A single water monomer is known as a hard-to-observe molecule even in the presence of metal surfaces as supporting matrix. This review highlights effort in experimental characterizations and theoretical modeling of transition metals supported water monomers with attention given to its structure and bonding, together with the insights that we have provided into the bonding nature of the water-interactions by the newly employed projected PDOS (partial density of states) difference analysis, which is proved to be an effective tool to be elucidate such bonding nature. The general s-d hybridization and d-shell effect are summarized, and how these effects can be tuned by tailoring local surface configurations is discussed.

Oxidation protective MoSi₂-Mo₅Si₃/SiC multi-coatings for carbon/carbon composites were prepared by chemical vapor reaction and slurry-sintering method. The influence of preparation technology on the structure and phase composition of the coating was investigated by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analyses, and then their relationship was discussed. The results indicate that the Si/Mo ratio of the slurry and sintering processing were two main factors that significantly affected the structure and phase composition of the multi-coating. Appropriate sintering process and relatively high Si/Mo ratio were essential for preparing the multi-coating with dense structure and favorable phase composition. After being sintered at 1723 K for 2 h and with the Si/Mo ratio of the slurry being 4.5 (weight ratio), a dense structure accompanied by favorable phase composition of the coating can be obtained. When heat treated at 2373 K for 1 h, this coating became more compact and continuous. Oxidation tests (performed at 1623 and 1823 K) demonstrated that both of these two obtained multi-coatings exhibited better anti-oxidation property than single layer SiC coating.

Thick and dense oxide layers were obtained on aluminium in sulphuric acid electrolyte. For this purpose, the methodology of experimental design was used. A three-variables Doehlert design (bath temperature, anodic current density, sulphuric acid concentration), was achieved. In order to maximize the growth rate and the density of the anodic oxide layer, optimum path study was conducted. Under the determined optimal anodizing conditions (5.7°C, 3 A·dm^-2, C_sul=140 g·L^-1), the estimated response values were 0.86 μm·min^-1 and 3.12 g·cm^-2 for growth rate and density, respectively. The morphology of optimum layer was examined by scanning electron microscopy (SEM). The compactness of the optimum anodic layer can be correlated with its morphology revealed by SEM observations.

Ti(C, N) multilayer films have been prepared by closed-field unbalanced magnetron sputtering technology and using graphite target as the C supplier. Microstructural observation results showed that the Ti(C, N) films exhibited multilayer structure with most of fine nano-columnar Ti(C, N) grains existing in the films. The current of graphite target had an effect remarkably on the multilayer structure of films: the periodical thickness gradually increased as the current went up, but the grain size of films gradually decreased and even amorphous phase appeared as the current further increased. The microstructure of Ti(C, N) films changed from columnar crystallite to nanocomposite in high current of graphite target where the fine Ti(C, N) grains were distributed uniformly in the amorphous Ti(C, N) matrix, and the volume fraction of the amorphous phase increased with increasing current. Measurement results showed that the Ti(C, N) multilayer films have high microhardness and low friction coefficient, and especially the film  deposited in the current of 0.9 A exhibits superior properties with optimizing hardness and friction coefficient. Based on the relationship of the microstructure and the properties of films, the multilayer structure and fine grain size of Ti(C, N) films are responsible for their well mechanical and friction properties. And choosing the graphite target as the C supplier is more propitious to decrease the friction coe±cients of films.

Comparative experiments were conducted to reveal the removal behaviors of three kinds of silicon carbide (SiC) ceramics during polishing and the effects of ceramic microstructure on the surface quality were also reported. Experimental results show that the second phase in SiC ceramics plays an important role in the surface quality when its size is large enough. The surface quality is enslaved to the formation of steps at interfaces between second phase and SiC matrix that results from different elastic  modulus and hardness between two phases. Under 3 μm abrasive grains polishing condition, different SiC ceramics show different removal mechanisms. With decreasing abrasive grain size, all of different SiC ceramics exhibit a ductile removal mode, which decreases surface roughness effiently.

The effects of oxygen on the microstructure of Ti-47Al-0.7B (at. pct) alloy for as-cast automotive valves were investigated. Six alloys with oxygen content from 0.4 to 1.4 at. pct were prepared by induction melting and centrifugal casting in CaO crucible under protective atmosphere. The microstructures were observed by optical microscopy (OM) and scanning electron microscope (SEM). The results show that the increase of oxygen content led to grain refinement and enhanced the microhardness as well as the α2 volume fraction in the TiAl-based alloys.

The directional solidification has been carried out for the Al-4Bi-2.5Co (wt pct) alloys with different melt superheat temperatures. The microstructure characterization and the quantitative metallographic analysis have been performed. The results indicated that the Bi-rich sphere size and cellular spacing decrease with increasing melt superheat temperature. The interaction between the advancing solidification interface and the Bi-rich spheres with different sizes was analyzed. The effect of the melt superheat treatment on microstructure evolution was discussed for the immiscible alloys. The microstructure development in ternary Al-Bi-Co alloys directionally solidified with different melt superheat temperatures was clarified.

The influences of pre-ageing temperature and natural ageing time on subsequent artificial age hardening behavior and precipitation sequence of new type Al-1.01Mg-0.68Si-1.78Cu alloy were investigated by hardness test, differential scanning calorimetry (DSC) test and transmission electronic microscopy (TEM) observations. When pre-ageing temperature is 20°C (natural ageing), the peak hardness of subsequent artificial aged alloy is lower than that of T6 treated alloy (negative effect), while a positive effect appears when pre-ageing temperature is above 80°C. The size of needlelike β-precipitate in subsequent artificial aged alloy is much coarser when pre-ageing temperature is 20°C, which causes a decrease in peak-hardness. The positive effect occurs again when natural ageing time is longer than 3 weeks. There are seven exothermic peaks in DSC curve of as-quenched alloy, while the number and height of exothermic peak decrease with increasing pre-ageing temperature and natural ageing time.

Similar element substitution has been applied for improving glass forming ability (GFA) in Al₈₆Ni₉La₅ amorphous alloy. The effects of La-Ce and Ni-Co pairs on the GFA, magnetic properties and hardness of Al-Ni-La alloy were investigated by using X-ray diffraction (XRD), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), magnetometer and hardness-tester. The results show the GFA of the samples in the order of Al86(Ni_0:5Co_0:5)9(La_0:5Ce_0:5)5< Al₈₆Ni₉La₅<Al₈₆Ni₉(La_0:5Ce_0:5)₅, implying that similar element substitution has a limited enhancing effect on the GFA of the present Al-Ni-La alloy. In addition, the measured samples display a diamagnetic behavior at room temperature. The variations of diamagnetic behavior as well as the microhardness of the samples are strongly dependent on the  icrostructure, i.e., the amounts of the icosahedral structure and precipitates, after the similar element substitution in the Al-Ni-La alloy.

This study investigated the microstructures and mechanical properties of ZK60 alloy prepared by a simplified rapid solidification powder metallurgy (RS P/M) processing system (S-RS P/M), which consists of warm press in dry air and hot extrusion. Microstructure characterizations showed that S-RS P/M alloy consisted of magnesium matrix and oxide stringers of ~1 μm in width. TEM (transmission electron microscopy) observations illustrated nano-size magnesia particles (10{30 nm) constituted oxide stringer in detail. Due to a relatively higher volume of nano-size magnesia particle produced during S-RS P/M process, 0.2% yield strength of S-RS P/M ZK60 alloy was found to be as high as 382 MPa, which is 10% higher than that of RS P/M alloy. The improvement in mechanical properties is mainly attributed to the combination effects of Orowan mechanism and coe±cient of thermal expansion (CTE) mismatch because of the approximately same average grain size.

Sn-10Sb-5Cu lead-free solder was fabricated for high temperature application in electronic package. Wetting behaviors and interfacial reaction between such a high temperature lead-free solder and Cu substrate were investigated and compared with those of 95Pb-Sn solder. The results showed that the wetting properties of Sn-10Sb-5Cu solder are superior to those of 95Pb-Sn solder in maximum wetting force, wetting time and wetting angle in the temperature range of 340{400°C. However, the surface of the Sn-10Sb-5Cu solder sample after wetting balance tests was rougher than that of 95Pb-Sn solder at the temperature lower than 360°C. In static liquid-state interfacial reaction, the types and thickness of the intermetallic compounds (IMCs) of both solders were different from each other. The wetting kinetics in the Sn-10Sb-5Cu/Cu system was more rapid than that in 95Pb-Sn /Cu system, and the higher formation rate of IMCs in the former system was considered as the reason.

In the present study, a grade of stainless steel (SS, 410) and copper plates were joined through diffusion bonding by using a nickel interlayer at temperature range of 800−950°C. These were performed through pressing the specimens under a pressure of 12 MPa for 60 min under 1.33×10^-2 Pa (10^-4 torr) vacuum. The microstructure and phase constitution near the diffusion bonding interface of Cu/Ni and Ni/SS were studied by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and an elemental analyses through energy dispersive spectrometry (EDS). The results indicated that an obvious diffusion zone was formed near both Cu/Ni and Ni/SS interfaces during the vacuum diffusion bonding. The thickness of reaction layer in both interfaces was increased with increasing process temperature. The diffusion transition region near the Cu/Ni and Ni/SS interfaces consist of complete solid solution zone and various phases based on (Fe, Ni), (Fe, Cr, Ni) and (Fe, Cr), respectively. From EDS results, three different mixtures of phases were distinguished in SS-Ni interface. The activation energy and rate constant were determined for the growth of these reaction layers and the values become maximum for the {γFe, Ni+αFe+Cr} phase mixture.

Double shielded gas tungsten arc welding (GTAW, also known as tungsten inert gas (TIG) welding) of an SUS304 stainless steel with pure inert argon as the inner layer shielding and the Ar-CO₂ or CO₂ active gas as the out layer shielding was proposed in this study to investigate its effect on the tungsten electrode protection and the weld shape variation. The experimental results showed that the inner inert argon gas can successfully prevent the outer layer active gas from contacting and oxidizing the tungsten electrode during the welding process. Active gas, carbon dioxide, in the outer layer shielding is decomposed in the arc and dissolves in the liquid pool, which effectively adjusts the active element, oxygen, content in the weld metal. When the weld metal oxygen content is over 70×10^-6, the surface-tension induced Marangoni convection changes from outward into inward, and the weld shape varies from a wide shallow one to a narrow deep one. The effect of the inner layer gas flow rate on the weld bead morphology and the weld shape was investigated systematically. The results show that when the flow rate of the inner argon shielding gas is too low, the weld bead is easily oxidized and the weld shape is wide and shallow. A heavy continuous oxide layer on the liquid pool is a barrier to the liquid pool movement.

Zr₅₅Al₁₀Cu₃₀Ni₅ bulk metallic glass was rolled up to 95% in thickness reduction at room temperature, and the dependences of microstructure and thermal stability on the strain were investigated. It is revealed that phase transformations do not occur during the rolling, but the split of the crystallization peaks becomes more and more obvious with increasing thickness reduction. Analyses of the radial distribution functions and the pair correlation functions indicate that the rolling has enhanced the short-range order, which should be responsible for the enlarging split of the crystallization peaks.

The aim of the present work was to study the effect of austenite grain size (AGS) on the martensite formation in a high-manganese twinning-induced plasticity (TWIP) steel. The results of a quantitative microstructural characterization of the steel by the whole X-ray pattern fitting Rietveld software, materials analysis using diffraction (MAUD), indicated that the volume fraction of ffbcc-martensite increases with increasing AGS. However, the value of the stacking fault probability (Psf ) does not show a large variation for samples with different values of AGS under water-quenching conditions.

Stainless steel plates were successfully coated with SnO₂-CeO₂ films (SS/SnO₂-CeO₂) by brush coating with a solution of stannous chloride and cerium trichloride followed by thermal decomposition. It is proven that the properties of SnO₂ films can be evidently improved by Ce doping, and 600°C is the optimum temperature to prepare SS/SnO₂-CeO₂ anodes. The physicochemical and electrochemical properties as well as the electrocatalytic activity of the electrodes were investigated. It is found that the novel electrodes have compact microstructure, high overpotential for oxygen evolution (1.60 V vs SCE), excellent electrochemical stability, relatively low cost and excellent catalytic activity for oxidizing pollutants. An industrial dye wastewater, which is hard to be purified by using conventional chemical flocculation methods, was oxidated by employing the SS/SnO₂-CeO₂ anodes, and 83.00% of color and 48.62% of chemical oxygen demand (COD) removal was achieved under the cell voltage of 5 V within only 2 min, and the electricity consumption is only 1.83 kWh for oxidizing 1 m³ of dye wastewater.