bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrical Properties of La0.7Sr0.3CuO3-δCathode Based on SDC-YSZ Composite Electrolyte
Authors: Zheng Min Zhang , Liu Xiao Mei
Published: May 2013

The cathode material La0.7Sr0.3CuO3-δ was synthesized by a sol-gel method. X-ray diffraction revealed it to be form a single phase of perovskite. The SDC（Sm0.15Ce0.85O1.925）was synthesized by glycine-nitrate processes. The 90%SDC and 10%YSZ powders are mixed to prepare as SDC-YSZ composite electrolyte. The high temperature electrical conductivity of La0.7Sr0.3CuO3-δ was measured by using the four-point dc technique, and cathodic overpotential with SDC-YSZ composite electrolyte support was measured by using a current-interruption technique. Using La0.7Sr0.3CuO3-δ as cathode and 65%NiO/SDC as anode based on SDC-YSZ composite electrolyte one can obtain high current density and power density at intermediate temperatures.
Electronic and Magnetic Properties of Li1.5Mn0.5As Alloys in the Cu2Sb Structure
Authors: Fong C.Y. , Damewood Liam , Yang L.H. , Felser C.
Published: May 2013

We investigated two formula-units of Li1.5Mn0.5As alloys, such as Li3MnAs2, in the Cu2Sb crystal structure using an ab-initio algorithm. By interchanging Mn with each Li located at different positions of the Li4As2unit cell, four separate alloys are formed. At the optimized lattice constant, two of these alloys are predicted to be ferromagnetic metals and the other two are half metals. The possibility of half metallicity in the first two is also explored. Both the modified Slater-Pauling-Kübler rule and the ionic model can characterize the magnetic moments of the half metals.
The Electrical Characterization of p-CdTe/n-Si (111) Heterojunction Diode
Authors: Razooqi Mohammed A. , Abdulameer Ameer F. , Hameed Adwan N. , Abdullaha Rasha A. , Sabbar Ehsan I.
Published: May 2013

p-CdTe film has been deposited on n-Si(111) substrate by thermal evaporation technique. The prepared CdTe/Si heterojunction diodes have been annealed at 573K. The capacitance-voltage measurements have studied for the prepared heterojunctions under 2 KHz frequencies. The capacitance-voltage measurement indicated that these diodes are abrupt. The capacitance at zero bias, the built in voltage and the doping concentration increased after annealing process while the zero bias depletion region width is decreased. The carrier transport mechanism for CdTe/Si diodes in dark is tunneling-recombination. From current-voltage measurement at dark, the values of ideality factor are 2.9 and 3.8. The values of reverse saturation current are 3.77×10-7and 9.36×10-8Amperes.
Simulation of Movement of Drill Rods at Large Deformations
Authors: Khajiyeva Lelya , Kydyrbekuly Almatbek , Sergaliyev Almaz , Umbetkulova Aliya
Published: May 2013

The purpose of the paper is modeling of nonlinear vibrations and stability of movement of boring columns at finite deformations. Movement of boring columns for shallow drilling (up to 500 m) applied in oil-gas extractive industry is considered. Nonlinear models of movement of acompressed-torsioned drill rod within the nonlinear theory of finite deformations of V.V. Novozhilov are constructed. A method for its analysis and criterion of dynamic stability are offered. The numerical analysis of its elastic dislocations and instability zones of the basic resonance is carried out, which confirm the efficiency of the offered nonlinear dynamic model of rod elements and techniques for their calculation.
The Concrete Casting Matrixes Inserts Design Preparation Based on the Master Models
Authors: Grabowik Cezary , Janik Witold
Published: May 2013

Currently industrial needs exceed traditional design approach solutions. To satisfy that need designer have to deal with mutually exclusive restrictions. The solution to this problemis to maintain these restrictions with proper methodthat guarantees right result. The concrete casting matrixes are not only transits beauty and art but they have also important technical sense in final product. The master model represents the final product a concrete sidewalk brick which have specified form of the top surface. This special structure of the top surface helps drain water off the brick in order to maintain proper griping properties of it after it rains. As soon as the master model wasscannedit was necessary to change outer border line of 3D model because themaster model appeared to be a little bit bigger than the original one. Finally the 3D model it is the outer border line and its geometry were modified in order to keep the original model functionality. All modifications were done with application of reverse engineering and CAD/CAM software.
Effect of Casting Design to Microstructure and Mechanical Properties of 4 Mm Twdi Plate
Authors: Sulamet-Ariobimo Rianti Dewi , Soedarsono Johny Wahyuadi , Suharno Bambang
Published: May 2013

Casting design is chosen by Soedarsono et al to maintain cooling rate in producing thin wall ductile iron (TWDI). Cooling rate should be maintained to prevent carbide formation. This paper discusses the effect of gating system design on microstructure and mechanical properties of 4 mm TWDI plate. A casting design based on vertical gating system is made to produce TWDI plates with the thickness of 1, 2, 3, 4, and 5 mm. This vertical system allows plates to function as runner which will helps in preventing premature solidification. Three designs were made. These designs are coded as T1, T2, and T3. These three designs were also used in making 1, 2, 3, and 5 mm TWDI plates of which the result has been published. Z-Cast is used to conduct a casting design simulation for filling flow and solidification. The result of flow simulation shows that the filling flow is resulted in two kinds. The result of solidification specifies that the 4 mm TWDI plates solidify in the third place. The result of the experiment highlights that in all of the designs, which have microstructure and consisted of nodule graphite in ferrite matrix, no trace of carbide and skin effect are formed. The length of skin effect varies in all of the designs. The highest nodularity is only 80% while nodule count is 931 nodules/mm2. Brinell hardness number for all of the design is beyond the standard given by JIG G5502. As for UTS, yield strength and elongation none of the designs exceeds the minimal standard. The result of the experiment does not confirm the result of the simulation. In sum, compared to the previous result, the curve trends of 4 mm TWDI plates look similar to 2 mm TWDI plates.
Dynamic Characteristic of Axially Moving Soft Sandwich Beam
Authors: Lv Hai Wei , Li Ying Hui , Li Liang
Published: May 2013

A new sandwich beam theory is proposed by introducing independent variables of the displacements of face sheets, middle plane of soft core according to the incompression in transverse direction of traditional sandwich beam theory. Based on Hamilton principal, the governing equation of the system is established. Galerkin truncation method was used to solve the governing equation. It was found that (1) the first mode of the system displays that it is consistent with the traditional sandwich beam theory; (2) the second mode of the system shows that the soft core is in the state of tension or in compression; (3) the third mode of the system displays that the upper part and lower part of soft core are in different state (tension or compression); (4) The incompressible model of sandwich beam is the special form of soft sandwich beam we establish in this paper.
Structural Design of Regenerator CA Nozzle in FCC Unit
Authors: Kim Hyun Sik , Lee Il Taek , Yang Sung Mo , Hong Dong Pyo
Published: May 2013

FCC Unit (Fluid Catalytic Cracking Unit) is a mechanical device used to convert bunker C oil into high quality gasoline. During the refining operation, pressure vessel of FCC unit operates in high-temperature and high-pressure environment. Careful structural analysis and design are necessary for such equipment.In this paper, FEA (Finite element analysis) of the FCC unit was performed to evaluate its structural stability. The equivalent stress of the FCC unit was investigated and compared against the ASME code design specifications.The area of high stress concentration with maximum stress higher than the prescribed value was analyzed locally to carefully evaluate the stress.CA nozzle in the FCC unit was found to have significant margins for factor of safety and was redesigned for weight reduction. Tensile test was carried out to verify the integrity of the welded parts. Tensile strength of the welded partssatisfies all design requirements.
Design on Ultrahigh Vacuum System with Titanium Pump
Authors: Zheng Jin Hua , Chao Yun Feng , Zhang Chong , Li Cong Hui
Published: May 2013

In order to meet the further requirements that study diamond-like carbon (DLC) films as rigid protective coating, a three-stage ultrahigh vacuum system composed of rotary vane pump and diffusion pump in parallel with TSP ( titanium sublimation pump) was designed mainly for getting limiting vacuum of 1.0×10-6Pa within 30 minutes in the vacuum chamber of about 0.23m3. The chamber is a horizontal cylinder supported by a saddle-shaped bracket and it has been proved to satisfy the requirements of strength and stiffness, it can be easy to get ultrahigh vacuum by TSP. Initiation pressure of the TSP was set to 10-3Pa vacuum after optimization analysis and the diffusion pump simultaneously was closed for the proper use. The system can be used as deposition equipment with the assistance of high and low vacuum measuring instruments and other accessories.
Stability Analysis of Arch Dam Abutment
Authors: Yang Ling Qiang , Gao Rui
Published: May 2013

Safe analysis of the progressive slide is used to estimate the stability of arch dam. The space stochastic parameters are surveyed through considering the relativity of parameter. The stability reliability analysis can be divided into element, sub-structure or sub-system, system.etc. From element to system calculate abutment’s ability. Sub-structure is composed by elements parallel connection. System is composed by sub-structures in series. The substructure method is applied to study the interaction between arch dam and its abutment. In this paper, the weakness part of abutment was found by cracking analysis of the progressive slide, and the safe evaluation was given.
An Experimental Study on the Performance of Fixed-End Supported PFRP Channel Beams under Flexure
Authors: Thumrongvut Jaksada , Seangatith Sittichai
Published: May 2013

The experimental investigation on the fixed-end supported PFRP channel beams subjected to three-point loading is presented. The objectives of this study are to evaluate the effects of the span on the structural behaviors, the critical buckling loads and the modes of failure of the PFRP beams, and to compare the obtained deflections with those obtained from the Timoshenko’s shear deformation beam theory equation in order to check the adequacy of the equation. The beam specimens have the cross-sectional dimensions of 152 43 10 mm with span-to-depth ratio ranging from 16 to 33. A total of twenty-two specimens were performed. Based on the experimental results, it was found that the loads versus mid-span vertical deflection relationships of the beam specimens are linear up to the failure, but the load versus mid-span lateral deflection relationships are geometrically nonlinear. The general modes of failure are the flexural-torsional buckling. Finally, the Timoshenko’s shear deformation beam equation can satisfactorily predict the vertical deflection of the beams within acceptable engineering error.
Research on Modeling and Optimization of a Dual Chamber Air Spring Vibration Isolation System
Authors: Zhang Cheng , Zhang Jian Fu , Feng Ping Fa , Yu Ding Wen , Wu Zhi Jun
Published: May 2013

To improve the vibration isolation performanceof an air spring system,the characteristics of the dynamic stiffness and damping of adual chamber air springwere first analyzed. A theoretical model ofa four dual chamber air springs system wasthen constructed,and through experimental verification,the theoretical and experimental curves showedthe same change trend.Based on the theoretical models, anobjective function used to optimize the structural parameters of an air springwas constructed. It was demonstrated that the vibration isolation performance of the air spring system was improved with the optimized parameters.
Numerical Simulation on Wave Force Acting on the Hollow Blocks
Authors: Chen Xue Feng , Yang Kang , Li Yu Cheng
Published: May 2013

In order to study the wave force acting on the hollow blocks structures locating at the permeable foundation under the regular wave flume, the wave tank is established basing on improved N-S Equations. And the moving boundary’s generating wave and wave absorption of momentum source are adopted in the numerical wave flume. It can also be simulated permeable foundation by porous media module. Then mathematical model can be constructed under the interaction between waves and hollow block when PISO is used to couple velocity and pressure fields. At the same time, the numerically calculated results of the wave force acting on the hollow blocks are compared with the experimental data in agreement. In conclusion, the variation of the wave force with incident wave height and period is obtained through the numerical calculation.
A New Concrete Failure Phenomena Due to Sulfate Attack
Authors: Wang Yan , Gao Rui , Zhang Hong Wu , Yang Ling Qiang
Published: May 2013

Based on more than 30 Km field survey, many samples has been got from sluice pier which is collapsed due to sulfate attack. The microstructure of sample and mineral component of separated material was analysis by X-ray diffraction (XRD) and scanning electron microscope-energy dispersion X-ray analysis (SEM-EDAX). The test shows the failure mechanism is contact dissolution associating sulfate attack. The contact dissolution gave chance to sulfate attack. The concrete expand due to sulfate attack accelerate contact dissolution. So concrete can be failure quickly.
SbVO4-TiO2 Cation Deficient Photocatalyst: Synthesis and Photocatalytic Investigation
Authors: Rahimi Rahmatollah , Moghaddas Masoumeh Mahjoub , Zargari Solmaz
Published: May 2013

For the first time antimony vanadium oxide-TiO2(SbV-T) nanocomposite was synthesized via sol-gel method to improve the photocatalytic efficiency of TiO2. The samples were characterized by FT-IR, XRD, SEM, EDX, and DRS. To investigate the photocatalytic activity of the samples, the photodegradation of methyl orange was carried out under visible light irradiation with pure TiO2, SbVO4, and SbVO4-TiO2nanocomposite. The SbV-T photocatalyst exhibited higher visible light driven photocatalytic efficiency to degrade MO dye. Furthermore the effect of SbVO4 and cationic vacancies in the photocatalytic activity of the SbV-T sample are described.
Synthesis of Mesoporous V-TiO2 with Different Surfactants: The Effect of Surfactant Type on Photocatalytic Properties
Authors: Rahimi Rahmatollah , Moghaddas Masoumeh Mahjoub , Zargari Solmaz , Rahimi Rahim
Published: May 2013

Mesoporous vanadium doped titania (V-TiO2) photocatalyst was synthesized with the use of a new surfactant (Gemini) for the first time. In order to investigate the surfactant effect on the photocatalytic activity of catalysts, different surfactants containing Gemini, pluronic F127, pluronic P123, CTAB, Hexadecylamine and PEG 6000 were used in the preparation of mesoporous V-TiO2photocatalyst as a templating agent. The catalysts were characterized by FT-IR, XRD, SEM, EDX, nitrogen adsorption-desorption isotherm, and DRS. The nanosized V-TiO2 with Gemini surfactant (V-TiO2(G)) exhibited the highest visible light driven photocatalytic efficiency for degrading MO dye. The results showed that the surfactant type played an important role on the structure and photocatalytic activity of the samples.
Model Experiments with New Lance for Pneumatic Powder Injection
Authors: Jezierski Jan , Janerka Krzysztof
Published: May 2013

The paper presents the results of model experiments with new lance design. The lance was invented in Silesian University of Technology, Department of Foundry. It is dedicated for the pneumatic powder injection into liquid metal bath without lance submersion. The situation like that is common for small molten alloy volume when the problem of temperature decrease is significant. In such case the carrier gas introduction into metal as well as cooling with gas blowing onto metal bath surface should be avoided. The new lance was equipped with four parallel slots made on its outlet and a flange. This design causes the carrier gas evacuation before it reaches the molten metal surface. The article presents the model experiments made with use of the device for the diphase gas-powder jet forces recording. The comparison of two lances: normal steel pipe and this of new design was presented in the article, too.
Synthesis of Surface Imprinted Polymer Microspheres with Ultrathin Polymer Shells via Surface-Initiated Iniferter Polymerization
Authors: Song Ren Yuan , Hu Xiao Ling , Li Ji , Guan Ping
Published: May 2013

A simple and effective approach was proposed to synthesize uniform surface imprinted polymer microspheres via surface-initiated iniferter polymerization. The chloromethyl groups were firstly introduced onto the surface of the polystyrene microspheres by a one-step dispersion polymerization. After that the photosensitive iniferter groups were modified by the reaction of the polystyrene microspheres surface-bound chloromethyl groups with N, N-diethyldithiocarbamate sodium. The grafting step was then carried out in a stirred solution of polystyrene microspheres containing surface-initiated iniferter in the presence of template molecules (glutathione, GSH), functional and cross-linking monomers. The synthesized surface imprinted polymer (GSH-MIP) microspheres were characterized using SEM and FT-IR. The GSH-MIP microspheres were spherical in shape, and showed homogeneous polymer layer and high encapsulation efficiency. The rebinding properties of GSH for GSH-MIP was evaluated by carrying out batch rebinding tests, the obtained GSH-MIP shows faster mass transfer and higher binding amounts rate toward template than non-imprinted polymer (NIP).
Synthesis and Properties of Ionogels Based on 1-vinyl-3-alkylimidazolium Tetrahalogenidoferrate (III) [VAIM][FeClnBr4-n] and PMMA
Authors: Tang Yi Mei , Hu Xiao Ling , Qian Li Wei , Guan Ping
Published: May 2013

The paramagnetic ionic liquid (IL) 1-vinyl-3-alkylimidazolium tetrahalogenidoferrate (Ⅲ) [VAIM][FeClnBr4-n] (A= n-butyl, n-pentyl, n-hexyl; n=3,4 or 2, 3,4.) has been used in the synthesis of paramagnetic [VAIM][FeClnBr4-n]/PMMA ionogels. The thermal stability for the ionogels increases signiﬁcantly compared with [VAIM][FeClnBr4-n] and PMMA. Magnetic susceptibility measurements were carried out in the temperature range 1.8 K–300 K. The Curie–Weiss temperature is -0.989 K, -0.669 K and -0.169 K, respectively as the alkyl chain to 3 position of imidazole ring elongate. The magnetic properties are similar to those reported for the pure IL and the self-made [VAIM][FeClnBr4-n] and are not influenced by the incorporation of paramagnetic [VAIM][FeClnBr4-n] into the PMMA matrix. The magnetic ionogel is thus an interesting material combining the mechanical properties of the polyer with the functionality of the magnetic IL, such as magnetism.
Design of Al2O3/CoAlO/CoAl Porous Ceramometal for Multiple Applications as Catalytic Supports
Authors: Andreev Andrey S. , Tikhov Serguey F. , Salanov Aleksey N. , Cherepanova Svetlana V. , Lapina Olga B. , Bolotov Vasiliy A. , Tanashev Yuriy Yu. , d’Espinose de Lacaillerie Jean Baptiste , Sadykov Vladislav A.
Published: May 2013

Porous ceramometal Al2O3/CoAlO/CoAl was studied by set of physicochemical techniques such as XRD, SEM, internal field59Co and27Al MAS NMR, and porosity measurements. They revealed the cermet containing three parts. First, cobalt-free large porous alumina particles which surrounded by the second oxide part representing spinel CoxAl3-xO4(x=1,2,3) oxides. And third, oxygen-free metallic part consists of cobalt metal particles covered by Co-Al oxide protecting the metallic part from oxidation. Porosity measurements ascertained high porosity (60%) and good SSA (122 m2/g). Also the enhanced adsorption of microwaves due to metallic particles randomly distributed in oxides was found.
Electromagnetic Cold Crucible Technology Applied for Producing Big-Sized γ-TiAl Based Ingots with Directional Growth Structure
Authors: Ding Hong Sheng , Nie Ge , Wang Yong Zhe , Chen Rui Run , Guo Jing Jie , Fu Heng Zhi
Published: May 2013

Developing high performance aero-engines usually depends on the development of new candidate materials with charming properties such as relatively light-weight, good high temperature strength and environmental resistance. Fortunately, γ-TiAl alloys were followed into this catalogue that they offer a significant potentiality for weight savings. Recently, in order to improve their low room temperature plasticity, a motive technology called electromagnetic cold crucible directional solidification technology for preparation γ-TiAl alloy ingots with directional growth structure was put forward by our group. By the approach, TiAl ingots with controllable lamellar structures and less impurity contaminations are obtained. Typically, Ti-46Al-0.5W-0.5Si and Ti-47Al-2Cr-2Nb were performed with respect to compositions and solidification parameters. As a result, Ti-46Al-0.5W-0.5Si DS-samples exhibit good combination of mechanical properties at room temperature in TS of 500MPa and EL of 2% in average. Meanwhile TS of DS Ti-47Al-2Cr-2Nb reaches 650 MPa and EL exceeds 3%.
Economic Surface Treatment of Ti-Alloys to Improve their Resistance against Environmental High Temperature Attack
Authors: Donchev Alexander , Schütze Michael , Kolitsch Andreas , Yankov Rossen
Published: May 2013

High temperature Ti-alloys are usually sophisticated and hence expensive. To allow the use of cheaper alloys at elevated temperatures an economic and easy to apply procedure was developed to improve their high temperature capability. The treatment consists of a combination of Al-enrichment in a shallow surface region plus additional fluorination. The Al-enrichment at elevated temperatures leads to the formation of intermetallic TiAl-phases. These phases improve the oxidation resistance of Ti-alloys but not to a sufficient extent. An additional fluorine treatment of the Al-enriched surface leads to the formation of a protective alumina scale due to the fluorine effect. In this paper results from high temperature exposure tests performed on different Ti-alloys without any treatment and with a combination of Al-treatment plus fluorination are presented. The results are discussed in the view of the use of the optimized Ti-components for several high temperature applications.
There is Low Cost Titanium Componentry Today
Authors: Withers J.C. , Shapovalov V. , Storm R. , Loutfy R.O.
Published: May 2013

In spite of titanium’s excellent combinations of lightweight, mechanical properties, and corrosion resistance it has been excluded from many applications because of its high cost in fabricated componentry. The major cost to produce a titanium alloy component is the processing of the sponge into alloy plus the several processing steps for fabricating the final finished component. If low cost titanium is to become a reality, the cost of post sponge processing to final finished components must be dramatically reduced. Processing to convert sponge directly in one step to an alloyed near net shape low cost component has been demonstrated. The mechanical properties are equivalent to better than standard processed wrought titanium. Example, automotive components and other applications that confirm titanium componentry at substantially lower cost than standard processing will be provided.
Development of Low Cost and Low Elastic Modulus of Ti-Al-Mo-Fe Alloys for Automotive Applications
Authors: Li Cheng Lin , Ye Wen Jun , Mi Xu Jun , Hui Song Xiao , Lee Dong Geun , Lee Yong Tae
Published: May 2013

Ti-Al-Mo-Fe alloys were developed as low cost beta Ti alloys for automotive springs, and designed based on Molybdenum equivalency and Bo-Md molecular orbital method. Low priced Mo-Fe master alloys were introduced as alloying elements for the cost and elastic modulus reduction. Eight Ti-Al-Mo-Fe alloy candidates were pre-designed according to the Bo-Md method. Primary laboratory scale ingots were thus melted by ISM (Induction Skull Melting). After primary property evaluation, the Ti-2Al-9.2Mo-2Fe alloy was optimized finally and large scale ingot was made by VAR for further property evaluation. Resultantly, it shows that the alloy has lower elastic modulus (60-70 GPa) and good tensile properties in the solution condition, and compares well with the other developed commercial beta alloys.
The Development of a Ti-6Al-4V Alloy via Oxygen Solid Solution Strengthening for Aerospace & Defense Applications
Authors: Jones Tyrone L. , Kondoh Katsuyoshi , Mimoto Takanori , Nakanishi Nozomi , Umeda Junko
Published: May 2013

The high cost of titanium has historically prevented widespread use in military ground vehicles. Two strategies to make this material more cost effective and viable are to reduce the cost of titanium armors or to improve the ballistic performance of titanium and reduce the amount of material required. This paper investigates the latter strategy. Mixtures of titanium powders and TiO2 particles were employed as starting materials and consolidated by spark plasma sintering (SPS) and hot extrusion. The content of TiO2 particles was 0~1.5% of the mass mixture. Solidification of oxygen atoms (from TiO2 particles) into Ti matrix occurred at 1073K for 1800 seconds in a vacuum. Tensile testing showed that Tensile Strength (TS) and Yield Strength (YS) increased in proportion to TiO2 content but elongation decreased slightly with increased TiO2 content. Extruded pure Ti powder material with 1.5% TiO2 particles produced 1040 MPa TS, 902 MPa YS and 25.1% elongation when tested. When using Ti-6Al-4V (Ti-64) alloy powders with 0.5% TiO2 particles, the final extruded Ti-64 powder bars with oxygen solid solution showed 1226 MPa TS and 22.7% elongation. Initial ballistic evaluation showed the Ti-64 powder bars with 0.5% TiO2 particles yielded a marked improvement over the conventionally rolled Ti-64 alloy plate.
Research and Development of Low-Cost Titanium Alloys for Biomedical Applications
Authors: Niinomi Mitsuo , Nakai Masaaki , Hieda Junko , Cho Ken , Akahori Toshikazu , Hattori Tomokazu , Ikeda Masahiko
Published: May 2013

β-type titanium alloys comprising low cost elements such as Fe, Mn, Cr, Sn, Al, O and N and having low Young’s modulus are currently being developed. Examples of such alloys include Ti-10Cr-Al, Ti-Mn, Ti-Mn-Fe, Ti-Mn-Al, Ti-Cr-Al, Ti-Sn-Cr, Ti-Cr-Sn-Zr, Ti-(Cr, Mn)-Sn, and Ti-12Cr. Ti-5Fe-3Nb-3Zr belongs to that class of titanium alloys in which rare metals such as Nb, Ta, and Zr have been reduced using Fe. Ti-5Fe-3Nb-3Zr has a Young’s modulus of around 76 GPa and has greater strength than that of Ti-6Al-4V ELI for biomedical applications. The characteristics of Ti-5Fe-3Nb-3Zr and other low-cost beta-type titanium alloys with low Young’s moduli are discussed from the viewpoint of biomedical applications.
Fracture Toughness of Powder Metallurgy and Ingot Titanium Alloys – A Review
Authors: Singh Ajit Pal , Gabbitas Brian , Zhang De Liang
Published: May 2013

Powder metallurgy (PM) is potentially capable of producing homogeneous titanium alloys at relative low cost compared to ingot metallurgy (IM). There are many established PM methods for consolidating metal powders to near net shapes with a high degree of freedom in alloy composition and resulting microstructural characteristics. The mechanical properties of titanium and its alloys processed using a powder metallurgical route have been studied in great detail; one major concern is that ductility and toughness of materials produced by a PM route are often lower than those of corresponding IM materials. The aim of this paper is to review the fracture toughness of both PM and IM titanium alloys. The effects of critical factors such as interstitial impurities, microstructural features and heat treatment on fracture toughness are also discussed
Development of a Continuous Process to Produce Ti via Metallothermic Reduction of TiCl4 in Molten Salt
Authors: van Vuuren D.S. , Oosthuizen S.J. , Swanepoel J.J.
Published: May 2013

After evaluating many different routes to produce titanium, the CSIR of South Africa selected a process to produce titanium powder continuously via metallothermic reduction of TiCl4 in molten salt. The project risks are being managed using the well-known STAGE/GATE method. The first two stages, viz, Route Selection and Preliminary Assessment have been completed and the next stage entailing campaigns extending over several days of uninterrupted operation, producing titanium at a rate of about 2 kg/h has recently begun. The rationale for selecting the process route is briefly reviewed and key process problems that had to be solved before embarking on scale-up and measures to do so are explained. Specific problems are: • Feed line blockages, • Titanium product formation and adherence to reactor internals, • Agglomerate formation; and • Production of very fine particles. Lastly the planned schedule and current status of the project are discussed.
Comparison of Microstructure and Properties of Ti-6Al-7Nb Alloy Processed by Different Powder Metallurgy Routes
Authors: Bolzoni Leandro , Hari Babu N. , Ruiz-Navas Elisa Maria , Gordo Elena
Published: May 2013

The Ti-6Al-7Nb alloy was specially developed to replace the well-known Ti-6Al-4V alloy in biomedical applications due to supposed cytotoxicity of vanadium in the human body. This alloy is normally fabricated by conventional ingot metallurgy by forging bulk material. Nevertheless, powder metallurgy techniques could be used to obtain this alloy with specific properties. This is because by changing the processing parameters, such as the sintering temperature, it is possible to vary the porosity level and to tailor the final properties. This work deals with the production of the Ti-6Al-7Nb alloy by means of the master alloy addition variant of the blending elemental approach. The powder is processed by means of different powder metallurgy routes considering diverse processing conditions for each method. The materials are characterised in terms of microstructural features, relative density and hardness. Homogeneous microstructures as well as properties comparable to those of the wrought alloy are generally obtained.
Mechanical Properties of Single-Melt PAM Processed Ti-6Al-4V Forgings
Authors: Guclu Mustafa
Published: May 2013

Ti-6Al-4V pancakes were manufactured by alpha-beta forging using single-melt (SM) plasma arc melt (PAM) billet stock at three oxygen levels, 0.16, 0.20 and 0.24 wt%, along with a standard double vacuum arc remelted (2XVAR) billet stock at 0.17 wt% oxygen for baseline comparison. Mechanical properties of forgings in the mill-, recrystallization- and beta-annealed conditions were then characterized by microstructure examination, tensile, smooth bar axial fatigue and fracture toughness testing in radial orientation. The effect of oxygen content on mechanical properties of the forgings was assessed. All SM PAM forgings exhibited slightly higher tensile and fatigue strength compared to those of 2XVAR. The fracture toughness values decreased with increasing oxygen content. Microstructures of all forgings were similar to those of conventional alpha-beta forgings. The data presented in this paper can be useful to designers in their efforts to introduce low-cost SM PAM Ti-6Al-4V (Ti-6-4) alloy forgings into various U.S. defense applications.
Phase Constitution and Heat Treatment Behavior of Low Cost Ti-Mn System Alloys
Authors: Ikeda Masahiko , Ueda Masato , Imaizumi Kaoru , Niinomi Mitsuo
Published: May 2013

This paper is a review of results for Ti-Mn [1], Ti-Mn-Al [2] and Ti-Mn-Fe [3] alloys that have been previously published. Titanium alloys, especially beta-type titanium alloys, have high specific strength, excellent corrosion resistance and good biocompatibility. Unfortunately, applications of titanium alloys are limited by their relatively higher cost. One reason is the use of rare and expensive metallic elements, such as vanadium and molybdenum, as a beta stabilizer. In order to reduce the cost, inexpensive and abundantly available metallic elements should be used as beta stabilizers. Manganese was adopted as a beta stabilizer because it is an abundant metallic element in the Earth’s crust and is relatively low in cost. The heat treatment behavior of Ti-Mn, Ti-Mn-Al and Ti-Mn-Fe alloys was investigated through electrical resistivity and Vickers hardness measurements, X-ray diffraction measurements to identify phase constitution, and observations using a light microscope [1], [2] and [3].
Cost Effective Developments for Fabrication of Titanium Components
Authors: Imam M. Ashraf , Froes F.H. Sam , Reddy Ramana G.
Published: May 2013

The major reason that there is not more widespread use of titanium and its alloys is the high cost. In this paper, developments in one cost effective approach to fabrication of titanium components - powder metallurgy - will be discussed under various aspects of this technology. The aspects to be discussed are the blended elemental approach, pre-alloyed techniques, additive layer manufacturing, metal injection molding, spray deposition and microwave sintering. A brief review of a number of low cost powder production processes is also presented.
The Production of Titanium Alloy Powder
Authors: Withers J.C. , Shapovalov V. , Storm R. , Loutfy R.O.
Published: May 2013

Titanium alloy powder provides manufacturing variants to produce a variety of titanium intermediate materials and final products. However, titanium alloy powder is quite expensive at fifteen to thirty times the cost of sponge thus limiting the utilization of titanium powder to produce titanium products. The standard state-of-the-art processing to produce alloy powder results in very high cost of alloy powder. Three new processes have been demonstrated to produce titanium alloy powder at a cost of only 2-5 times the typical cost of sponge. The processes are (1) one step melting of sponge/alloying and gas blowing alloy powder, (2) metallothermic reduction of mixed chloride precursors to produce alloy powder and (3) electrolytic reduction in a fused salt of mixed alloying (TiCl4-AlCl3-VCl4) chlorides. These processes have beeSubscript textn demonstrated to produce low cost titanium alloy powder which can serve as feeds for the variant manufacturing processes to produce low cost titanium products.
The TiRO™ Process for the Continuous Direct Production of Titanium Powder
Authors: Doblin Christian , Freeman David , Richards Matthew
Published: May 2013

The CSIRO is developing the TIRO™ process for the continuous direct production of titanium powder. The process comprises two stages. The first stage is a fluidised bed reactor (FBR) in which TiCl4 is reacted with magnesium powder to form solid magnesium chloride particles about 350 µm in diameter in which micron sized titanium particles are dispersed. The second stage is a continuous vacuum distillation operation where the titanium is separated from the magnesium chloride and sintered to form a friable “biscuit”. The biscuit comprises porous titanium spheres about 250 µm in diameter which can be liberated by very light grinding. The overall process has a throughput of 0.2 kg/h Ti, limited by the vacuum distillation unit and is being scaled up. The process has generated Ti powder with ≤0.25 wt% O and < 200 ppm Cl and meets CP2 specifications. Ring grinding the vacuum distilled product for short periods reduced the particle size, however longer grinding times caused agglomeration of the particles. Ring grinding in air resulted in a large increase in oxygen concentration
Processing of Titanium Powder into Consolidated Parts & Sheet
Authors: Mangabhai Damien , Araci Kerem , Akhtar M. Kamal , Stone Nigel A. , Cantin Delphine
Published: May 2013

The processing of titanium powder has been presumed to have potential to reduce the cost of final parts. The non-melt routes to efficient powder processing require consistent flow, adequate tap density and minimal pick-up of interstitial contaminants. The powder produced by the continuous sodium reduction of titanium tetrachloride has a coral-like morphology and low tap density. In order to achieve the potential of low cost parts, the powder will need to be modified to match the optimum feed conditions of the particular processing technique. The approaches to control interstitial pick-up will be discussed in the context of manufacturing technology: contribution of raw materials (10%), passivation (60%) and densification (30%). A comparison of densification with a change of milling fluid media (argon to water will be made with the unexpected decrease in oxygen pick-up when using water). Powder spheroidization via gas atomization of Armstrong Process® powder will be discussed. The product forms where the advantages of using powder can be exploited have to be carefully selected. Sheet is one such form: the results of using titanium powder to directly make titanium sheet will be presented.
Effect of Powder Compact Holding Time on the Microstructure and Properties of Ti-6Al-4V Alloy Produced by Powder Compact Extrusion of a Powder Mixture of HDH Titanium and Al-V Master Alloy
Authors: Yang Fei , Zhang De Liang , Gabittas Brain , Lu Hui Yang
Published: May 2013

Ti-6Al-4V (wt%) alloy rods were prepared successfully using a low-cost method that combines mixing HDH titanium, elemental aluminum and Al-V master alloy powders and powder compact extrusion. The microstructure and mechanical properties of Ti-6Al-4V alloy and the effects of powder compact holding time on them were investigated. The results showed that powder compact holding time had a significant effect on the microstructure and mechanical properties of the extruded Ti-6Al-4V alloy rods. With increasing powder compact holding time from 2 to 10 min., the microstructure of the extruded rods became more homogeneous, and their UTS decreased from 1300 to 1215MPa and the elongation to fracture increased from 7.1 to 10.2%. The tensile properties of the Ti-6Al-4V alloy rods produced by powder compact extrusion of the powder mixture are comparable to those of Ti-6Al-4V alloy produced by ingot metallurgy and thermomechanical processing.
Consolidation of Blended Titanium/Magnesium Powders by Microwave Processing
Authors: Imam M. Ashraf , Bruce Ralph W. , Feng Jerry , Fliflet Arne W.
Published: May 2013

Mg-Ti alloys are attractive for structural applications because of low density and improved corrosion resistance by selective oxidation including hydrogen storage and switchable mirror applications. Titanium has a melting point (1670°C) that greatly exceeds the boiling point of magnesium (1090°C) and therefore, alloying of Mg and Ti by conventional methods is extremely difficult. Secondly, the solubility of Ti in liquid Mg is very low and it is difficult to extend solubility by rapid solidification. Physical vapor deposition by electron beam deposition and magnetron co-sputtering has been used to extend the solubility of Ti in Mg. Mechanical alloying and anvil-cell processing at extreme temperatures and pressures have also used to enforce alloying of Mg with Ti. The present paper deals with the consolidation of blended magnesium-titanium powders by microwave heating, an approach that appears highly cost effective.
The Effects of Lubrication on the Density Gradient of Titanium Powder Compacts
Authors: Lou Jia , Gabbitas Brian , Zhang De Liang
Published: May 2013

In order to investigate the role of lubrication on the density gradient of titanium powder, a coloured layer method was employed. HDH titanium powder mixed with 0-1wt% stearic acid (SA) or magnesium stearate (MgSt) was cold compacted under different pressures. Coloured and uncoloured powders were used to give different layers in the die before compaction. The in situ density of different sections was calculated by measuring the height of the different layers. By using this method, the role of lubrication on the density gradient of titanium powder was experimentally measured. It was found that 0.3wt% of lubricant significantly improves the density variation, but further additions give only a slight improvement. An addition of 0.6wt% of SA provides an optimum density variation. The sintering results show that by using a very small amount of lubricant during processing there are no significant amounts of residual contaminants remaining in the Ti alloy.
Parameters Optimization of γ-Ti-46.6Al-1.4Mn-2Mo Alloy by Hot-Pressing Sintering and its Microstructures
Authors: Li Xu Guang , Lu Hui Min , Wang Pan Pan
Published: May 2013

In order to obtain the maximum relative density of γ-Ti-46.6Al-1.4Mn-2Mo alloy, the effects of the sintering temperature, heating preservation time and compacting force prepared by hot pressing were studied using Back Propagation (BP) Neural Network. The process parameters were optimized by Genetic Algorithm (GA) contributed by the use of Matlab. The results show that the optimum preparation process for Ti-46.6Al-1.4Mn-2Mo alloy are hot-pressing sintering temperature of 1374oC, heating preservation time of 291 min, compacting force of 37Mpa. The relative density of Ti-46.6Al-1.4Mn-2Mo alloy prepared under the condition is 96.11% (predicted value is 96.87%) with the relative error was only 0.78%. The microstructures of Ti-46.6Al-1.4Mn-2Mo alloy are studied by X-ray, optical microscope and SEM.
Study on Raman Spectra of Zinc Gluconate under Effect of Different Solvent
Authors: Sun Xiu Ping , Yu Zai Chao
Published: May 2013

Raman spectrum is a kind of characteristic spectrum. The information of molecular vibration and rotation can be obtained by studying Raman spectrum. Raman spectrum will be changed because of molecular interaction under effect of different solvent. We selected zinc gluconate as the object of research. Zinc gluconate is dissolved respectively in ethyl chloride, benzene, ring of ethane，chloroform, acetic acid, ethylene oxide, n-propanol, n-butanol solution, and Raman spectra were tested. The change of molecular internal structure and the interaction of molecular functional groups are studied by means of measuring Raman frequency shift, bandwidth, and light intensity. Thus, the information of solute structure change can be obtained. Experiments show that when zinc gluconate dissolved in the organic solvent, molecular gap became larger, its velocity increased, and stretching vibration of associating OH key group became strong. Methylenes in polar and non-polar molecule interact, and the polarization changed. In different polar solvents, Raman spectra had different changes. When the bond length increases，the stretching vibration frequency of molecules moves to the direction of low frequency. It produces red shift instead of blue shift. The results of this paper provide a basis to study molecular interactions further.
Automated Finishing of Diamond Turned Dies for Hard X-Ray and EUV Optics Replication
Authors: Beaucamp Anthony T.H. , Namba Yoshiharu , Freeman Richard R.
Published: May 2013

Ultra-precision diamond turning can deliver very accurate form, often less than 100nm P-V. A possible manufacturing method for thin Wolter type-1 mirrors in hard X-ray space telescopes thus involves generating electroless nickel plated mandrels by diamond turning, before coating them with a reflective film and substrate. However, the surface texture after turning falls far short from the requirements of X-ray and EUV applications. The machining marks need to be removed, with hand polishing still widely employed. There is thus a compelling need for automated finishing of turned dies. A two step finishing method is presented that combines fluid jet and precessed bonnet polishing on a common 7-axis CNC platform. This method is capable of finishing diamond turned electroless nickel plated dies down to 0.28nm rms roughness, while deterministically improving form error down to 30nm P-V. The fluid jet polishing process, which consists of pressurizing water and abrasive particles for delivery through a nozzle, has been specially optimized with a newly designed slurry delivery unit and computer simulations, to remove diamond turning marks without introducing another waviness signature. The precessed bonnet polishing method, which consists of an inflated membrane rotated at an angle from the local normal to the surface and controlled by geometrical position relative to the work-piece, is subsequently employed with a novel control algorithm to deliver scratch-free surface roughness down to 0.28 nm rms. The combination of these two deterministic processes to finish aspheric and freeform dies promises to unlock new frontiers in X-ray and EUV optics fabrication.
Technical Analysis Method on Diffraction Grating Mechanical Scratching Based on Limited Elements and Cross Experiment
Authors: Zhang Bao Qing , Shi Guo Qiang , Shi Guang Feng
Published: May 2013

Quality of the groove shap made by original diffraction grating is the main factor to affect the diffraction efficiency .The process of diffraction grating scratch mainly depends on the experience of the operator. However, its shortage is time-consuming, difficult and waste. In order to overcome the issues mentioned above, the new method has been put forward in this paper: simulate the process of diffraction grating scratch by limited element analysis and cross experiment, find out the process factor that affects the quality of the groove by rang analysis and sort. This method provides the reference to the process design of mechanical scratch grating and instruction to the adjustment of the grating trial scratch .It has practical significance on improving the quality of mechanical grating.