Abstract: Advanced TiC/a-C:H nanocomposite coatings have been produced via reactive deposition
in a closed-field unbalanced magnetron sputtering system. In this paper, we report on the
tribological behavior of TiC/a-C:H nanocomposite coatings in which ultra-low friction is tailored
with superior wear resistance, being two properties often difficult to achieve simultaneously. In-situ
monitoring the wear depth at nanometer scale reveals that the self-lubricating effects are induced by
the formation of transfer films on the surface of ball counterpart. In addition, the CoF of TiC/a-C:H
nanocomposite coatings decreases with decreasing relative humidity. This phenomenon can be
interpreted in terms of water molecule interactions with the wear track. The influence of the volume
fraction and grain size of TiC nanocrystallites on the coating properties has been examined. A
superior wear resistance at a level of 10-17 m³/(N m lap) has been achieved under the condition of
super-low friction and high toughness, both of which require fine TiC nano-particles (e.g. 2 nm) and
a wide matrix separation that must be comparable to the dimensions of the nano-particles.
Abstract: In this study, the grain refinement near the surface of metal workpiece using hot shot
peening was investigated to improve the surface properties of the workpiece. In this process, the
grains were refined due to plastic deformation generated by the collision of a lot of shots under hot
working conditions. A model experiment using two shots was carried out to examine the effects of
the amount of deformation, the processing temperature and the time interval of the collision on grain
size. In the experiment, the workpieces were stainless steel SUS304 and commercially pure copper.
It was found that the global surface layer successfully attained to the fine grains by means of hot shot
Abstract: MCrAlY-typed coatings are conventional for applications to land-based turbines against hightemperature
oxidation and corrosion. However, improvements are still currently expected from
innovations in the coating process and/or in the selection of the starting materials. Both types of
innovations were studied in the present work. The former consisted in cold spray as a substitute
for plasma spray which is conventionally used as the coating process. The latter consisted in
developing mechanically-alloyed powders to be suitable for the targeted application especially.
In this study, coating-substrate adhesion was considered as the justice of the peace to assess
improvements from these innovations. This was determined using the LAser Shock Adhesion
Test, namely LASAT, which was recently developed as innovative adhesion testing of thermal
Among the main results, mechanical alloying was shown to be satisfactory to result in an
homogeneous powder from the mixing of CoNiCrAlY with Mo. This powder could be coldsprayed,
all the more easily because of a fine grain size. Results were compared with those
obtained from conventional commercial pre-alloyed powders. As a general result, it was shown
that cold spray could lead to highly-dense and high-adhesion MCrAlY-typed coatings onto
Inconel 625 even though the process is usually claimed to be convenient for high-ductility
materials such as copper. Incidentally, LASAT was confirmed to be a flexible and powerful
testing tool to study adhesion; which resulted in the ranking of the various types of coatings
involved in the work. Results are discussed in the light of an experimental simulation of the
impinging of cold-sprayed particles using so-called “laser flier impact experiments”. In this
development of this simulation approach to cold spray, the flier was made of a 50μm-thick disc
machined from HIP’ed CoNiCrAlY.
Abstract: In this work two different synthesis processes for Single-Wall Carbon Nanotubes
deposition (such as the Hot Filament-Chemical Vapor Deposition, HF-CVD, and the electrophoretic
deposition, EPD) on microwire surfaces, were described. Then, the morphological and structural
characterization of SWNT-modified microwires were performed by Scanning Electron Microscopy
(FE-SEM) and Raman Spectroscopy, respectively. Finally, the nanostrcutured microelectrodes were
electrochemically characterized using NADH, NAD+, epinephrine, and ascorbic acid (AA), useful
biological molecules to develop electrochemical sensors and biosensors.
Abstract: Hot-dip galvanized transformation induced plasticity (TRIP) steel sheets were recently
developed for automotive applications. The microstructure and the adhesion of zinc coated CMnSi
TRIP steel alloyed with P were studied. The α-Zn coating adjacent to the steel substrate consists of a
continuous η-Fe2Al5-xZnx inhibition layer with columnar ζ-FeZn13 intermetallic particles on top.
Along the interface between the inhibition layer and the steel substrate Mn/Mn-P oxides were
frequently observed. Although these oxides at the steel surface reduce the adhesion between the zinc
coating and the TRIP steel, they do not cause any bare spots during galvanizing. Upon tensile
deformation of the galvanized steel sheet, cracking along the α-zinc grain boundaries preceded
fracture of the interface between the α-Zn layer and the inhibition layer. After 4 % deformation the
average interface crack length increased linearly with the applied strain. This interface fracture was
strongly influenced by the crystalline orientation of the α-Zn grains.
Abstract: Authors have reported theses concerning the cast defect for publication in journal of Japanese Foundry
Engineering Society and AFS Transactions. This is a review of these reports. There are various factors in
the casting defect that occurs in the article of casting metal, and specific of the generation factor is difficult.
Moreover, it is necessary to decrease the casting defect to reduce the cost of goods manufactured and
energy of production. It is effective to the evaluation and the classification method of the casting defect to
employ Scanning Electron Microscopy with Energy Dispersion Spectrometer (SEM-EDS) and Electron
Probe Micro-Analysis (EPMA). Casting defects chose the one that the incidence was high and specific of
the generation factor is difficult, and the pinhole defect and inclusion defects were classified according to
the generation factor, and penetration defect showed the relation of physical factor, chemical factor, and
those interactions, and examined whether specific of the factor was possible by the surface analysis
equipment about other defects (Blow hole, Shrinkage, Orange peel, Cold shut, Cracks and Veining).
Abstract: Laser shock processing (LSP) has been presented as an effective technology for improving
surface mechanical and corrosion properties of metals, and is being developed as a practical
process amenable to production engineering. The main acknowledged advantages of the laser
shock processing technique consist on its capability of inducing a relatively deep compression
residual stresses field into metallic alloy pieces allowing an improved mechanical behaviour,
explicitly, the life improvement of the treated specimens against wear, crack growth and stress
corrosion cracking. In the present paper, practical results at laboratory scale on the application
of Laser Shock Processing are presented showing the obtained tensile residual stresses
relaxation along with corresponding preliminary results about the resulting mechanical
properties improvement induced by the treatment. Additionally, the influence of different
irradiation parameters will be presented along with a physical interpretation of the mechanical
effects induced in the materials by the characteristic fast laser-plasma interaction regime
occurring in the process and model based assessments on the real possibilities of the
technique as a substitutive of traditional techniques as, for example, shot peening. From a
specific point of view, a critical analysis of the relative influences of coupled thermal and
mechanical stress and deformation effects during LSP is presented.
Abstract: Al2O3 nano-particles were coated on the surface of LiNi1/3Co1/3Mn1/3O2
powder using a sol-gel method. The as-prepared Al2O3 nano-particle was identified to
the cubic structure of Al2O3. The average size of the isolated Al2O3 nano-particles after
heat treatments was calculated to be ~ 4 nm. The XRD showed that the structure of
LiNi1/3Co1/3Mn1/3O2 was not affected by the Al2O3 coating. At 3 wt.% Al2O3 coatings
on LiNi1/3Co1/3Mn1/3O2, the cyclic-life performance and rate capability were improved.
However, heavier coatings (5 wt.%) on LiNi1/3Co1/3Mn1/3O2 dramatically decreased the
discharge capacity and rate capability.
Abstract: Plasma spray deposition of hydroxyapatite (HA) coatings is a well established commercial
process. When deposited on metallic substrates, these coatings have been shown to promote bone
fixation and osteconductivity. A concern with current coatings is the formation of relatively large
debris particles during resorption. The size of the debris is related to the particle size of the powder
injected into the plasma during the deposition process. The use of solution precursors or dispersions
of fine particle size powders as the feedstock for plasma spraying has been shown to produce
submicron/nanocrystalline structured coatings from relatively inexpensive precursors.
Nanocrystalline HA coatings may improve the resorption of the coating in the body, avoiding the
irritant effect of large particles which may be seen in current thermal sprayed HA coatings.
We have explored the use of sols prepared from several different precursors as the feedstock for the
plasma spray deposition of HA coatings on Ti6Al4V substrates, employing statistical design of
experiments to establish optimal deposition conditions. We report on the formation and the
characteristics of the coatings as a function of the deposition parameters. The presence of different
Ca-P crystalline and amorphous phases was assessed by X-ray diffraction analysis. The coating
microstructure was characterized by scanning/transmission electron microscopy. The suitability of
the technique to coat biomedical implants is discussed.