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In this study, Ni-Al₂O₃-based composite clads on SS-316 substrates using a microwave irradiation method have been developed. Microwave-processed clads were characterized using various nondestructive techniques to investigate microstructure, phase analysis, porosity assessment and measurement of microhardness. The findings of the microstructural analysis demonstrated the formation of solid, metallurgically bonded and defect-free clads with a thickness of approximately 970$\mu$m. X-ray diffraction (XRD) phase analysis study confirmed the existence of hard and intermetallic phases in the clad region. Composite clad region exhibited a low porosity value of $\sim$1.3%. The average microhardness of the clad region was 3.63 times that of the substrate region. Further, cavitation erosion (CE) behavior of the developed clads was investigated using vibration CE test rig under various stand-off distances and immersion depths. CE results showed that the composite clads exhibited 6.9 times better erosion resistance than SS-316 substrate. CE resistance increased with an increase in stand-off distance and the depth of immersion.

CdSe nanoparticles were prepared by simply mixing Na₂SSeO₃ solution with CdSO₄ solution under [Cd²⁺]/[Se^2-] (Cd/Se) ratio of 1.2 at room temperature. The nanoparticles had an average size of 2.3 nm and showed fairly strong photoluminescence (PL) with a peak at 539 nm. Deposition of cadmium (II) hydrous oxide on the CdSe nanoparticles increased photoluminescence quantum yield from 3.1 to 34.8%, in comparison to Rhodamine 6G aqueous solution. Both of the CdSe nanoparticles and the cadmium (II) hydrous oxide deposited on CdSe nanoparticles were characterized as of cubic structure from XRD data and the electron diffraction (ED) patterns. Also, the reason for the photoluminescence enhancement was simply elucidated.

The biocompatibility of titanium implants with different surface properties is investigated. We prepared three types of specimens, one ground by the newly developed ELID grinding system, another ground by conventional ELID grinding, and the other polished by SiO₂ powder. These surfaces were characterized and, the number of cell and cytotoxicity in in-vitro were measured. Energy Dispersive X-ray Spectroscopy (EDS), X-ray Photoelectron Spectroscopy (XPS) and Transmission Electron Microscope (TEM) revealed that the modified ELID system can create a significantly thick oxide layer and a diffused oxide layer, and also can control the thickness of a modified layer. The results of cell number and cytotoxicity showed that the sample ground by the modified system had the highest biocompatibility. This may have been caused by improvement of chemical properties due to a surface modified layer. The above results suggest that this newly developed ELID grinding system can create the desirable surface properties. Consequently, this system appears to offer significant future promise for use in biomaterials and other engineering components.

When cavitation bubble is collapsed, shock wave which can deform metallic materials is produced. Cavitation impacts can be used for surface modification to enhance fatigue life of metallic materials in the same way as shot peening. As a peening method using cavitation impact does not require shots in shot peening, it is called “cavitation shotless peening CSP”. Although CSP can introduce compressive residual stress, i.e., macro-strain into metallic materials, full width at half maximum of diffractive X-ray profile was decreased by CSP. In the present paper, tool alloy steel for forging die was chosen as tested material to investigate mechanism of improvement of fatigue life, as CSP improved the life time of the forging die. The introduction of macro-strain was revealed by measuring residual stress, which was evaluated by X-ray diffraction method. The fatigue life was investigated by using a plate bending fatigue test changing with processing time of CSP. The micro-strain was evaluated by a fundamental parameter approach, which is one of X-ray diffraction method. It was concluded that the fatigue life of the steel was improved about 90 times by CSP and CSP can introduce macro-strain, i.e., compressive residual stress and releasing micro-strain. The micro-strain becomes about 1/20 of heat treated specimen by CSP.

In this study, the cracking behavior in the bulk and the stress-strain responses of partially crystallized Zr-Ti-Cu-Ni-Be bulk metallic glass after surface modification were investigated. The compressive plasticity was found to be dependent on the surface conditions. The plasticity was enhanced significantly by a complete removal of visible surface flaws. The electro-plating of copper on the rough surface also increased the plasticity of Zr base BMG of the present study. The beneficial effect of the electro-plating can be attributed to filling and smoothening effect due to plating and/or the ductilization of the surface, both of which does not favor crack nucleation. We also found the cracking behavior in the bulk different from the surface region. The cracks in the center of the sample were not straight, but wavy, suggesting the cracks were deflected by or attracted to crystalline particles. A high magnification view of a crack revealed small triangular shaped crystals along the crack path.

High current pulsed electron beam (HCPEB) has been developing as a useful tool for surface modification of materials. This paper presents our research work on surface modification of metallic materials, such as mold steel, stainless steel and magnesium alloy, with a HCPEB equipment of working parameters as electron energy 27keV, pulse duration ~1µs and energy density ~5J/cm². Investigations performed have shown that the most pronounced changes of phase-structure state and properties occurring in the near-surface layer. The formation mechanism of surface craters and their evolution regularity are discussed based on the elucidation of non-equilibrium temperature filed and different kinds of stress formed during pulsed electron beam treatment. After the HCPEB treatments, samples show significant improvements in measurements of wear and corrosion resistance.

The status of Mg alloy application, and then some key issues limiting their applications and the corresponding accesses were briefly discussed. It was supposed that development of new alloys with high performance and low cost, investigating advanced forming technology, and development of credible and effective surface modification technologies and related equipment were the urgent tasks in present. Correspondingly, three aspects of researches were carried out. (1) A new alloy with high strength and elongation, but low RE and Zn contents, named ZW21, was invented. (2) Semisolid ingots of AZ91D, AM60 and ZW21 alloys available for thixoforming were prepared. Thixoforming increased the ultimate tensile strength of AZ91D alloy by 20% compared with permanent mould casting. (3) A new kind of micro arc oxidation equipment with a capacity of treating 6m² surface was developed and has been used to treating motorcycle hub of magnesium alloy.

To investigate the possibility of developing a new surface modification method by the combined process of ELID grinding and high-temperature oxidization, we treated ELID finished specimens and polished specimens by high-temperature oxidization in the atmosphere and performed detailed analysis to determine how the treatment would change the specimen surfaces. The ELID-series showed high quality surface roughness and excellent tribological characteristics as compared with the polished-series. The improved surface properties of the ELID-series seem to result from formation of fine, uniform structures of spinel-type multiple oxides FeCr₂O₄ and Cr₂O₃ on the surface by high-temperature oxidization.

In plant cell walls, stiff semicrystalline nano dimensional cellulose microfibrils are embedded in a pliable amorphous matrix where the size and shape of the cellulose fibrils are controlled by the dimensions of crystalline regions, providing them a unique structural and physical combination to be applied as load-bearing constituent in composites. The qualities such as specific orientation under magnetic field, extraction through simple process, abundantly available source from nature and desirable modifications have deliberately directed the intense research efforts in a number of disciplines ranging from commodity to higher applications, not only in the area of high performance polymer based composites but also to develop biosensors, magnetic strips and optical devices. The present work is focused on the use of cellulose nano-fillers for creating the self-healing function and their effect on material properties of resulting composites. The present work is in initial stage and reviews the use of cellulose nano-fillers for creating the self-healing function and their effect on material properties of resulting composites.

Iron (Fe)-based nanoparticles are extremely valuable in biomedical applications owing to their low toxicity and high magnetization values at room temperature. In this study, we synthesized nearly monodisperse iron oxide (Fe₃O₄) and Fe@Fe₃O₄ (core: Fe, shell: Fe₃O${}_4)$ nanoparticles in aqueous medium under argon flow and then, coated them with various biocompatible ligands and silica. In this study, eight types of surface-modified nanoparticles were investigated, namely, Fe₃O₄@PAA (PAA = polyacrylic acid; $M_w$ of PAA = 5100 amu and 15,000 amu), Fe₃O₄@PAA–FA (FA = folic acid; $M_w$ of PAA = 5100 amu and 15,000 amu), Fe₃O₄@PEI–fluorescein (PEI = polyethylenimine; $M_w$ of PEI = 1300 amu), Fe@Fe₃O₄@PEI ($M_w$ of PEI = 10,000 amu), Fe₃O₄@SiO₂ and Fe@Fe₃O₄@SiO₂ nanoparticles. We characterized the prepared surface-modified nanoparticles using high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) absorption spectroscopy, a superconducting quantum interference device (SQUID), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) spectroscopy and confocal microscopy. Finally, we measured the cytotoxicity of the samples. The results indicate that the surface-modified nanoparticles are biocompatible and are potential candidates for various biomedical applications.

Electrical discharge machining (EDM) process is widely used to process hard materials in the industry. The process of electrical discharge is changed and called PMEDM when alloy powder is added in the oil dielectric. In this study, the effect of tungsten carbide alloy powder added in the dielectric on the microhardness of surface (HV) status of the workpiece SKD61 after machining is investigated. Studies show that the microhardness of surface obtained by PMEDM is generally better than that by normal EDM. The experiment shows that at the selected process window, adding the powder has resulted in an improvement of the microhardness up to 129.17%.

When saturated vapor passes over a colder substrate, liquid drops nucleate and grow by coalescence with surrounding drops. Typically speaking, nucleation and growth rates of water droplets are faster on a hydrophilic surface than on a hydrophobic surface. However, heat transfer efficiency degrades once surface becomes filmwise condensation. In this paper, vapor condensing on a gradient surface to prevent filmwise condensation is studied. New gradient surfaces are fabricated. It is demonstrated that 10% increase of condensation heat flux can be achieved on a silicon wafer with C = 1 mm gradient surface. The main mechanism for heat transfer enhancement is found to be that drops condensing on C = 1 mm gradient surface begin to move at a much smaller size compared with those on silicon wafer without modification.

Copper-matrix composites reinforced with SiC particles are prepared by mechanical alloying. The microstructure characteristics, relative density, hardness, tensile strength, electrical conductivity, thermal conductivity and wear properties of the composites are investigated in this paper. The results indicate that the relative density, macro-hardness and mechanical properties of composites are improved by modifying the surface of SiC particles with Cu and Ni. The electrical conductivity and thermal conductivity of composites, however, are not obviously improved. For a given volume fraction of SiC, the Cu/SiC_(Ni) has higher mechanical properties than Cu/SiC_(Cu). The wear resistance of the composites are improved by the addition of SiC. The composites with optimized interface have lower wear rate.

In this paper, corrosion behavior of an AISI 304 stainless steel modified by niobium or niobium nitride (denoted as niobized 304 SS and Nb-N 304 SS, respectively) is investigated in simulated solid polymer fuel cell (SPFC) operating conditions. Potentiodynamic polarizations show that the corrosion potentials of surface modified 304 SS shift to positive direction while the corrosion current densities decrease greatly comparing with the bare 304 SS in simulated anodic SPFC environments. The order of corrosive resistance in corrosive potential, corrosive current density and pitting potential is: Nb-N 304 SS > niobized 304 SS > bare 304 SS. In the methanol-fueled SPFC operating conditions, the results show that the corrosion resistance of bare and niobized 304 SS increases with the methanol concentration increasing in the test solutions.

Micro/nano-structured coatings with antibacterial function were prepared by microarc oxidation (MAO) treatment on Ti6Al4V alloy in a silicate/phosphate electrolyte with a NaF additive. The microstructure, phase composition, and corrosion resistance of the coatings modified by adding NaF (0.15–0.5 M) were examined using scanning/transmission electron microscopy, energy dispersive spectroscopy, atomic force microscopy, X-ray diffraction, and potentiodynamic polarization. The results showed that the incorporation of F ion reduced the threshold voltage for electrons avalanche on the surface film of the Ti alloy, and increased the intensity and lifetime of discharge. MAO coatings with 100–500 nm nano-pores and 1–20 $\mu$m micro-pores were formed by the modification of the NaF additive. The F ions promoted microarc discharge as well as phase transformation from the metastable anatase to the stable rutile phase. The F ions also promoted the generation of penetration cracks and bubbles in the coating. The surface roughness, phase content, and thickness of the coating were enhanced by the NaF additive. However, the corrosion resistance of the coating first increased and then decreased with the increasing F ion concentration, reaching a maximum when the NaF content was 0.25 M.

A surface-modified carbon nanotubes (CNTs), which shows an excellent electron field emission property was obtained in the present work. Conventional screen-printing technology was applied to prepare the CNT films. After hydrogen plasma surface treating process, the morphology of nanotubes surface were totally changed. Those modified CNTs exhibited low turn-on electron field of 0.98 V/μm, current density of 1 mA/cm² at a field of 6.53 V/μm and a very high emission site density of about 10⁶/cm², which is three orders of magnitude higher than that of untreated CNT films. Diode-type prototype devices were obtained which proved the modified CNTs is suitable for field emission displays.

Several different species of ions, Au, Fe, Ag, Ti and Si, were implanted into austenite stainless steel sheets at an energy of 3 MeV respectively. The martensite transformation induced with the ion implantation was investigated with transmission electron microscopy equipped with an energy dispersive X-ray spectrometer. The residual stresses induced with ion implantation were evaluated by the curvature technique. The effects of irradiation doses and ion species on the residual stress near surface induced by ion implantation were investigated. It is found that compressive residual stresses were induced by all the ions, and Fe and Au ions, among these ions, produced a higher level of residual stress at the same implantation. It shows that ion implantation can be employed to control and modify the internal stress near surface by changing the irradiation dose and selecting ion specie of the ion implantation.

With the fast development of new materials investigation, attention is paid to. The performance of superfine powders, which must be modified on the surface to acquire some points. Coating technology of particles is one especial method of surface modification. In this paper, coating methods of particles are classified into solid state, liquid state, and gaseous state, main methods and mechanisms during current time are reviewed, respectively, and some research examples are listed. The choice of diversified coating technologies is decided synthetically based on powder materials, performance of the modified substance, and application of coated powders. In the future, the researches of the core-shell modification mechanism, coated particles with an ordered arrangement coating layer, a new surface active agent, the facilities of suiting surface modification, and the evaluation methodology of the surface coating effect are very exigent and necessary for the preparation and application of superfine powders.

In this paper, the applications and qualifications of biomedical materials are introduced. In regard to the hard tissue implants, the biocompatibility can be improved by preparing various bio-ceramic and bio-glass coatings. In view of this, the principles, characteristics, and applications of surface modification (plasma spraying, electrostatic spray deposition, micro-arc oxidation, pulsed laser deposition, sol–gel deposition, and magnetron sputtering) in biomedical materials are reviewed. In addition, the research direction of improving biocompatibility by surface modification is presented.

The plasma treatment on SiO₂ substrate surfaces increased the oxygen-containing functional groups or the polar component of the surface free energy and, the wetting characteristics of the underfills/SiO₂. The plasma treatment condition which gave the smallest contact angle between the underfills and SiO₂ was an operating time of 60 sec under O₂ gas atmosphere and a power of 200 W.