the reactor were sequentially changed. This sequential process led to the development of multilayered films. Alternate variations in chamber pressure and magnetron power density allowed us to obtain thin films composed of several micrometer thick layers, with alternate amorphous and (10·0), (00·2), or (10·1) textured polycrystalline structures.

The microstructural features of TiO2 coatings, deposited by High Velocity Suspension Flame Spraying (HVSFS) from a suspension of titania nanoparticles, were investigated by Focused Ion Beam (FIB) + Scanning Electron Microscopy (SEM) techniques, by Transmission Electron Microscopy (TEM) and by micro-Raman spectroscopy, and were compared to those of conventional HVOF-sprayed TiO2. Proper selection of the HVSFS deposition parameters results in coatings consisting of a dense matrix, made up by the efficient superposition of well-flattened micrometric lamellae, with homogeneously distributed porosity containing sub-micrometric re-solidified spherical particles. Unlike conventional HVOF coatings, lamella boundaries are hardly discernible, no intralamellar cracking occurs and equiaxed crystals appear instead of columnar ones. A homogeneous distribution of anatase and rutile is also found. Modifications to the spray parameters can give rise to large, unmelted agglomerates, scattered throughout the coating and having poor cohesion to the surrounding material. These agglomerates retain the original phase composition of the nanopowder. (C) 2010 Elsevier B.V. All rights reserved.

It is well known that the recrystallization texture of heavily cold-rolled pure copper is almost completely cubic. However, one of the main drawbacks concerning the use of pure copper cube-textured substrates for YBCO coated conductor is the reduced secondary recrystallization temperature. The onset of secondary recrystallization (i.e., the occurrence of abnormal grains with unpredictable orientation) in pure copper substrate was observed within the typical temperature range required for buffer layer and YBCO processing (600-850 °C). To avoid the formation of abnormal grains the effect of both grain size adjustment (GSA) and recrystallization annealing was analyzed. The combined use of a small initial grain size and a recrystallization two-step annealing (TSA) drastically reduced the presence of abnormal grains in pure copper tapes. Another way to overcome the limitation imposed by the formation of abnormal grains is to deposit a buffer layer at temperatures where secondary recrystallization does not occur. For example, La2Zr2O7 (LZO) film with a high degree of epitaxy was grown by metal-organic decomposition (MOD) at 1000 °C on pure copper substrate. In several samples the substrate underwent secondary recrystallization. Our experiments indicate that the motion of grain boundaries occurring during secondary recrystallization process does not affect the quality of LZO film.