bluuebunny/crossref_metadata_2025 huggingface dataset:
Observation of Hydrogen Distribution in a Eutectic Mg-Ni Alloy by the Silver Decoration Method
Authors: Saitoh Hideyuki , Shimpo Misato
Published: June 2010

The silver decoration method was applied to the Mg-11.3mol%Ni eutectic alloy to investigate hydrogen distribution in it. The plate specimens of the alloy were electrochemically hydrogen charged using NaOH aqueous solution at ambient temperature. The specimens were silver decoration treated using K[Ag(CN)2] solved KOH aqueous solution to visualize the hydrogen location as the location of the silver grain. An effect of Pt coating on the decoration process was also examined. The Pt coating has drastically decreased the undesirable precipitation of the silver grain that caused by the direct galvanic reaction between the specimen and the decoration solution. The observed hydrogen location on the hydrogen input side has not been the Mg phase but the Mg2Ni phase in the eutectic structure. The hydrogen location on the hydrogen output side has been also the Mg2Ni phase. It has been thought that hydrogen is preferentially absorbed in the Mg2Ni phase and penetrates into the specimen through the Mg2Ni phase.
Application of Quenching and Partitioning to Improve Ductility of Ultrahigh Strength Low Alloy Steel
Authors: Cao Wen Quan , Wang Cun Yu , Shi Jie , Dong Han
Published: June 2010

In this study Quenching and Partitioning (Q&P) as proposed by Speer was applied to improve the ductility of C-Mn high strength Low Alloy steel (HSLAs). Microstructural observations revealed a multiphase microstructure including first martensite, fresh martensite and retained austenite in the Q&P processed steel. During tensile process, the austenite volume fraction gradually decreased with strain increasing, suggesting the phase transformation induced plasticity for the Q&P processed steel. Ultrahigh strength about 1300-1800MPa and tensile elongation about 20% were obtained after Q&P processing at specific conditions, which is significant higher than that of ~10% of conventional martensitic steel. The the product of tensile strength to total elongation increased from 25 to 35GPa% with increasing carbon content in studied steel. This improved mechanical properties were related to the ductility contribution from TRIP effects of the retained austenite and strength contribution from the hard martensitic matrix. At last it was turned out that the Q&P process is a promising way to produce ultrahigh strength steel with relative high ductility under tailored heat treatment conditions for different micro-alloyed carbon steel.
Fabrication of (Al2O3-Al3Nb)/Al Composite Materials by In-Situ Reaction Using MA Processed Al/Nb2O5 Powder
Authors: Lee Hyun Bom , Tezuka Hiroyasu , Kobayashi Equo , Sato Tatsuo , Woo Kee Do
Published: June 2010

A planetary ball milling (PBM) technique was employed to fabricate mechanically alloyed (MA processed) Al-Nb2O5 composite powder. Nano or sub-micron sized Nb2O5 particles were homogeneously embedded in the Al particles after milling for various periods. None of cracks, by-products and pores were observed in the areas between embedded Nb2O5 particulates and Al matrix powder after milling. The sequence of the in-situ reaction was confirmed by DSC, XRD measurements, optical microscopy and EPMA. The specific temperature of the in-situ reaction was between 650 and 700°C. Al-based metal matrix composites (MMC) reinforced with the sub-sieve sized θ-Al2O3 particulates and Al3Nb intermetallic compound were successfully fabricated by the in-situ reaction process. The substituted Nb by the in-situ reaction was fully reacted with Al to form the Al3Nb intermetallic compound during sintering. A number of sub-sieve sized θ-Al2O3 particulates and Al3Nb intermetallic compound formed by the in-situ reaction between Al and Nb2O5 were homogeneously distributed in the Al matrix during sintering. Nano sized θ-Al2O3 particulates are preferentially distributed near the Al3Nb intermetallic compound and no by-products are formed in the interfaces with the Al matrix.
Torsion Textures Simulation by Considering Rigid Body Rotation
Authors: Liu Yan Dong , Yang Yi Qiao
Published: June 2010

In this paper, the torsional texture evolution of pearlitic steel wire is simulated by Full Constrains (FC) Taylor model. The simulation results indicate that a simple shear deformation can not explain the experiments results of torsion texture. Bring in additional rigid body rotation and rational shear deformation can emersion the torsion texture very well. The different deformation styles are imposed to the FC Taylor, a group of parameters is given to explain the torsion texture evolution.
A Study on Tool Wear of Sheet Metal Stamping Die Using Numerical Method
Authors: Wang Xuan Zhi , Masood Syed H.
Published: June 2010

Advanced high strength steels (AHSS) are increasingly used in sheet metal stamping in the automotive industry. In comparison with conventional steels, advanced high strength steel (AHSS) stampings produce higher contact pressures at the interface between draw die and sheet metal blank, resulting in more severe wear conditions, particularly at the draw die radius. The prediction of tool wear patterns for sheet metal stamping die is a highly challenging task as there are many control parameters involved in the production. This paper presents a numerical simulation methodology to analyse the influences of various control parameters on tool wear patterns of a sheet metal stamping die with different die radius arc profiles. The results of tool wear patterns provide informative guidelines for on-site production.
Back Bead Characteristics during Butt Welding of a Thick Plate for Various Backing Conditions
Authors: Kim Cheol Hee
Published: June 2010

In a welded structure, thick plates are joined by multi-pass welding in the butt joint. During the first pass of multi-pass welding, burn-through, lack of fusion, and incomplete penetration were readily found as weld defects. Accordingly, the backing condition should be carefully selected in welding of a thick plate, because improper backing conditions lead to weld defects. In the job site, a steel backing strip is usually adopted, although it reduces the fatigue strength. No backing conditions or removable backing is recommended to increase the fatigue strength, but selection of the proper backing and welding conditions is complicated. In this study, several backing methods, such as ceramic backing, water-cooled copper backing, and even the use of no backing, were investigated during GMA (Gas Metal Arc) welding of a thick steel plate. The gas metal arc welding conditions were established for each backing method, and the bead shape and mechanical properties were examined after welding.
Preliminary Investigation into Repair of High Strength Steel Using Laser Cladding
Authors: Mohammed Reza , Liu Qian Chu , Janardhana Madabhushi , Clark Graham
Published: June 2010

High-strength steels are used in several critical aerospace applications such as aircraft landing gear, primary structure and engine components. These steels, such as the AISI 4340 assessed here exhibit small critical crack sizes, and when they suffer in-service damage from impact or corrosion, repairing the damage is particularly challenging. One potential repair method is using laser assisted metal deposition (LAMD or ‘laser cladding’ LC), to rebuild the damaged region or the grinding depression remaining after the damage has been removed. The critical situations where these materials are used makes it essential that repairs do not introduce any degradation, such as microcracking, that could lead to failure in service. In this trial, 420 grade stainless steel cladding powder was used to produce a clad layer with both high strength and good corrosion resistance. The cladding was performed under various powder mass flow rates, traverse speeds, and laser powers. The clad thickness and the depth of the fusion zone varied, as expected, with all the cladding conditions. It was found that there was very little porosity, and importantly, no evidence of microcracking under any cladding condition. There were some small defects near the clad boundary, apparently associated with each clad pass. The absence of microcracking is a promising result, and the research will be continued to assess the effect of microstructure and defects on performance of the repaired plates.
Interfacial Properties Prediction of Liquid Iron-Si Inclusion-MgO Refractory
Authors: Pradhan Debabrata , Reddy Ramana G.
Published: June 2010

A thermodynamic model for the prediction of interfacial tension of liquid iron, inclusion and solid oxide substrate/refractory was evaluated. The combined Good’s and Young’s equations were used for high temperature liquid metal-solid oxide substrate-inclusion system to evaluate the interfacial tensions. The study predicts the liquid silicon (as model inclusion/impurity) adherence on the solid oxide substrate/refractory (MgO) in a liquid iron melt. The calculated results for interfacial tension between liquid iron-MgO values decreased from 1798 to 1026 ergs/cm2 as the temperature increases from 1823 to 1933 K, respectively. The Gibbs energy of adhesion for liquid silicon-MgO substrate was calculated shows that silicon adhesion to MgO substrate increases with increasing surface tension of liquid Fe/MgO and with decreasing temperature.
Materials Technology for PC-TPP in Green Economic Era
Authors: Kim Jeong Tea , Kong Byeon Gook
Published: June 2010

Coal fired power generation should be amalgamated with efficiency improvement technology of electric-power production and treatment technology of greenhouse gas in green economic era. The efficiency of fossil power plant can be achieved by increment of temperature and pressure of steam, and the performance improvement of the components. The improvement of temperature and pressure of live steam can be supported by the materials with high temperature strength and the excellent resistance to oxidation. Specially, verified materials have to be used in large quantities for both repair and replacement of steam facing components. The efficiency of newly constructed Pulverized Coal – Thermal Power Plant[PC-TPP] is higher than 42% at Ultra Super Critical[USC] conditions of 250~300 bar and 600~610oC. Recently, material technology has been developed to build PC-TPP of the steam condition of advanced USC with more than 46% efficiency. However, it is expected to have problems to economically manufacture in large quantities. Therefore, the paper explains the current the state of the art of materials technologies and the issues with the steam.
The Effect of Ti Addition on Phase Equilibria among Ni (A1), Ni3Al (L12) and Ni3V (D022) Phases
Authors: Hayashi Eiki , Kobayashi Satoru , Sato Kazuhisa , Konno Toyohiko J. , Kaneno Yasuyuki , Takasugi Takayuki
Published: June 2010

The effect of Ti addition on phase equilibria among Ni (A1), Ni3Al (L12) and Ni3V (D022) phases at 950 °C was investigated through TEM/EDS analysis on heat-treated alloys. The three-phase coexisting region of A1 + L12 + D022 was found to exist around the composition of Ni-4Al-19V (at. %) in the Ni-Al-V ternary system. With addition of Ti to the ternary system the three-phase coexisting region was shifted to the Ni-rich side. Ti partitioned most into the L12 phase and least into the A1 phase. These results suggest that the addition of Ti stabilizes the L12 and D022 phases against A1 phase, and raises the temperature of eutectoid reaction in the Ni3Al-Ni3V pseudo-binary system: A1 → L12 + D022.
Alloying Behavior of Ni3Nb, Ni3V and Ni3Ti Compounds
Authors: Sugimura Hotaruko , Kaneno Yasuyuki , Takasugi Takayuki
Published: June 2010

The site preference of ternary additions in Ni3X-type GCP compounds was determined from the direction of solubility lobe of the GCP phase on the experimentally reported ternary phase diagrams. In Ni3Nb (D0a), Co and Cu preferred the substitution for Ni-site, Ti, V and W the substitution for Nb-site, and Fe the substitution for both sites. In Ni3V (D022), Co preferred the substitution for Ni-site, Cr the substitution for both sites, and Ti the substitution for V-site. In Ni3Ti (D024), Fe, Co, Cu, and Si preferred the substitution for Ni-site, Nb, Mo and V the substitution for Ti-site. The thermodynamic model, which was based on the change in total bonding energy of the host compound by a small addition of ternary solute, was applied to predict the site preference of ternary additions. The bond energy of each nearest neighbor pair used in the thermodynamic calculation was derived from the heat of compound formation by Miedema’s formula. The agreement between the thermodynamic model and the result of the literature search was excellent. Both transition and B-subgroup elements have two possibilities, i.e., the case of substitution for Ni-site or the case for X-site, depending on the relative value of two interaction energies.
A Systematic Study on Iron Carbides from First-Principles
Authors: Kim In Gee , Rahman Gul , Jang Jae Hoon , Song You Young , Seo Seung Woo , Bhadeshia H.K.D.H. , Freeman A.J. , Olson G.B.
Published: June 2010

The formation enthalpy of a series of Fe-C carbides has been estimated using a first-principles approach. The Fe to C ratio dependence of the formation enthalpy is reasonable, but it is revealed that - and -carbides require an extraordinary environment to be able to form. Furthermore, an addition of substitutional solutes other than Fe and C should promote other carbides with different crystal structures. The analysis suggests further studies to discover the critical concentrations of alloying which stimulate the other carbides to become more stable.
Fretting Wear Resistance of ATW Cr3C2/Ni3Al Composite Hardfacing on IC6SX
Authors: Li Shu Suo , Wu Mei Ling , Sun Lu , Jiang Li Wu , Han Ya Fang
Published: June 2010

The fretting wear performance of surface wear-resistant Cr3C2/Ni3Al composite deposited onto IC6SX alloy by manual argon tungsten-arc welding was investigated in this study. The results showed that the welded substrate exhibits a very good performance in comparison to the unwelded substrate at 500°C and 800°C, with 51.5% and 57.8% decrease of the fretting sectional area respectively. However, the fretting sectional area of the welded substrate is larger than that of the unwelded substrate at RT indicating poor fretting resistance as the reinforce phases of the welding layer is harder and more harmful to the sample surface. Examination of the fretting surfaces indicated that both the welded and unwelded samples undergo gross slip at RT and 500°C, and partial slip at 800°C. Coefficient of friction (COF) results were given by the SRV-4 tester which shows that as the temperature goes up, the COF of samples became lower and more stable. The results showed that the COF of welded substrate is lower than that of the unwelded substrate most of the time.
Cobalt-Based Alloys for High Temperature Applications
Authors: Mahapatra Rabindra , Imam M. Ashraf , Lei C.S. , Feng C.R.
Published: June 2010

The isothermal oxidation behavior and thermal stability of a cobalt base alloy was investigated up to a period of 312 hr in air from 1000 to 1200°C. A comparison of oxidation behavior of this alloy with a conventional nickel-base superalloy (Inconel 713C) has been conducted in detail. This experimental alloy oxidizes by forming layers of Al2O3, Cr2O3, TiO2, CoO and traces of SiO2 with WO2 oxides on the surface of the specimen in contact with air. Scanning electron microscopy (SEM) was used to study the microstructure, morphology and compositions of oxides formed after the exposure. Thermal stability of the alloy after extended periods of exposures to air at 1000, 1100 and 1200°C was studied using transmission electron microscopy (TEM).
Study of a New Type High Strength Ni-Based Superalloy DZ468 with Good Hot Corrosion Resistance
Authors: Zheng Zhi , Liu Enze , Yu Yong Si , Zhu Yao Xiao
Published: June 2010

The mechanical property, hot corrosion resistance and phase stability of a new-type directional solidification nickel-base superalloy named DZ468 that was developed independently by Institute of Metal Research, Chinese Academy of Sciences were investigated in this paper.The rupture properties of DZ468 alloy are nearly the same as those of DZ4125 alloy and its hot corrosion resistance property nearly the same as that of IN738 alloy under the same conditions. There is no finding TCP phase in the DZ468 alloy after aging at 900°C for 1000h. DZ468 alloy displays excellent phase stability.
Oxidation Resistance of Innovative Carbon-Based Materials Results of ExtreMat
Authors: Moormann Rainer , Hinssen Hans Klemens , Schlögl Bärbel
Published: June 2010

Sufficient oxidation stability of advanced carbon based materials is a key feature for their application in fusion, fission, aerospace and chemical engineering. These materials were examined as part of the EU research projects ExtreMat and Raphael-ML. This paper discusses the presently available oxidation model, outlines its limits on basis of respective experiments and proposes improvements. Methods for oxidation protection of advanced carbon based materials as doping and coating with different components are discussed. Experimental oxidation results on EX10, a carbon fibre in SiC matrix, in air at high flow rates and high temperatures are presented.
Temperature Dependence of Compressive Deformation Behavior of Mg89Zn4Y7 Extruded LPSO-Phase Alloys
Authors: Hagihara Koji , Kinoshita Akihito , Sugino Yuya , Yamasaki Michiaki , Kawamura Yoshihito , Yasuda Hiroyuki Y. , Umakoshi Yukichi
Published: June 2010

Deformation mechanisms of Mg89Zn4Y7 (at.%) extruded alloy, which is mostly composed of LPSO-phase, was investigated focusing on their temperature dependence. The yield stress of as-extruded alloy showed extremely high value of ~480 MPa at RT, but it largely decreased to ~130 MPa at 300 °C. The decreasing rate of the yield stress could be significantly reduced, however, by the annealing of specimen at 400 °C, by suppressing the microyielding which is considered to occur related by the grain boundary sliding in restricted regions. The yield stress of the annealed specimens with random textures could be estimated by the Hall-Petch relationship by regarding the length of long-axis of plate-like grains as a grain size between RT and 300 °C. The yield stress of the annealed specimens maintained high values even at 200°C, but it also showed large decreases at 300 °C.
Thermal Stability and Mechanical Properties of Extruded Mg-Zn-Y Alloys with Long-Period Stacking Order Phase
Authors: Noda Masafumi , Kawamura Yoshihito
Published: June 2010

Magnesium alloys are very attractive in such applications as automotive and aerospace. However, the mechanical properties of Mg alloys are inferior to those of Al alloys, and this limits their range of applications. In the present study, effects of annealing on the mechanical properties and the thermal stability of the microstructure in LPSO Mg-Zn-Y extruded alloys were investigated. Even when elongation showed 10% with having maintained high strength to annealing temperature at 573 K for 3.6 ks, and this alloy extended annealing time for 1.0 kh, LPSO phase did bent and was able to confirm kink bands. On the other hand, α-Mg phase was fine structure without pronounced grain growth. In elevated temperature deformation of as extruded and annealed materials, LPSO phase did finely dispersed to α-Mg phase by grain boundary sliding of α-Mg phase, but fracture did not occurred in the interface between LPSO and α-Mg phases. Kink bands introduced in LPSO phase during plastic deformation and fine-grained α-Mg phase were important to obtained of high strength and ductility.
Effect of Minor Additions of Al and Si on the Mechanical Properties of Cast Mg-3Sn-2Ca Alloys in Low Temperature Range
Authors: Rao Kamineni Pitcheswara , Suresh K. , Hort Norbert , Kainer Karl Ulrich
Published: June 2010

The Mg-Sn-Ca alloys have shown superior creep properties compared to the creep resistant alloy AE42. In the present study, the effects of small amounts of Al and Si additions on the mechanical properties have been investigated on a Mg-3Sn-2Ca (TX32) alloy. The Al content in the selected alloys was 0.4 wt% and the Si content was varied from 0–0.8 wt% in steps of 0.2 wt.%. The alloys were cast in pre-heated permanent molds. Cylindrical specimens machined from the cast billets were tested in compression in the temperature range 25–250 °C at a strain rate of 0.0001 s–1. The alloy with 0.4 wt% Al shows an increased strength at all test temperatures compared with the TX32 base alloy. This is attributed to a solid solution strengthening of Al in Mg. The alloy with 0.4 wt% Al and 0.2 wt% Si has compressive strength that is closer to that of the TX32 alloy. However, increased additions of Si (from 0.4–0.8 wt%) reduce the strength, more significantly at higher temperatures.
Microstructure and Tensile Properties of an Mg-5Sn-5Zn Alloy
Authors: Zhou Ji Xue , Yang Yuan Sheng , Tang Shou Qiu , Tian Chang Wen
Published: June 2010

The microstructure and tensile properties at room temperature of as-cast, solution-treated and aged samples of a Mg-5Sn-5Zn (wt%) alloy are investigated. The microstructure of the as-cast sample consists of -Mg primary, Mg-MgZn eutectic, divorced eutectic Mg2Sn and secondary precipitation Mg2Sn. After solution treatment, all the MgZn particles and the majority of Mg2Sn phases are dissolved into the matrix and the tensile strength and the elongation of the alloy increase obviously. During aging process many fine particles precipitate which result in the improvement of the yield strength.
The Study on the Precipitation and Mechanical Properties of Steel with Copper
Authors: Li Chuang , Wang Xue Min , He Xin Lai , Shang Cheng Jia , He Yu
Published: June 2010

The properties and precipitation behavior of Cu-bearing steels have been investigated. The optical microscope and transition electron microscope were employed to study the influence of interrupted cooling and quenching temperature on the precipitation behavior. Also, the properties of samples with different quench processes were tested. The results show that when the steel is interruptedly cooled and quenched from 650-700°C, with the quenching temperature increasing the volume fraction of martensite becomes larger and the hardness becomes higher. When the microstructure is ferrite the second-phase precipitates occurs and they are proved copper-rich particles. However there are no obvious precipitates in martensite. The copper-rich second phase forms by the way of inter-phase precipitation.
Twinning Behavior in AZ31-B Polycrystal Texture Subjected to In-Situ Bending Test
Authors: Sato Itsuya , Miura Seiji , Mohri Tetsuo
Published: June 2010

A commercial Mg alloy, AZ31B, has been used widely. In the texture of AZ31B sheet, each grain has its c-axis almost parallel to the sheet normal. Therefore, at the bending process of the sheet, basal slip system can not accommodate an in-plane plastic strain which is perpendicular to the c-axis of each grain. It is known that {10―,12} twin can be formed by applying an extension strain parallel to the c-axis, which is equivalent to the a-axis compression strain. So in the bending deformation of the AZ31B sheet with a texture microstructure, it is expected that {10―,12} twinning occurs. In this study, an in-situ bending test of AZ31B sheet with a texture was conducted under a confocal scanning laser microscope to observe twinning by applying compression stress along a direction almost perpendicular to the c-axis of grains. In addition, EBSD techniques were used for the analysis of crystal orientations. The process of twin development observed by the in-situ bending test can be summarized as follows; with the increase of the deformation strain, the total area of twins increases. However, it is noted that the growth of twins is apparent while the number of twins is almost constant during plastic bending deformmation. EBSD analysis suggested that twinning behavior obey Schmid’s law even in the polycrystal.
Effect of Austenite on Drawing Limit of Ferrite-Austenite Dual Phase Wire
Authors: Lee Seung Hyun , Lee Hu Chul
Published: June 2010

The drawability of ferrite-austenite dual phase wires decreased with increasing volume fraction and decreasing mechanical stability of austenite. The interface of the martensite and ferrite was identified as the void nucleation site and the number density of voids increased with increasing austenite volume fraction. The plastic incompatibility at the interface was assumed to be the main reason for void nucleation. The ferrite-austenite dual phase steels could be drawn to a maximum true strain of 8.0 without intermediate heat treatment. The tensile strength of the drawn wires increased with increasing volume fraction of austenite or, in other words, with increasing volume fraction of transformed martensite.
In-Line Rolling of Aluminum Alloy Strip Cast by a High Speed Twin Roll Caster
Authors: Nakamura Ryoji , Hanada Shuuya , Kumi Sinji , Watari Hisaki
Published: June 2010

In-line rolling was operated on the as-cast strip cast by a vertical type high speed twin roll caster. The AA6022 and AA6111 strip was tested. The casting and rolling speed was 60m/min. Reduction was from 20% to 55%. The temperature of the rolling was within from 400oC to 450oC. The porosity and crack in the strip were improved by the in-line rolling. The in-line as rolled strip was cold rolled down to 1mm, and T4 heat treatment was operated. The microstructure of the strip, on which in-line rolling was operated, became uniform at thickness direction than the microstructure of the strip on which only the cold rolling was operated. The surface defects like the ripple mark and trace line of the nozzle were improved.
Technology of Molten Salt Electrolysis of Magnesium Chloride
Authors: Choi Mi Seon , Lee Chang Kyu , Lee Go Gi , Cho Sung Koo , Jung Jae Young
Published: June 2010

The electrolytic production of magnesium from magnesium chloride containing sodium chloride-rich melts has been studied using mono-polar cell, where originally designed in consideration of current efficiency and energy consumption. The magnesium was formed well at the surface of cathode and floated at the free surface of the molten salt, and chlorine gas was generated at the anode without any inverse reaction between the magnesium which is produced electrolysis process. The magnesium was collected about 200 g/hr by operating an optimized mono-polar cell with 500 A for 24 hours. The metallic magnesium produced from this study had a high purity with 99.92 %.
LCA Study of Rare Earth Metals for Magnesium Alloy Applications
Authors: Koltun Paul , Tharumarajah Ambalavanar
Published: June 2010

High strength properties combined with low density has made magnesium alloys a highly attractive structural material, in particular where weight savings is of concern. In air and ground transport these alloys are used as alternative material in place of heavier ferrous or aluminium alloys. In this respect, much research has been directed at developing and deploying superior magnesium alloys using rare earth elements (REEs), an example the Mg-RE (Ce, Y, Nd) alloys for drive train components. With the overall aim of ascertaining the environmental impact of employing REEs as alloying agents in producing superior Mg-RE alloys, it is paramount that a fundamental understanding of the environmental burden imparted by the extraction and production of REEs be determined. This study reports on such an assessment of REEs by conducting a detailed life cycle assessment (LCA) study of the environmental impact from mining to production of REEs.
Effects of Impurity Elements on Green Strength of Powder Compacts
Authors: Lim Ju Beom , Bettles Colleen J. , Muddle Barry C. , Park Nho Kwang
Published: June 2010

The green strength of a powder compact results from the mechanical interlocking of the irregularities on the particle surfaces. During compaction, particle rearrangement, plastic deformation and particularly surface deformation of powders occur. Titanium powder is susceptible to interstitial element contamination, which may lead to solid solution strengthening of the particles and/or the formation of non-metallic compounds on the surface. However, the influence of these various impurities, namely oxygen and nitrogen, on the green strength has not been investigated. This work investigates and quantitatively evaluates the factors influencing the green strength of the powder compacts. The indirect tensile test was applied for the determination of the green strength of the powder compacts, and test results were compared to that of a more conventional 3-point bending test. The substantial dependence of green strength on both the amount of impurity element in the core of the powder particles and the compaction pressure is demonstrated. The effect of the surface condition of the powder particles on green strength is also reported.
Phase Constitution and Heat Treatment Behavior of Ti-7mass% Mn-Al Alloys
Authors: Ikeda Masahiko , Ueda Masato , Matsunaga R. , Niinomi Mitsuo
Published: June 2010

Titanium exhibits many attractive properties. It is considered to be ubiquitous since it has the 9th-highest Clarke number of all the elements. However, the principal beta-stabilizing elements for titanium can be very expensive, making many titanium alloys expensive. Manganese is a beta stabilizer for titanium alloys and it is also considered to be ubiquitous since it has the 11th-highest Clarke number of all the elements. The behavior of Ti-Mn alloys during heat treatment has been investigated and it was found that in some alloys the isothermal omega phase is precipitated. Because this phase can lead to brittleness, it is very important to suppress its precipitation. Since it is well-known that aluminum suppresses isothermal omega precipitation, we investigated the effect of adding aluminum using Ti-7mass% Mn-0, 1.5, 3.0 and 4.5mass% Al alloys by performing electrical resistivity, Vickers hardness, and X-ray diffraction measurements. In solution-treated and water-quenched 0 and 1.5 alloys, only beta phase was identified, while hcp martensite and bate phase were identified in 3.0 and 4.5Al alloys. The resistivities at room and liquid-nitrogen temperatures were found to increase monotonically with increasing Al content. Isothermal  precipitation was suppressed by aluminum addition, while alpha precipitation was accelerated by Al addition.
Characterization of the Mechanical Behaviour of Both Fusion Zone and Base Metal of Electron Beam Welded TA6V Titanium Alloy
Authors: Huez Julitte , Buirette Christophe , Andrieu Eric , Perusin Simon , Audion Sylvain
Published: June 2010

The fusion zone of an electron beam welded Ti-6Al-4V alloy presents a ' martensitic structure which leads to a change of mechanical properties. Starting from two manufacturing processing routes for the alloy (1) a  processing followed by the weld (the reference microstructure), (2) an  processing followed by welding and a post weld heat treatment (PWHT), the microstructure can be adjusted to avoid local difference of strength, fatigue properties and impact toughness. This results from the optimisation of the process and of the PWHT. The present work investigates the mechanical behaviour and the damage mechanism of both base metal and fusion zone in regards to the microstructure and to the heat treatment parameters.
Characterisation of Cold Spray Titanium Coatings
Authors: Gulizia Stefan , Trentin A. , Vezzù S. , Rech Silvano , King Peter , Jahedi Mahnaz Z. , Guagliano Mario
Published: June 2010

Cold spray is a solid state spray deposition process utilizing a supersonic De Laval nozzle to accelerate fine particles to high velocities. Particles plastically deform on impact to the substrate and to each other to create dense well adhered structures. In this study, the microstructure and mechanical properties of cold spray Titanium coatings deposited using nitrogen gas at different gas temperature and pressure were examined. In general, it was found that gas-atomised CP-titanium powder is capable of producing dense coating structures on aluminium alloy (Al6061) substrates. The micro-hardness, oxygen and nitrogen content of the coatings were found to be slightly higher than powder in the as-received condition. It was also found the coating residual stress was purely compressive when cold spray is conducted at high gas pressure and temperature.
TEM Observation of Metastable Phases in Aged Al-Mg-Ge Alloys
Authors: Matsuda Kenji , Nakamura Junya , Yamamoto Keisuke , Kawabata Tokimasa , Uetani Yasuhiro , Ikeno Susumu
Published: June 2010

The purpose of study is to investigate aging behavior, crystal structures of metastable phase and relative frequency of metastable phases in aged Al-Mg-Ge and Al-Mg-Ge-Si alloys using high resolution transmission electron microscope (HRTEM), energy dispersive X-ray spectroscopy (EDS) and electron energy-loss spectroscopy (EELS). Every alloy included rod-shaped precipitate which is the same as the typical metastable pahse, ’, in Al-Mg-Si alloy. Except to Mg-rich alloys, the Type-A precipitate, which is a typical metastable phase in the excess Si type Al-Mg-Si alloys and popular at over aged condition, was confirmed as a large rod-shaped precipitates in those alloys. This behavior is probably depends on the ratio of Mg/Ge. Also, Mg, Si and Ge were detected from the ’-phase in Al-Mg-Ge-Si alloy by EELS. This means that the ’-phase in Al-Mg-Ge-Si alloy consists of these 3 elements including Si, not just Ge to form metastable Mg2Ge.
The Microstructure Characteristics and Wear Resistance of Rapidly Solidified Hypereutectic Al-Si Alloys
Authors: Li Ji Wen , Wang Ai Qin , Xie Jing Pei , Wang Wen Yan , Li Luo Li
Published: June 2010

Rapidly solidified hypereutectic Al-21Si was prepared by the single roller melt-spinning technique. The microstructure morphology characteristics and phase structures of the alloy were characterized using SEM, TEM and XRD technique. The results showed that the grains were refined and the micro-nano composite structures were formed under rapid solidification. The microstructure of the Al-21Si alloy was composed of micro-nanostructured α-Al phase and feather-needle-like eutectic α-Al+β-Si phase. The α-Al phase was the leading phase in the eutectic α+Si phase. The nucleation and growth of primary silicon are suppressed and primary silicon could not be precipitated. The hypereutectic Al-21Si alloy showed the hypoeutectic solidification microstructure. Wear resistance was improved obviously when the rapidly solidified and was five times higher than that of the traditional casting alloys.
Coordination of Rated Power of Wind Turbine with a Bar Graph of Wind Speed by Means of Flexible Control Algorithm of the Hydraulic Drive
Authors: Gubarev Aleksandr , Ganpantsurova Oksana
Published: June 2010

The paper considers an approach that enables increasing efficiency of wind turbine operation by sampling a rational correlation of generators number and parameters of equipment in structure of a hydrosystem. A flexible control algorithm for a system of power obtaining in STL language was developed. The algorithm considers peculiarities of wind turbine operation in conditions of variable airstream speed.
Modal Reduction and Analysis of Gyroscopic Systems
Authors: Orlikowski Cezary , Hein Rafał
Published: June 2010

The paper introduces the method of the modal reduction of systems that experience the Coriolis acceleration or gyroscopic effect component. In such cases corresponding system equations are non-self-adjoined. To solve the problem modal reduced model is built up for the system without Coriolis acceleration or gyroscopic effect terms. These phenomena are next included by application of any lumping technique. Hence, the final reduced model is a hybrid one, obtained by both lumping and modal methods of modelling.
Adaptation of the Expert System in Diagnosis of the Connection of the PLC User Interface System and A Field Level
Authors: Świder Jerzy , Hetmańczyk Mariusz Piotr
Published: June 2010

Authors of the paper focused on the problem of devising a concept of computer-aided diagnosis system of a centralized PLC control coupled with the distributed drive systems operated by frequency converters via the ProfiBus industrial network. It is worth emphasizing that the presented concept is useful in all automated systems characterized by the PLC centralized control. The paper provides the description of one of the several modules of dedicated software developed by the authors [6].
Computer-Aided Analysis of Piezoelectric Plates
Authors: Buchacz Andrzej , Wróbel Andrzej
Published: June 2010

Present paper is a continuation of author’s earlier publications on stacking of piezoelectric plates. Analysis effects are presented by schemes received on the basis of computer calculations. The program is used for creation and analysis of graphical characteristics of piezoelectric plates. The application allows generation of graphs for a single piezoelectric plate as well as for complex systems. An additional advantage is the ability to obtain the 3D graphs, in which the test graph characterizes the plate not only in terms of frequency but can also include other parameters such as the thickness of the plate. The application is written in numerical software "Matlab" in such a way that it is possible to run a program on any computer without the installed software. A necessary condition for the correct operation of the program is availability of “MCR Matlab Compiler Runtime” free library.
Modeling of Iron Wolf Howling
Authors: Slivinskas Vytautas , Šimonytė Virginija , Pyž Gražina
Published: June 2010

The purpose of the paper is to develop a model of iron wolf howling. The recorded live sounds of wolf howling are used in order to obtain parameters of the model. Spectral density of the recorded sounds is investigated by means of MUSIC method. A sum of quasipolynomials of the second order is applied as a model of wolf howling. The parameters of the model are estimated using short intervals of records (pitches). The parameters of the model are estimated by the modified Levenberg method. The final model is presented in a state space form.
Development of Mathematical Model of a Mechatronic System
Authors: Buchacz Andrzej , Płaczek Marek
Published: June 2010

This paper is a continuation of earlier publications of the authors related to the analysis of mechatronic systems including piezoelectric materials used as sensors or actuators
for stabilization and damping of mechanical vibration. It was demonstrated that only very accurate mathematical model of the system with the piezoelectric transducers and external electric circuit attached to a mechanical system like a beam or a shaft by a glue layer allows the engineers to design the system with required dynamic parameters. Geometrical and material parameters of all the components have to be taken into account because neglecting the influence of one of them results in erroneous analysis results [1-4]. The paper presents the improved mathematical model
of the considered mechatronic system. The assumption of pure shear of the connection layer is rejected during modeling and deformation of the layer is taken into consideration. The purpose of the reported enhancement of the mathematical model of the considered mechatronic system is to improve accuracy of computational results.
Numerical Application for Dynamical Analysis of Rod and Beam Systems in Transportation
Authors: Zolkiewski Sławomir
Published: June 2010

Author’s computer program for dynamical analysis of the systems in transportation is presented in the paper. The presented version of this software is the upgrade of the Modyfit application [7]. The program was developed from the previous one for application that enables to analyze and model damped systems in transportation.
Detection of Defects in Steel Ropes Using Dynamical Methods
Authors: Augustaitis Vytautas Kazimieras , Bučinskas Vytautas , Subačius Rimantas
Published: June 2010

Early defect detection and monitoring of rope systems constitute important safety requirements for equipment that employs ropes as single driving component, e.g. lifts, rope trains, etc. Quality characteristics of ropes are regulated by procedures of safety standards and are prescribed in safety standards of transportation machines, which are particularly stringent in the case of human elevating equipment. Many types of rope quality control are applied in practice but standard control procedure of such nonhomogeneous structures as ropes with electromagnetic methods are still not fully reliable, particularly in the case of broken wires in rope strands.
The paper presents a method for detection of the aforementioned rope defects using dynamic properties of a rope that is treated as a dynamic system. The proposed method enables to measure dynamic characteristics of a rope system and, based on obtained results, evaluate rope quality, determine the presence of broken strands and define cross-section of the defects. Analysis of dynamic properties is used in order to establish existence of a defect. Aim of such analysis is to determine some characteristic natural frequencies corresponding to broken strand and change of the lowest natural frequencies that represent the rope as a constrained system. The paper also addresses the issues of equipment and methodology required for defect detection in ropes together with the necessary conditions. Final conclusions are formulated with regard to possibility of implementing the proposed method in real working conditions.
In-Pipe Modular Robotic Systems for Inspection and Exploration
Authors: Tătar Mihai Olimpiu , Aluţei Adrian , Mândru Dan
Published: June 2010

In this paper the authors present three wheeled-type in-pipe modular robotic systems, which are characterized by their adaptable structure based on linkage mechanisms. These modular systems are composed of driving modules (which use mechanisms with articulated elements) and passive modules.
Research of Influence of Vibrations on Calibration Quality of Line Scale Gauge
Authors: Kilikevičius Artūras , Vekteris Vladas , Slivinskas Kastytis , Kasparaitis Albinas , Juraitis Sigitas
Published: June 2010

The essence of the considered problem is to improve line scale gauge calibration quality by studying vibrations that are induced during the calibration process. To assess the influence of vibrations it is necessary to solve a lot of scientific and technical tasks. Serious difficulties were confronted during the mathematical analysis - development of analytical model and determination of its coefficients. An in-depth analysis of line scale measurement means had to be performed to this aim, because only experimental measurements enabled to estimate the majority of coefficients.
Dynamics of Dust Explosion Localizing System
Authors: Rinkeviciene Roma , Poška Algimantas Juozas , Slepikas Alvydas
Published: June 2010

The problem of dust explosion in corn processing enterprises is analyzed. System for localizing of dust explosions with dampers driven by linear induction motors (LIM) is considered. The paper presents the developed mathematical and computer models of a damper drive together with results of simulations.
Mechanical and Physicochemical Properties of Some Originally Made Composite Materials for Dental Fillings
Authors: Mystkowska Joanna , Rokicki Gabriel , Sidun Jarosław , Dąbrowski Jan Ryszard
Published: June 2010

This work presents results of research on compressive strength, microhardness, polymerization shrinkage and water sorption of some specially developed composite materials for dental fillings. The investigated powder fillers were divided into two groups: fluorine-based fillers, such as fluoridated glass, strontium fluoride, ytterbium fluoride and additives of improved mechanical characteristics such as nanosilica and polyethylene. The influence of fluoride ion source on the properties of the composite materials was evaluated. Tests were performed just after the material polymerization and, additionally, after seven, thirty and sixty days. Some small differences between composites were observed.
Cobalt Base Clad Layer Resistance on the Corrosion under Low Sulfur Pressure
Authors: Smolenska Hanna
Published: June 2010

The paper considers the sulphidation of the clad layers made of the cobalt base powder and prepared by the multi-overlapped tracks and sublayers fabricated using laser cladding process applied at 800°C under sulphur partial pressure ps2= 10e-8 atm and ps2= 10e-10 atm for 24 hours. The phase compositions of the scale were different. In both cases changes in the layer under the scale exhibited similar tendency – decomposition of the carbides from the interdendritic regions and severe internal corrosion along the dendrite boundaries.
The Influence of Strain Rate and Strain Intensity on Retained Austenite Content in Structure of Steel with TRIP Effect
Authors: Wiewiórowska Sylwia
Published: June 2010

TRIP (transformation induced plasticity) steels are low and medium-carbon steels containing soft ferritic groundmass responsible for low yield point and phases of hard particles such as martensite and/or bainite, which ensure high values of tensile strength. The most important content in structure of TRIP steel is occupied by a non-transformation retained austenite. The advantageous properties of these steels are obtained as a result of martensite transformation generated by plastic deformation process. The retained austenite induces increase of steel plasticity till the moment when by the impact of plastic deformation will undergo deformation in martensite, which results in the increase of steel mechanical properties. The speed of transformation of retained austenite in martensite is highly dependent on strain magnitude and strain rate magnitude. The paper presents the research of strain rate and intensity on retained austenite content ensuring TRIP effect in structure of low carbon steel (0.29%C). Finite element analysis for different strain rate and strain degree values in upsetting test was performed by means of software FORGE 3D. The practical analysis obtained from simulation results was realized by using metallurgical processes simulator Gleeble 3800.
The Operator Protective Structures Testing for Mining Machines
Authors: Derlukiewicz Damian , Karliński Jacek , Iluk Artur
Published: June 2010

The study presents selected problems concerning the testing of protective structures for the mining machines in the field of passive safety. Such machines equipped with protective structures must meet the requirements of the relevant regulations and standards. Requirements of conducting experimental tests of protective structures: FOPS, ROPS and RSPS are specified. The paper provides the principles of development of computational models for numerical simulations by means of finite element method. A detailed example of comparison of experimental and simulation results for a protective structure is presented.
Surface Roughness Model for Components Created by Stereolithography Method
Authors: Dzionk Stefan
Published: June 2010

Rapid prototyping (RP) can fabricate complex 3D physical models without geometric limitations. The surface of the RP processed components is excessively rough (called stair-step effect) and depends on several parameters such as thickness of layer, position on the platform, etc. This paper presents several surface roughness models and results of experimental research.