Various Kinds Of Metals Research Articles

Maskless patterning of various kinds of metals onto porous silicon

AbstractPosition‐selective electrodeposition of various kinds of metals onto porous silicon (PS) with laser illumination is investigated. Maskless patterning of not only Ni, Fe, and Zn, less noble metals, but also Cu, a noble metal, was achieved by suppressing the immersion plating with chloride ions. The photo‐electrochemical behavior for each solution is compared. Similar results were obtained, especially in the cases of the less noble metals, indicating that the band structures of PS are in the similar condition. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Obliquely deposited metal films for polarizers

The performance of obliquely deposited metal films as polarizers, which can be used for normally incident light, was improved. The relation between microscopic columnar structures and dichroism of the films was investigated by depositing various kinds of metals with changing deposition angles. The influence of substrate materials was also examined. It was revealed that enlargement of the spacing between the neighboring columns is the most significant to attain a good extinction ratio and a low insertion loss. For the best performance, transmittances for p-polarization and s-polarization of 50% and 1%, respectively, at a wavelength of 681 nm were attained by depositing Al on poly(methyl-methacrylate) substrates at a deposition angle of 87°.

금속 코팅된 흑연 입자로 제조된 전극의 전기화학적 특성

Various kinds of metals were coated on synthetic graphite in order to investigate the relationship between film characteristics and their electrochemical performance. Gas suspension spray coating method was employed for the coating of synthetic graphite. In our experimental range, all of the metal coated synthetic graphite showed the higher capacity than that of raw material at high C-rate mainly due to decrease in impedance of passivation film. In cyclic voltammetry experiments, silver-coated and tin-coated graphite anodes found the lithium-alloy reaction. Considering smaller amount of metal coating, the most increase in discharge capacity was caused by improvement of conductivity of the electrode. When single-component metal was coated, silver-coated graphite anode exhibited the highest discharge capacity and better cycleability. Double components of silver-nickel coated active material showed the highest discharge capacity, rate capability and the best cycle performance in the range of our experiments.

Fabrication of a two-dimensional array of nano-particles using ferritin molecule

A new process is proposed which exploits protein-supramolecules as scaffolds for producing inorganic, functional nano-structures on a flat surface, and its feasibility is studied. A two-dimensional array of iron-oxide loaded ferritin molecules formed by self-assembly at an air/water interface is transferred onto a hydrophobic Si surface and the protein shell of the ferritin molecule is eliminated by 1 h heat-treatment at 500°C under nitrogen. Scanning electron microscopy (SEM) shows a well-ordered array of nanometer size dots on the Si surface. Atomic force microscopy (AFM) in contact mode indicates that the protein shell is eliminated by the heat-treatment, leaving only the iron cores. Fourier transform IR spectrophotometer (FTIR) analysis and weight measurements also indicate that the protein is selectively removed. From this result, together with the fact that ferritin molecules have the ability to accommodate various kinds of metals and metal complexes, it is feasible that nano-dot arrays suitable for quantum electronic devices can be fabricated by this method, which, in this paper, is called a ‘Bio Nano Process’. This newly proposed method will provide more economic mass-production than any other method.

Catalytic properties of metal loaded silica-pillared manganese titanate for CO oxidation

Semiconducting microporous solids were prepared by pillaring layer structured manganese titanate, Rb x Mn x Ti 2− x O 4 ( x=0.75) with silica. These solids were then chemically modified by loading various kinds of metals by cation exchange and impregnation methods. The samples with copper loaded by the impregnation method showed a high catalytic activity for the oxidation of carbon monoxide with oxygen. The highest activity was obtained for the sample with the copper content, [Cu]/[Cu+Mn]≈0.3; the CO conversion of more than 90% was achieved at 60°C. The high catalytic activity is attributed to the microporous pillared structure with a high porosity and the charge transfer between copper and the manganese titanate layers.

Microstructural feature of laser surface melting 1Cr17Ni2 stainless steel

During the past decades, considerable attention was focused on the laser surface processing on metals and alloys. This new surface processing method is one of the techniques available that may improve the surface properties of the alloys while keeping their bulk properties intact. By using a high-power laser beam, a thin surface layer of metals or alloys can be melted. After laser rapid melting and solidification, the microstructure and the properties of the laser melted layer may be improved substantially. Many investigators have studied the microstructure and the properties of laser melted layer of various kinds of metals and alloys. However, the mechanism of the formation of the microstructure in the laser melted layer needs to be understood further. In particular, more attention should be paid to the effects of alloying elements on the formation of the microstructure of laser melted layer during the solidification process. It is well known that 1Cr7Ni2 stainless steel possesses a high content of alloying elements. It exhibits the single {alpha}-phase after a conventional heat treatment. In the present work, the authors attempt to characterize the microstructural feature of the laser melted surfaces of 1Cr7Ni2 stainless steel and study the effects of alloying elements onmore » the formation of the microstructure of the laser melted layer during the solidification process.« less

リサイクリング シュレッダーダストの処理の現状と課題 西日本リサイクルマインパーク構想

It has recently become necessary to develop a system for dealing with the large amounts of shredder dust generated declining abandoned automobiles and home electric appliances because of landfill space nationwide and stringent regulations on leachate control. In 1992, about 1.2 million tonnes of shredders containing an estimated 36 thousand tonnes of copper, 3.6 thousand tonnes of lead, 6 thousand tonnes of zinc and 5, 400 Gcal were derived from automobiles. The shredders from home electric appliance disposal accounted for 230 thousand tonnes containing 22 thousand tonnes of copper. The amounts of shredder dust has been estimated to increase to 1.37 million tonnes by 2000, and to 1.56 million tonnes by 2005.A new project, the Recycle Mine Park (RMP) has been proposed to solve the problems of increasing amounts of automobile and home electric appliance scrap. The RMP uses technology to recover energy and metals. Since methods have been developed to recover energy and various kinds of metals including in base and hazardous metals, the largest problem of the project remains establishment of reasonable and economical system. About 30% of the shredder dust described above is generated in the western part of Japan.Smelters are located on the coast of the Inland Sea of Seto in this area, which reduces the cost of transportion. The recycing network in the western part of Japan excluding pretreatment combines the best features of being in the vicinity of a large amount of shredder dust, marine transportion and the presence of modern smelters. Pretreatment such as incineration or cracking which is additional treatment for the smelter feed is proved in small scale.Wehope that the unique system for recycing of shredder dust including collection, pretreatment, marine transportation and smeltering can be put into operation as soon as possible. The increasing costof suitable land for landfills, the stringent regulations on leachate control, and other costs makethis an attractive system.

Oriented overgrowth of metals onto poly-1,4-phenylene

Thin, oriented films of poly-1,4-phenylene (PPP) were prepared with a specially designed reaction vessel. Various kinds of metals were deposited by vacuum evaporation on the PPP substrate, the temperature of which was able to be changed up to 400 °C. Of the studied metals, tellurium and bismuth exhibited the oriented crystallization on it. The oriented overgrowth of tellurium crystallites occurred in the temperature range of 150 °C–200 °C. There were two modes of oriented overgrowths of crystallites in the case of bismuth; one was performed by deposition around room temperature and the other at about 100 °C. The oriented overgrowths of bismuth and tellurium on PPP were examined in terms of the mismatch parameter of the crystal lattice, and it was found that the overgrowths were caused by the lattice matching at the interface between the crystallites of the metals and the PPP substrate.

Retention of nitrogen implanted into metals

Retention of nitrogen implanted into various kinds of metals (Al, V, Ti, Fe, Co, Ni, Zr, Nb, Mo, Ta, and W) was calculated by the dynamic-SASAMAL code assuming planer surface binding energy and diffusion toward the surface for nitrogen over the concentration of saturated nitride phase. As the value of surface binding energy ( E s), the sum of the heat of sublimation of the metal ( H s) and the heat of formation of the nitride ( H f) times the nitrogen concentration ( C) at the surface layer was used ( E s = H s + CH f). The effects of values of H s, H f, and the displacement threshold energy on the retention were studied. The agreements between the calculated results and the experimental results obtained by NRA using 15N(p, αγ) 12C reaction were satisfactory for depth profiles and retention of nitrogen implanted into metals of Al, Ti, Ni, and Zr at a wide range of fluence from 6 × 10 16 to 6 × 10 17 ions cm −2.

On an unified model for predicting notch strength and fracture toughness of metals

In the present paper an unified model for predicting the notch strength and the fracture toughness, K IC , is given and checked on the basis of summarizing the recent research. The crack initiation at notch tip may be assumed to occur due to the fracture of the hypothetical material element located at notch root. Hence the crack initiation criterions are developed from the notch strain analysis and the well-known fracture criterions for various kinds of metals. If the fracture of the notched element occurs right after the crack initiation at notch tip without any subcritical crack propagation, the notch strength, i.e. the fracture stress of the notched element will be equal to the stress for crack initiation at notch tip. As a result, the formulae for predicting the notch strength from tensile properties are obtained for various kinds of metals. The formula for predicting the apparent fracture toughness, K 1A , can be also given in the same way. The predicted notch strength of metals agree well with the test results in literature. However, it should be pointed out that the predicted notch strength in plane stress state is the lower limit of the test results. More important may be that a new material constant, the so-called nonsensitivity-to-notch factor, is introduced to evaluate the notch sensitivity, or the notch toughness of metals. It has been pointed out that the crack must be bluntened during loading in order to keep the mechanical equilibrium at crack tip and the radius of the bluntened crack tip must have a critical value. Taking the bluntened crack as a sharp notch and ρ c as the critical radius of the bluntened crack tip, the formula for predicitng the fracture toughness, K IC , from tensile properties is obtained for the ductile metals, based the assumption mentioned above. For the steels with lath Martensite microstructure, ρ c will be equal to the strain hardening exponent in mm, and for steels with mixed Martensite structure ρ c is equal to the uniform elongation in mm, or the Austenite grain size, or 9 times of the dimple size. The difference between the predicted values of K IC and the test results are mostly less than 10. The values of K IC of aluminium alloys can be also predicted by a modified formula and the tensile properties.

Inference of critical cod from Charpy V test result

Correlation between the Charpy absorbed energy and critical COD is investigated to obtain a useful method for estimating critical COD from Charpy V data. The round bar tension test, Charpy V-notch test and static 3-point bend test with fatigue notched specimen are carried out using mild steel, 785 MPa grade high strength steel and A5083 aluminum alloy. Correlation is found between W' c/σ Y and δ c as well as between EW' c/σ Y 2 and Eδ c/σ Y , where W' c is the Charpy absorbed energy obtained by considering temperature difference between the Charpy transition temperature and COD transition temperature. The symbols σ Y, δ c and E are yield strength, critical COD and Young's modulus, respectively. The correlations are established for various kinds of metals and over a wide temperature range including not only upper shelf range but also the transition range.

Magnetic Properties and Structure of CoCr Thin Films

CoCr films with thicknesses ranging from 0.014 μm to 0.5 μm were prepared by dc magnetron sputtering onto PET film, using a CoCr alloy (18 wt% Cr) target. Thicker films are characterized by three zones with different magnetic properties. In the first zone, for thicknesses up to 0.03 μm, films have very low coercive forces H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> and small saturation magnetizations M <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">s</sub> , as well as a poor perpendicular anisotropy. In the second zone, for thicknesses from about 0.03 μm to 0.1 μm, the H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> and M <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">s</sub> vary, both passing through maxima, but the anisotropy field is smaller than that prevailing in the third zone. In this third zone, H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> gradually decreases with increasing film thickness, while M <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">s</sub> approaches a constant value and H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</sub> reaches its highest constant value. TEM studies showed CoCr films to have a fine columnar structure, with column thicknesses greater than 0.03 μm, and no changes in structure or column diameter were observed for films in the second and third zones. To investigate the effects of the underlayer, various kinds of metal were deposited on the PET film prior to CoCr deposition. Double-layer CoCr films exhibit higher H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> values than single-layer films, and have poor crystalline orientations. SEM observations indicate that CoCr films with a metallic underlayer have smaller grain sizes than do single-layer films.

Biodegradation of implant materials.

Various kinds of metals, ceramics, and polymers have been implanted into the human body to replace its failed or diseased parts. It is required that these biomaterials do not deteriorate in the living body, and that their mechanical, physical, and chemical properties are retained for the duration of service. However, almost all materials currently used for implantation more or less degrade in the biological environment. This article reviews several topics on the degradation and deterioration of metallic, ceramic, and polymeric biomaterials placed inside the body. The author conclusively remarks that biological effects on the mechanical properties of biomaterials should be studied more seriously by materials scientists and mechanical engineers in order to guarantee the safety and reliability of implant devices and artificial organs.

ＣｏＣｒ薄膜の磁気特性と構造

CoCr thin films having a thickness from 0.014 μm to 0.5 μm were prepared by D.C. magnetron sputtering method using CoCr (18 wt% Cr) alloy target on PET film. Thicker films are characterized on three zones which have different magnetic properties. In the first zone, films up to 0.03 μm thickness have very low coercive force Hc and small saturation magnetization Ms, and a poor vertical anisotropy. In the second zone from about 0.03 μm to 0.1 μm, Hc and Ms vary passing along the maximum value, but in this zone anisotropy field Hk is smaller than that of the third zone. In the third zone Hc gradually decreases with increasing film thickness, while Ms approaches a constant value and Ms reaches the highest constant value. TEM studies show CoCr films to have a fine columnar structure in thickness greater than 0.03 μm, and no changes in structure or diameter of the column have been observed in the 2 nd and 3 rd zones.To investigate the effects of the underlayer, various kinds of metal were deposited on the PET film prior to CoCr deposition. Double layered CoCr films exhibit higher Hc than single layer and have poor crystalline orientation. SEM observation shows that CoCr films on the metallic underlayer have smaller grain size than do single layered films.

シャルピ吸収エネルギと限界ＣＯＤの関係

Correlation between Charpy absorbed energy and critical COD is investigated to get a useful method for estimating critical COD from Charpy V data. Round bar tension test, Charpy V impact test and static 3-point bending test with fatigue notched specimen are carried out using mild steel, 80 kgf/mm2 grade high strength steel and A5083 aluminum alloy.Correlations are found between W'c/σY and δc, as well as between EW'c/σ2Y and Eδc/σY, where W'c is Charpy absorbed energy obtained by considering temperature difference between Charpy transition temperature and COD transition temperature. The symbols σY, δc and E are yield strength, critical COD and Young's modulus respectively. The correlations are established for various kinds of metals and over a wide temperature range including not only upper shelf range but also transition range.

Surface enhanced raman scattering (SERS) of chemisorbed species on various kinds of metals and semiconductors

Surface enhanced raman scattering (SERS) of chemisorbed species on various kinds of metals and semiconductors

Surface enhanced Raman scattering (SERS) of chemisorbed species on various kinds of metals and semiconductors

SERS spectra of pyridine adsorbed on various kinds of vacuum evaporated (10 −5 Torr) metals (Ag, Au, Ni, Pd, Pt, Ti and Co) and on single crystals of semiconductors (NiO and TiO 2) were obtained at room temperature. The peak frequencies as shifted from those of free pyridine are assigned to the bands of N-bonded pyridine (chemisorbed pyridine). The λ 0 dependence varied remarkably from metal to metal. The peak frequency and the λ 0 dependence for the pyridine adsorbed on NiO or TiO 2 are in good agreement with those on Ni or Ti, respectively, showing the chemical bonding between the N atom and the Ni or Ti atom. The effects of background and of polarization on the SERS spectra were examined in detail, thus revealing the orientation of the adsorbed molecules. Carbon monoxide chemisorbed on Ag was measured by infrared specular reflection as well as by SERS. The results indicate that chemisorbed species on the same substrate do not always give SERS. The SERS spectra obtained are well interpreted as being due to the mechanism of resonance Raman scattering via charge transfer excitation of the adsorbent-adsorbate interaction.

The measurement and calculation of loop temperatures in an FIM

A tip for FIM was made of various kinds of metals in order to monitor the tip temperature. A conventional four‐terminal method was used to measure the average temperature of the loop at the instant the tip melted. A computer calculation has also been carried out to obtain the temperature distribution in the loop and tip. The tip‐base temperature was obtained by matching the calculated loop resistance to the measured resistance. Finally, the calculated tip‐base temperature agreed well with the melting points of the tip materials to an accuracy of better than 99%.

ChemInform Abstract: DEALKYLATION REACTION OF ACETALS, PHOSPHONATE, AND PHOSPHATE ESTERS WITH CHLOROTRIMETHYLSILANE/METAL HALIDE REAGENT IN ACETONITRILE AND ITS APPLICATION TO THE SYNTHESIS OF PHOSPHONIC ACIDS AND VINYL PHOSPHATES

AbstractDie Verwendung von Chlortrimethylsilan/NaI in Acetonitril stellt ein wirkungsvolles und mildes Reagenz zur Spaltung von C‐O‐Bindungen unter neutralen und nichtwässrigen Bedingungen dar.

Dealkylation Reaction of Acetals, Phosphonate, and Phosphate Esters with Chlorotrimethylsilane/Metal Halide Reagent in Acetonitrile, and Its Application to the Synthesis of Phosphonic Acids and Vinyl Phosphates

Abstract A mild and efficient method has been developed for carbon-oxygen bond cleavage using chlorotrimethylsilane/sodium iodide in acetonitrile. It was applied to synthetic transformation under nonaqueous and neutral conditions, such as acetal deprotection and the synthesis of phosphonic acids from the corresponding dialkyl phosphonates via methanolysis of their silyl esters. Effectiveness of various kinds of metal or ammonium iodides for this type of dealkylation was examined in the acetonitrile solution by 1H NMR. Satisfactory results were also obtained with lithium or potassium iodide in place of sodium iodide. However, copper(I) or quarternary ammonium iodide was ineffective. Chlorotrimethylsilane/lithium bromide in acetonitrile is effective for selective dealkylation of multifunctional phosphonic esters or dialkyl vinyl phosphates.