Recent Advance of Metallic Materials toward Next Generation Electronics

This study evaluated the performance of composite restorations placed with two matrix and wedge systems 4years after placement. In a split-mouth design, 23 patients were selected and received at least two class II restorations, one with metallic matrix and wooden wedge and the other with polyester matrix and reflective wedge. One dentist placed the 109 restorations, and all cavities were restored using Single Bond and P-60 (3M ESPE) according to the manufacturer's instructions. Polymerization was performed through occlusal (metallic matrices) or through the reflective wedge (polyester matrices). Restorations were evaluated and categorized as alpha (A), bravo (B), charlie (C), and delta (D; modified United States Public Health System criteria) at baseline and 4years after placement. Both clinical aspects and interproximal radiographs were considered in the evaluation. Data were analyzed with Mann-Whitney and Friedman tests (α = 0.05). Fifteen subjects (78 teeth/102 proximal surfaces) were reassessed after 4years. Considering comparisons within matrices in different evaluation time points, no significant differences were observed (p > 0.05). Comparing 4-year to baseline results, the quality of marginal adaptation (40% and 40.4 %, score A), marginal staining (31.3% and 28.8%, score A), and roughness (56% and 46.2%, score A) decreased for metallic and translucent matrices, respectively (p < 0.05), while color match (9.6%, score A), occlusal contacts (75%, score A), and proximal contacts (71.7%, score A) also decreased in quality for translucent matrices (p < 0.001). Although the matrix and wedge systems evaluated showed similar clinical performance, there was clinical quality loss after 4years, with most of the restorations being still acceptable, and no intervention was necessary.

Metal materials, supporting plasmon modes on their surface, can confine the optical field at deep subwavelength scale, which is desired for photonic integration. However, their intrinsic high Ohmic losses make it impossible to construct the whole circuit solely with the metal materials. Integrating the plasmonic components with dielectric materials may offer a solution to this dilemma. With outstanding active optical performance, these dielectric components not only can greatly reduce the optical losses of the entire circuits but also offer an efficient way to launch the surface plasmon polaritons through the evanescent field coupling or the direct exciton-plasmon conversion. Furthermore, the cooperative interaction between metal and dielectric materials would bring vast novel optical phenomena and functional photonic devices. In this review, the synergistic effects among metal and dielectric materials in various heterostructures as well as their related applications are highlighted. Comprehensive understanding on their synergistic interactions would offer useful guidance for the design and fabrication of the ultracompact novel optical devices.

Microstructured metallic gratings can be used to enhance the light emission efficiency of LEDs, and the spectral radiation properties of the LEDs vary with the different metallic materials used, leading to variation of the light emission enhancement at the same wavelength for different metallic grating materials. In this paper, the finite difference time domain (FDTD) method has been used to investigate the light emission extraction enhancement of LEDs in which gratings with different metallic materials have been applied. Through analysis of the permittivity of the metals and the quality factors of the surface plasmons (SPs), we concluded that the larger the plasma frequency obtained for the metallic interband transition, then the more suitable the metals are for light emission extraction of photons with relatively short wavelengths. This is because of the abundance of free electrons in the metals with large plasma frequencies. We also found that the wavelength-dependent trends of the extraction enhancement resulting from the scattering mechanism for different metallic materials are similar to each other. For SP-induced enhancement, either the enhancement peak position or the peak value changes significantly with the different metals.

Now, the people who substitute a joint, the tooth that a function deteriorated for an artificial joint, an artificial root increase rapidly. Therefore the characteristic found to artificial materials becomes higher very much. The metal materials are used as implant materials widely, and it is often that the fewness to show the toxicity is controlled by metal corrosion resistance. I was aimed for the chemical evaluation of metallic bio materials and I examined metallic bio materials based on the testing method for corrosion resistance of metallic bio materials by anodic polarization measurement (JIS T 0302) standardized by JIS. As a result, the oxidation film of stainless steel and Co-Cr-Mo alloy is appeared the peak of the current density in Eagle MEM. But the oxidation film of Zr-2.5Nb alloy is not

Some metallic materials exhibit good damping capacity of mechanical energy into thermal energy. This property along with the others metallic characteristics make this materials interesting for a big number of applications. These materials can be used as bumpers in different applications including automotive field. Beside grey cast iron and shape memory alloys few new metallic materials are presented for the supposition of high damping capacity. We analyze the causes that increase the internal friction of some metallic materials and possibilities to enhance this property through different mechanical, physical or chemical methods. Shape memory alloys, especially those based on copper, present a different damping capacity on martensite, austenite or transition state. In the transformation range M ↔A, which in case of copper base shape memory alloys is quite large, the metallic intelligent materials present a high internal friction, almost comparable with natural rubber behavior that can transform mechanical energy into thermal energy till a certain value of the external solicitation. These materials can be used as noise or small vibrations bumpers or even as shock absorbers in automotive industry.

With the progressive expansion of hydrogen fuel demand, hydrogen pipelines, hydrogen storage cylinders and hydrogen refuelling stations (HRSs) are the primary components of hydrogen energy systems that face high-pressure hydrogen environments. Hydrogen embrittlement (HE) is a typical phenomenon in metallic materials, particularly in the high-pressure hydrogen environment, that causes loss of ductility and potentially catastrophic failure. HE is associated with materials, the service environment and stress. The primary mechanisms for explaining the HE of materials are hydrogen-enhanced decohesion, hydrogen-induced phase transformation, hydrogen-enhanced local plasticity, adsorption-induced dislocation emission and hydrogen-enhanced strain-induced vacancy. To reduce the risk of HE for metallic structural materials used in hydrogen energy systems, it is crucial to reasonably select hydrogen-resistant materials for high-pressure hydrogen environments. This paper summarizes HE phenomena, mechanisms and current problems for the metallic structural materials of hydrogen energy systems. A research perspective is also proposed, mainly focusing on metal structural materials for hydrogen pipelines, hydrogen storage cylinders and hydrogen compressors in HRSs from an application perspective.

Explosive shock and Q-switched laser exposure of metallic and ceramic materials have produced varied substructures and increased hardness that possibly emphasize the role of the attendant material structures and the nature of the defect substructures that are subsequently obtained. In metallic materials, Q-switched laser exposure is seen to result in extensive heating as well as shock wave passage effect, while the control of temperature in explosive detonation is seen to introduce shock effect and associated defect substructure. For example, explosive shock exposure of Al-Li 8090 alloy is seen to increase hardness, reduce activation energy for subsequent ageing, introduce precipitation, revealing the extensive role defect substructure plays in the ageing kinetics of this alloy. Shock loading of Molydenum at 150 kbar (for 2 μs) increases dislocation loop densities from 5x10/cm to 4x10/cm with 75% of the loop types analyzed being vacancy loops. Irradiations utilizing a Q-switched laser at also of Mo at fluences between 22 and 35 J/cm produced residual effects ranging from increasing numbers of lattice vacancies and vacancy clusters to massive deformation, cavitation, and spallation along with melting. Finally, explosive shock exposure, at various calculated pressures, of Al203, Al203+Zr02, Al203+SiC (whisker), Al203+Zr02+SiC (whisker), showed no significant difference in mechanical properties of hot-pressed Al203+Zr02 composites with regard to shock treatment. Improved mechanical properties were occasionally found in shock-treated and hot-pressed whisker-reinforced alumina, although a direct relationship with shock pressure was not observed. The manuscript summarizes these different studies in delineating the role of shock waves passage in the subsequent material processing. This is an overview of these research projects and fuller details can be found in the cited references. www.witpress.com, ISSN 1743-3509 (on-line) © 2006 WIT Press WIT Transactions on The Built Environment, Vol 87, Structures Under Shock and Impact IX 147 doi:10.2495/SU060151 1 Laser and shock exposure of metallic materials Essentially, all laser interactions with metals involve the absorption of all or a portion of the light energy and its conversion to heat with or without a change in phase of the surface material. For radiation from Q-switched lasers, the interaction with metals has been considerable in terms of the surface rising to the vaporization temperature and vaporization being initiated. As materials recoil against the surface, high-pressure stress waves (or shock waves) can be generated. This pressure pulse raises the boiling point of the underlying material which becomes superheated as more heat is conducted into the interior. In effect, the thermal expansion which follows the rapid absorption of radiant energy at the surface of an elastic solid can propagate a shock wave into the interior. An important feature which distinguishes Q-switched laser interaction from that of a CW laser is the extremely large temperature gradients and the time rates of change of temperature (>10°C/s) involved. Since the production of stress waves in solids using high-powered pulsed lasers is fundamentally a surface phenomenon, the magnitude of those stress waves can be modified by modifications in the target surface conditions. Laser-shock effects should be expected to be fundamentally different from those produced by plane shock waves generated by explosively driven flyer plates and the like because the laser generated shock waves will propagate from a small source region, the impinging laser beam spot, creating a radially attenuating stress pulse, while in conventional shock-loading case, the material is considered to be characterized by a uni-axial strain state which in most instances is not large and allows for a hydrostatic stress approximation [1].

Metallic amorphous materials are of high strength, high corrosion resistance, high permeability and other industrially important and useful properties. Furthermore, new metallic materials can be produced from metallic amorphous materials by proper crystallization processes, usually heat treatment, to meet the various industrial demands. In subvolume A, 8327 points of formation data of 1532 ternary amorphous alloys consisting of 351 ternary systems have been extracted, classified and evaluated. Preparation methods, atmosphere for preparation of amorphous alloys, sample form and size and phase identification methods are provided. Composition data are given in phase diagrams and tables. Subvolume B is in preparation.

A novel model for obtaining both equi-biaxial and uniaxial residual stress of metallic materials by instrumented sharp indentation

Elastic modulus plays a key role in the application of porous metallic materials. However, to the best of our knowledge, few attempts have been made to model the simultaneous dependence of elastic modulus on temperature and porosity for metallic materials. The present article contributes to a rational temperature-porosity-dependent elastic modulus model for metallic materials with all parameters having definite physical significance. The model can well predict the elastic moduli of porous metallic materials, from extremely low temperature to ultrahigh temperature, and from dense material to about 0.9 porosity, with reference to an easy-to-access elastic modulus. In a special case, when intrinsic elastic modulus [M] = 2 and critical porosity P C = 1, a phenomenological parameter-free predictive model can be obtained. The model can be applied when the matrix Poisson ratio is 0.1 &lt; v &lt; 0.4 for Young’s modulus and 0.17 &lt; v &lt; 0.27 for shear modulus, which covers most metallic porous materials.

The influence of well fluids and external environments, including offshore and cold weather, on metallic and non-metallic materials is discussed. Methods of selection based on field data, assisted by accelerated laboratory testing, is dealt with in detail Tabulations or material in everyday use are shown, including carbon steels, low alloy steels, stainless steel and elastomers, with suggestions for specific uses. The selection of materials for petroleum production operations is based primarily on environmental compatibility. cost is an important but secondary consideration. Through the years, users and manufacturers have come to realize that a rather large group of economical materials will serve adequately in a large percentage of fields. Cold weather operations, hydrogen sulfide, carbon dioxide, all influence the need for special materials or routine materials in a different condition. Chosen materials must be compatible with oil and gas environments as encountered in the production cycle. Well streams contain oils, condensates, methane, carbon dioxide, nitrogen, hydrogen sulfide, ethane, and many heavier fractions plus salt water in varying concentrations and quantities. plus salt water in varying concentrations and quantities. Methane is the least harmful as to its effect on metallic materials. Table No. I illustrates the effect of individual fractions on metallic materials. Two basic failure modes are encountered in petroleum production:stress corrosion cracking due to hydrogen production:stress corrosion cracking due to hydrogen sulfide and/or chlorides, andmetal loss in the form of pitting or general corrosion. pitting or general corrosion. Both failure modes are very important but pitting may be more misleading in that if a corrosion monitoring system is based on well stream iron count, the observer may be content, this while his tubing is being perforated in a zone not of his choosing! Sufficient data has been accumulated through field experience to permit users and manufacturers to evaluate the problem and make reasonably accurate predictions as to the performance of a material in specific environments. When new performance of a material in specific environments. When new alloys or new applications for established alloys are considered, accelerated laboratory testing can be helpful for screening purposes prior to field testing. purposes prior to field testing. Internal and external accessory items are made from the various materials shown in the tables on the next page. Table No. 2 and 3 offer several materials in common use for parts wetted by the well stream. parts wetted by the well stream.

Anterior spine decompression and reconstruction with bone grafts and fusion is a routine spinal surgery. The intervertebral fusion cage can maintain intervertebral height and provide a bone graft window. Titanium fusion cages are the most widely used metal material in spinal clinical applications. However, there is a certain incidence of complications in clinical follow-ups, such as pseudoarticulation formation and implant displacement due to nonfusion of bone grafts in the cage. With the deepening research on metal materials, the properties of these materials have been developed from being biologically inert to having biological activity and biological functionalization, promoting adhesion, cell differentiation, and bone fusion. In addition, 3D printing, thin-film, active biological material, and 4D bioprinting technology are also being used in the biofunctionalization and intelligent advanced manufacturing processes of implant devices in the spine. This review focuses on the biofunctionalization of implant materials in 3D printed intervertebral fusion cages. The surface modifications of implant materials in metal endoscopy, material biocompatibility, and bioactive functionalizationare summarized. Furthermore, the prospects and challenges of the biofunctionalization of implant materials in spinal surgery are discussed.Fig.a.b.c.d.e.f.g As a pre-selected image for the cover, I really look forward to being selected. Special thanks to you for your comments.

This report describes the result of the first eight months of effort on a project directed at improving metallic interconnect materials for solid oxide fuel cells (SOFCs). The results include cyclic oxidation studies of a group of ferritic alloys, which are candidate interconnect materials. The exposures have been carried out in simulated fuel cell atmospheres. The oxidation morphologies have been characterized and the ASR has been measured for the oxide scales. The effect of fuel cell electric current density on chromia growth rates has been considered The thermomechanical behavior of the scales has been investigated by stress measurements using x-ray diffraction and interfacial fracture toughness measurements using indentation. The ultimate goal of this thrust is to use knowledge of changes in oxide thickness, stress and adhesion to develop accelerated testing methods for evaluating SOFC interconnect alloys. Finally a theoretical assessment of the potential for use of ''new'' metallic materials as interconnect materials has been conducted and is presented in this report. Alloys being considered include materials based on pure nickel, materials based on the ''Invar'' concept, and coated materials to optimize properties in both the anode and cathode gases.

Development and application of carbon fiber in batteries

Novel Growing Integration Layer (GIL) method for joining/bonding of metallic and ceramic materials, and its applications for bulk metallic glasses with high bioactivities