bluuebunny/crossref_metadata_2025 huggingface dataset:
The Fabrication of Titanium Aluminide Matrix Composite Sheet by Rolling and Reaction Annealing
Authors: Geng Lin , Wang H.L. , Song Y.B. , Zhang Jie
Published: June 2010

In this work, Ti5Si3 and TiC particle reinforced titanium aluminide matrix composite sheet was fabricated by rolling and reaction annealing using the starting materials of SiCp/Al composite and pure titanium sheet. The deformation compatibility of both starting materials and microstructure evolution during reaction synthesis were studied. The results show that titanium has the similar deformability with SiCp/Al composite via the introduction of SiC particles and the selection of proper rolling temperature. Titanium aluminide matrix composite reinforced by Ti5Si3 and TiC was synthesized by reactions during the annealing. The reactions include the formation of titanium aluminide matrix by the diffusion synthesis between titanium and aluminum, as well as reinforcements (Ti5Si3 and TiC) by in-situ reaction between SiC and titanium.
Welding Soundness of a Thick-Walled 9Cr-1Mo Steel
Authors: Ryu Woo Seog , Kim Sung Ho , Kim Dae Whan
Published: June 2010

High Cr ferritic/martensitic steels are demanded to join using favorable welding processes with economical and metallurgical advantages in order to apply to the thick-walled reactor pressure vessel of a very high temperature gas cooled reactor. Narrow gap welding technology was adopted to weld a thick-walled 9Cr-1Mo-1W steel with thickness of 110mm. The welding integrity was checked by non-destructive examination, optical microscopy and hardness test, and the homogeneity through welding depth was checked by absorbed impact energy and tensile strength. The optimizing welding conditions resulted that a narrow U-grooved gap with almost parallel edges was sound in actual practice, and the coarse grain zone was minimized in the heat affected zone. The absorbed energy of 75±25 J through welding depth was acceptable in scatter band to check the uniformity through the welding depth. The ultimate tensile stress and yield stress were about the same through welding depth at 650±10 MPa and 500±10 MPa, indicating no difference through welding depth. Elongation was also almost same through depth, and the fracture surface was appeared as a normal. The weld metal had similar mechanical properties to base metal. The upper self energy of weld metal was 194J, and the ductile-brittle transition temperature was 30°C. The tensile behavior was the typical trend with temperature, and YS and UTS of weldment were slightly higher than base metal by nearly below 10%. Thus, it concluded that the soundness of the narrow gap welding of a thick-walled 9Cr-1Mo-1W steel was confirmed in terms of the welding uniformity through the depth and mechanical properties.
Advanced Steel Design by Multi-Scale Modeling
Authors: De Cooman Bruno C. , Bhadeshia H.K.D.H. , Barlat Frédéric
Published: June 2010

The present contribution highlights the approach to multi-scale steel design used at the Graduate Institute of Ferrous Technology (GIFT). Multi-scale modeling combining ab-initio methods, molecular dynamics, crystal plasticity modeling etc. enables GIFT researchers to gain a better fundamental understanding of phase and lattice stability, magnetic properties and basic mechanical constants. In addition, these methods allow for the reliable determination of critical material parameters. The opportunities for the development of new steel grade is thereby greatly enhanced and, when these new materials-oriented methods are combined with the more traditional engineering modeling methods, the challenges related to the large scale production of new steel grades can also be addressed.
The Stability of γ ’-Co3(Al,W) Phase in Co-Al-W Ternary System
Authors: Tsukamoto Yuki , Kobayashi Satoru , Takasugi Takayuki
Published: June 2010

The thermodynamic stability ’- Co3(Al,W) phase (L12) in the Co-Al-W ternary system at 900 °C was investigated through microstructure and EPMA analysis on a heat-treated bulk alloy. To promote microstructural evolution, the bulk alloy was cold rolled before heat treatment. By heating at 900 °C, the ’ phase was formed discontinuously in contact with the -Co (A1) phase. With increasing heat treatment time, however, the fraction of ’ phase decreased while that of , CoAl (B2) and Co3W (D019) phases increased. These results are consistent with our previous work with a diffusion-couple method, indicating that the ’ phase is metastable, and the three phases of, CoAl and Co3W are thermodynamically stable at 900 °C.
Microstructure and High Temperature Strength in Fe3Al Base Alloys Containing Fine Carbide Particles
Authors: Kobayashi Satoru , Makihara Ryo , Takasugi Takayuki
Published: June 2010

The precipitation of carbide particles and high temperature strength in a Fe3Al base alloy with C, Cr and Mo were investigated. The -Fe3AlC (E21) and M2C (B81) phases precipitated in the temperature range between 1000 °C and 600 °C in periods up to 10 h. The -Fe3AlC phase tended to precipitate in a film-like morphology on grain boundaries by annealing at relatively high temperatures. The M2C phase was dispersed in a fine needle shape within grains by annealing at 700 °C. The film-like  precipitates covering grain boundaries as well as finely dispersed M2C particles was suggested to contribute to strengthening at 600 °C.
Phase-Field Simulation on Phase Transformation during Creep Deformation in Type 304 Steel
Authors: Tsukada Yuhki , Shiraki Atsuhiro , Murata Yoshinori , Takaya Shigeru , Koyama Toshiyuki , Morinaga Masahiko
Published: June 2010

Phase-field simulation of phase transformation during creep in Type 304 austenitic steel is performed and simultaneous nucleation and growth of both M23C6 carbide and ferromagnetic α phases are reproduced. Nucleation events of these product phases are explicitly introduced through a probabilistic Poisson seeding process based on the classical nucleation theory. Creep dislocation energy near the carbide is integrated into the nucleation driving force for the α phase. We examine the effect of the dislocation density on precipitation of the α phase, and it is found that a small difference in the dislocation density leads to a significant change in precipitation behavior of the α phase.
Creep Behaviour and Microstructural Changes of Advanced Creep Resistant Steels after Long-Term Isothermal Ageing
Authors: Sklenička Václav , Kuchařová Květa , Svoboda Milan , Kroupa A. , Čmakal J.
Published: June 2010

In this paper we will try to further clarify the creep-strength degradation of selected advanced creep resistant steels. In order to accelerate some microstructural changes and thus to simulate degradation processes in long-term service, isothermal ageing at 650°C for 10000 h was applied to P91, P92 and P23 steels in their as-received states. The accelerated tensile creep tests were performed at temperature 600°C in argon atmosphere on all steels in the as-received state and after long-term isothermal ageing, in an effort to obtain a more complete description of the role of microstructural stability in high temperature creep of these steels. Creep tests were followed by microstructural investigations by means of both transmission and scanning electron microscopy and by the thermodynamic calculations. It is suggested that microstructural instability is the main detrimental process in the long-term degradation of the creep rupture strength of these steels.
Thixomolded® and Thermomechanically Processed Fine-Grained Magnesium Alloys
Authors: Decker Raymond F. , Huang Jack , Kulkarni S. , Jones J. Wayne
Published: June 2010

Thixomolding of Mg alloys produces fine microstructure of about 5-10 micron alpha phase grain size, surrounded by divorced eutectic phases. During the period from 1995 to 2009, this process and microstructure has captured broad applications around the globe - in markets such as electronics (lap-tops, cameras and cell phones), autos, sports and hand tools. Thermomechanical processing has been applied recently to the Thixomolded precursor to further refine the grain size and eutectic phases - providing yield strength above 300 MPa, fatigue strength of 150 MPa along with elongation of 10%. Alloys studied include AM60, AZ61L and thixoblended alloys of higher Zn content. Microstructure is related to processing and properties. Metal/epoxy fiber composites based on this Mg product have demonstrated yield strength of 900 MPa, with E of 90 GPa.
Research on High Strength and High Toughness Titanium Alloy with Damage Tolerance
Authors: Zhao Yong Qing , Qu Heng Lei
Published: June 2010

As the concept of aerospace design is changed, research objectives of titanium alloys also changed from high strength to high damage tolerance. High strength, high toughness titanium alloys with damage-tolerance have been investigated under the support of a national project since 2003. TC21 titanium alloy is the first Chinese-developed high strength, high toughness and damage-tolerance titanium alloy. The mechanical property of TC21 alloy is sensitive to solution temperature and aging temperature. The rods of TC21 alloy with the diameter of 20mm and 90mm possess good mechanical properties after solution at 900°C followed by aging at 600°C.
Effect of Bi Addition on Thermal Stability and Tensile Ductility of Mg-3%Zn-0.4%Zr Alloy
Authors: Jun Joong Hwan , Lee Min Ha
Published: June 2010

Thermal stability of  grains and tensile ductilities at room and elevated temperatures were investigated and compared for Mg-3%Zn-0.4%Zr and Mg-3%Zn-0.4%Zr-1%Bi alloys in hot-rolled state. The Bi-added alloy showed slightly finer-grained microstructure with enhanced thermal stability, which is closely associated with fine Mg-Bi compounds acting as obstacles for the migration of grain boundaries. The Mg-3%Zn-0.4%Zr-1%Bi alloy exhibited better tensile strength at room temperature and tensile ductilities at elevated temperature. Finer and more homogeneous grain structure with higher thermal stability would be responsible for the enhanced tensile properties in the Bi-added alloy.
Effect of Quenching on Aging Behavior of Binary Mg-Zn Alloys
Authors: Nakanishi Ryosuke , Kawabata Tokimasa , Matsuda Kenji , Ikeno Susumu
Published: June 2010

The effects of the Zn content on the aging behavior of Mg–Zn alloys was examined by means of Vickers microhardness measurements and high-resolution transmission electron microscopy (HRTEM). The hardness of Mg–Zn alloys with high Zn concentrations increased markedly on aging at 473 K. A higher maximum hardness was obtained at an earlier aging time for alloys with high Zn concentrations. The aging response of Mg–4.7mass%Zn alloy aged at 473 K and quenched in chilled water differed from that of a specimen both aged and quenched at 473 K up to the maximum hardness. HRTEM images of the monolayers on the { }Mg planes were recorded for specimens quenched in chilled water; ' and ' phases were found to exist in the maximally aged specimen. Compared with the specimen quenched in water, the number of ' phases was lower in the specimen that was both aged and quenching at 473 K. It was suggested that the difference in the aging response is related to the formation of monolayers in the early stage of aging.
Warm Hydroforming Process with Non-Uniform Heating for AZ31 Magnesium Alloy Tube
Authors: Manabe Kenichi , Morishima Toshiji , Ogawa Yu , Tada Kazuo , Murai Tsutomu , Nakagawa Humiyuki
Published: June 2010

In this study, non-uniform heating approach in warm T-joint forming process is attempted for the AZ31 magnesium alloy tube. For this purpose, finite element simulation is performed to analyze the appropriate temperature distribution. The validity of the finite element(FE) model of T-joint tube hydroforming(THF) is verified by comparing the FE simulation and experimental results. Using this FE model, appropriate temperature distribution was suggested. In addition, it was showed that the wall thickness could be more uniform by optimizing the temperature condition.
Effect of Temperature on Plastic Buckling Strength of Shot Peened Pipe of Magnesium Alloys
Authors: Fukuda Izumi , Harada Yasunori , Tanaka Yuichi
Published: June 2010

This paper deals with the effect of temperature on plastic buckling strength of cylindrical pipe of some magnesium alloys subjected to shot peening process. Workpieces are three cylindrical pipes of AZ31, AZ61 and AZ80 magnesium alloys. The shape of pipe is 30mm in height, 16mm and 14mm in outer and inner diameters. The shot peening treatment was given on the surface of cylindrical pipe using an air-type peening machine. Plastic buckling strength test was performed under axial compression in a case of both ends with fixed condition, at several temperatures between 293K and 573K and at a crosshead speed of 1 mm/min using an Instron-type testing machine. From the experimental result, buckling stresses for all kinds of AZ31, AZ61 and AZ80 alloy pipe were strengthened after the shot peening treatment, but a few of differences for the increasing ratio. The buckling stress of the shot-peened pipe was kept higher than that of as received one up to the test temperature of 473K, however it tended to be around equal at 573K.
Mechanical Properties and Microstructure of AZ Magnesium Alloys Anodized by Phosphate Electrolyte
Authors: Kanadani Teruto , Hikino Shuji , Saijo Atsushi , Hino Makoto , Murakami Koji , Sakakibara Akira
Published: June 2010

Magnesium alloys possess many advantageous functional properties. Use of magnesium alloys, mainly for vehicle parts as well as electronic appliances, has been booming in recent years because of their lightweight compared to aluminum alloys and good creep resistance relative to plastics. Most the use of magnesium for structural applications has been die-cast components and most of this in one alloy, AZ91D. Since magnesium has the lowest electrochemical potential out of all the common commercial metals and is extremely prone to corrosion, it is necessary that it undergoes surface treatment. It is well known that fatigue cracks start near the free surface. Surface microstructure, therefore, should have a significant effect on the fatigue strength. This study was carried out using a mainly phosphate solution without heavy metal onto various AZ magnesium alloys. The effect of anodizing on mechanical properties and microstructure was examined by repeated tension fatigue tests, tensile tests, hardness tests and electron microscopy.
The Effect of Cd Addition on NDE of As-Cast Mg-Cd Alloy in 0.1M NaCl Solution
Authors: Dong Junhua , Xu Shan Na , Ke Wei , Chen Nan
Published: June 2010

The effect of Cd additions on NDE of an as-cast Mg-Cd alloy in 0.1M NaCl solution was investigated using the gas collection method, potentiostatic current decay test and in-situ Laser Raman Spectroscopy. The experimental results showed that, in the cathodic region the addition of Cd reduced the hydrogen evolution and the magnesium hydride formation; in the anodic region the addition of Cd restrained the NDE but slightly increased the anodic dissolution.
Application of Quenching-Partitioning-Tempering Process in Hot Rolled Plate Fabrication
Authors: Zhou Shu , Wang Ying , Chen Nai Lu , Rong Yong Hua , Gu Jian Feng
Published: June 2010

The quenching-partitioning-tempering (Q-P-T) process, based on the quenching and partitioning (Q&P) treatment, has been proposed for producing high strength steels containing significant fraction of film-like retained austenite and controlled amount of fine martensite laths. In this study, a set of Q-P-T processes for C-Mn-Si-Ni-Nb hot rolled plates are designed and realized. The steels with Q-P-T processes present a combination of high strength and relatively good ductility. The origin of such mechanical properties is revealed by microstructure characterization.
Study of Thermal Behavior in a Kroll Reactor for the Optimization of Ti Sponge Production
Authors: Bae Hyun Na , Kim Seon Hyo , Lee Go Gi , Jo Sung Koo , Jung Jae Young
Published: June 2010

The titanium reduction from titanium tetrachloride (TiCl4) by molten magnesium pool, called the Kroll process, is regarded as a well-known process for the commercial-scale production of titanium sponge. Purified titanium tetrachloride vapor reduced by magnesium, forms sponge titanium with generating excessive heal. The heal transfer phenomena in a Kroll reactor should be thoroughly understood for productivity and quality enhancement. In this work, a computational modeling method to describe the thermal behavior in the TiCl4 reduction reactor was investigated and validated with the measured temperature distribution in a 500kg titanium sponge-capacity pilot-scale reactor in terms of various reduction ratios. The approach model for heat flow phenomenon in a reduction reactor could be utilized as a tool to predict the influence of operating process parameters on the optimization of Kroll process.
Screw Form Rolling of Beta Type Titanium Alloy Preliminary Worked by Torsion
Authors: Kume Kazuhiro , Furui Mitsuaki , Ikeno Susumu , Ishisaka Yusuke , Yamamoto Masayuki
Published: June 2010

Beta type titanium alloys in a cold processability are light, have high strength, excellent corrosion resistance and the same level as Young's modulus of human bone. Therefore, beta type titanium alloys are used for plant facilities such as nuclear plants, architectural materials, aircraft, car, biomaterial, medical equipment, glasses and golf club head, etc. Microstructure and mechanical properties of beta type titanium alloys processed by rolling and heat treatment have been reported [1]. Additionally, screw form rolling using beta type titanium alloys has also been reported [2]. However, the development in those characteristics after the preliminary working by torsion has been unknown.
Effect of Pre-Ageing on the Artificial Ageing Response of Al-Mg-Si(-Cu) Alloys
Authors: Cao Ling Fei , Rometsch Paul A. , Zhong Hao , Muddle Barry C.
Published: June 2010

The effect of different pre-ageing treatments on the subsequent artificial ageing response of Al-Mg-Si(-Cu) alloys have been investigated using hardness, tensile and electrical conductivity testing. The microstructural evolution was characterised by differential scanning calorimetry (DSC) and 3-dimensional atom probe (3DAP) analysis. Pre-ageing treatments were carried out at 160-250°C for short times. Results show that the early stage artificial ageing response after 30 minutes at 170°C is strongly influenced by the pre-ageing and natural ageing conditions. A pre-ageing treatment performed for a short time at a high temperature and within a short delay after solution treatment and quenching was found to give a promising hardening response during subsequent artificial ageing. The mechanisms by which pre-ageing can reduce the detrimental effect of natural ageing on the artificial ageing response will be discussed in relation to the formation and distribution of clusters, GP zones and/or precipitates.
Effect of Applied Stress on Nucleation and Growth of Precipitates in a Cu-Be-Co Alloy
Authors: Monzen Ryoichi , Terazawa Tadashi , Watanabe Chihiro
Published: June 2010

The influence of an external stress on the nucleation and growth of disk-shaped G.P. zones has been investigated for a Cu-1.2wt%Be-0.1wt%Co alloy aged at 220 °C. A compressive stress applied in the [001] direction during aging preferentially accelerates the nucleation and growth of the G.P. zones perpendicular to the [001] axis, whereas a tensile stress does not significantly affect those of G.P. zones. The promotion of the nucleation and growth of the G.P. zones perpendicular to the compressive-stress axis can be well understood through the interaction energy between the applied stress and the misfit strains of G.P. zones. The critical diameter of the disk-shaped G.P. zone nucleus was estimated as about 1.3 nm from evaluation of the interaction energy.
Solute Segregation at Σ11(113)[110] Grain Boundary and Effect of the Segregation on Grain Boundary Cohesion in Aluminum from First Principles
Authors: Uesugi Tokuteru , Higashi Kenji
Published: June 2010

We investigate the energy of segregation of solute Ca at symmetric tilt grain boundary in aluminum from the first-principles calculations. As energy of segregation of Ca is negative, Ca atoms tend to segregate at the grain boundary. Furthermore, on basis of the Rice-Wang model, we study the effect of the segregation of Ca on the grain boundary embrittlement of aluminum. Our first-principles calculations of energies of segregation at grain boundary and free surface show that Ca behaves as embrittler.
Cyclic-Modular Approach for Simulation of Multi-Regime Mechatronic Systems with Hydraulic Components
Authors: Uzunov Oleksandr V.
Published: June 2010

The paper considers a process of development of computer models for mechatronic multi-regime systems. A simplified approach for model development is proposed here. The approach is based on application of library of typical module and element models. The models of the modules are based on cyclic structure. The structure repeats the cyclic process of module operation. The modules of the object are identified by comparing schematic diagram with the typical modules of the library. System model is obtained by assembly from typical models of the elements and modules in accordance with the schematic diagram. The application of the approach is illustrated by providing the example.
Design of a Low-Cost Submicron Measuring Probe
Authors: Hermann Gyula
Published: June 2010

The paper presents a new low-cost probe design. The moving element of the probe head consists of the stylus and a cross-form intermediate body with a small aluminium enhanced mirror at the two ends and at the center. The intermediate body is suspended on four springs made of beryllium-copper foils. The displacement of the probe tip is calculated from the displacement and the rotations of the mirrors measured by commercially available modified optical pick-ups.
A Reusable Agent-Based Framework for Smart Embedded Systems
Authors: Kazanavicius Egidijus , Kazanavicius Vygintas , Ostaseviciute Laura
Published: June 2010

Embedded computing systems still remain one of the underlying priorities in worldwide research communities. This paper presents an agent-based approach for embedded real-time systems design based on a reusable framework. The essence of our work lies on smart environment domain. Jade - a Java-based middleware is selected as a platform, facilitating the development of multi-agent embedded systems framework. Generic system architecture, framework prototype implementation and, subsequently, smart refrigerator control application are demonstrated, reasoning that the proposed method is effective in dealing with challenges raised by issues in contemporary embedded system development.
Sensorless Vibratory Manipulation of the Automatically Assembled Parts
Authors: Bakšys Bronius , Baskutiene Jolanta , Povilionis Algis Benjaminas , Ramanuskytė Kristina
Published: June 2010

Presented paper considers the experimental analysis of vibratory manipulation and interdependent alignment of the parts prior to automated assembly. Different values of vibration parameters and parameters of the dynamic system provide possibility to influence the duration of part alignment process. Mating part manipulation on the plane, excited along two perpendicular directions, was also analyzed and different search trajectories were considered.
Research of Vibrations of a System with in Series Connected Elastic Elements Joining a Mass with a Support
Authors: Marcinkevičius Andrejus Henrikas
Published: June 2010

Theoretical analysis of vibrations of a system in which the mass is connected with the support in series of more than one elastic element had shown that there is possibility to provoke additional resonances. Condition of it is change of damping values of the system near the supposed resonance frequency defined calculations. Feed mechanism of cylindrical grinding machine of older design was researched from that point of view. The mechanism consists of chain of elastic elements in series connecting the wheelhead with the bed of machine. Large friction forces exist in the chains of elements and in the wheelhead ways. Analysis results are presented in the paper.
Control of Two-Dimensional Vibrating System
Authors: Kłosiński Jacek , Majewski Ludwik , Trąbka Arkadiusz
Published: June 2010

A strategy for control of a system of two electrical vibrators mounted onto the vibrating plate of a typical small table vibrator was discussed in the present paper. The aim of the considered control system is rapid positioning of counterbalances for ensuring achievement of the assumed directions of vibrations and loading forces (where , m is unbalanced mass, ω is angular velocity of the vibrator shaft, e is distance between the unbalanced mass and the vibrator rotary axis). The strategy of the control consists in setting of different directions of vibrator rotations together with controlled change of vibration frequency and amplitude. Numerical analysis was performed. The obtained results are presented in a graphical form.
Dynamical Flexibility of Complex Damped Systems Vibrating Transversally in Transportation
Authors: Zolkiewski Sławomir
Published: June 2010

The paper deals with the problem of transversal damped vibrations of complex systems in transportation. Many engineering systems are composed of subsystems and there is a need in technical applications to derive the overall model of such systems. Presented model is based on the particular models derived in previous research works of the author.
High Efficiency Radial Passive Magnetic Bearing
Authors: Falkowski Krzysztof , Henzel Maciej
Published: June 2010

Passive magnetic bearing with Halbach array is presented in this paper. The array uses permanent magnets with radial and axial magnetization to augment the magnetic field on one side of the array and cancel it on the other side. The design of the bearing consists of ring-shaped magnets of 60x70 mm and 75x85 mm with different orientation of magnetization. The designed passive magnetic bearing has air gap of 2.5 mm, stiffness 129297 N/m and maximal value of load 200 N. The bearing ensures magnetic levitation and stabilization of rotor in a work point. The paper presents the design of the passive magnetic bearing as well as the experimental setup together with investigation results.
Limb/Ground Impacts and Unexpected Impacts Control Strategy for a Model of a Walking Robot Limb
Authors: Lipiński Krzysztof
Published: June 2010

The paper deals with numerical analysis of dynamics of walking robots. The focus is on limb/ground contact. Normal and tangent direction are considered separately. In the normal one, the contacts are modeled as unilateral constraints. In the tangent one, slip and friction are considered. As the contacts are unilateral, nonzero velocities could be present before the contact. These velocities diminish rapidly, and significant contact forces are present. The forces have destructive influence on the robot structure, and the impulsive changes of the arms velocities can disorient the control system. In the paper, the impact consequences are discussed, as well as consequences of installation of a 0/1 contact sensor. A 3D mechatronic multibody model of a quote of a robot is considered. Its limb is driven by DC motors and controlled by a dedicated control system. With the zero signals from the sensor, the control prevents a constant velocity of the limb end. The normal component of the velocity has to be stopped at the positive signals, and the motor current has to be reduced. Exemplary calculations are presented in the paper.
Universal Navigation Algorithm Planning Platform for Unmanned Systems
Authors: Sell Raivo , Leomar Priit
Published: June 2010

The paper deals with route planning and message exchange platform development for unmanned vehicle systems like Unmanned Ground Vehicle (UGV) and Unmanned Aerial Vehicle (UAV). Existing solutions for both types of vehicles are discussed and analyzed. Based on existing solution an unified concept is introduced. In this paper we present the study where the universal navigation algorithm planning platform is developed aiming to provide common platform for different unmanned mobile robotic systems. The platform is independent from the application and the target software. The navigation and action planning activity is brought to the abstract layer and specific interfaces are used to produce the target oriented code, describing two different test platforms are presented and co-operation scenarios.
Energy-Saving Mechatronic System for Fatigue Tests of Materials under Variable-Amplitude Proportional Bending and Torsion
Authors: Macek Wojciech , Macha Ewald
Published: June 2010

The paper presents structure and principles of operation of the fatigue test stand for specimens subjected to polyharmonic proportional bending and torsion. The stand is equipped with a digital control system based on data acquisition board Daqboard/2000 and LabVIEW environment. The history of polyharmonic loading is a sum of four harmonic components of various amplitudes, frequencies and phases adjusted by means of four rotating disks with unbalanced masses of the inertial vibrator. Application of a computer with the software elaborated by the authors and the control system enables determination of fatigue characteristics of the material under constant or variable amplitude bending, torsion and any combination of bending with torsion.
Development of Finite Element Model of Reorientation of Cementite Lamellae in Pearlite Colonies in Wire Drawing Process for Wires Made from High Carbon Steel
Authors: Muskalski Zbigniew , Milenin Andriy
Published: June 2010

Studies of properties of pearlitic steel wires used for production of metal cord or mining hoisting ropes have revealed a relationship between the orientation of cementite lamellas in the material and the mechanical properties of the wire and its resistance to cyclic loads. Influence of technological parameters on the orientation of cementite lamellas in wire was established. Experimental determination of the range of inclination angles of cementite lamellas in a given pearlite colony, at which their advantageous orientation, parallel to the wire axis, occurs, is not feasible in practice. Therefore, the only approach for solving this problem was to develop an appropriate mathematical model. Solution of the formulated problem proceeded in two stages. At first, the DRAWING2d program [3], modified and adapted to the needs of the task, was employed. The software incorporates a model based on the theory of plastic flow of the rigid-plastic medium. The boundary problem of the theory of plasticity is solved in this model considering the flow of heat and material heating due to plastic deformation and friction. Transfer of all strain tensor components data from draw to draw enabled simulation and optimization of the multi-stage drawing processes. Based on the model, strains fields and flow velocities were determined for the whole cross-section of the material being deformed in a particular draw. At the second stage, a program was developed to model the deformation of a single pearlite colony of dimensions corresponding to those of grains occurring in the actual structure of pearlitic steel after patenting. The mechanisms of deformation of the pearlite colony, the boundary conditions related to interaction of adjacent grains, and the rheology of cementite and ferrite were also accounted for.
Surface Activity and Fluid Sorption of Titanium Alloys Soaked in SBF Solution
Authors: Mystkowska Joanna , Deptuła Piotr , Bakier Sławomir , Sidun Jarosław
Published: June 2010

In the paper a study of surface composition and fluid sorption by several titanium alloys immersed in a simulated body fluid is presented. Four materials were investigated: pure titanium, two beta titanium alloys and stainless steel 316L. All the materials were prepared using cold pressing and sintering. Sample plates were submitted to nucleation and growth of calcium phosphates precipitated from SBF solution containing calcium, phosphate and other ions. Analysis with scanning electron microscope has revealed some calcium phosphates aggregates on surfaces of all the alloys. The results indicate that the nucleation and growth of phosphates depend on the alloy composition and the process is more intensive in the case of titanium alloys with niobium additions. On the other hand, this material is characterized by the smallest SBF sorption. Chemical analysis using near infrared spectroscopy indicated a presence of some organic groups on the material surface.
Cavitation Erosion Resistance of Austenitic Microstructure Created by Laser Beam
Authors: Szkodo Marek
Published: June 2010

This work presents investigations of cavitation properties of different austenitic microstructures formed by laser beam machining of X5CrNi18-10 and C45 steels. X5CrNi18-10 steel was alloyed with TiC and Mn powders and surface layer of C45 steel was enriched with Ni, Mn, Cr and Nb. For alloying the cw CO2 laser beam was used as a power source. Cavitation behaviour of produced layers was investigated in a rotating disc facility. The results reveal different susceptibility to plastic deformation and strain hardening degree of surface in the early stage of cavitation erosion.
Magnetic Properties of Co2On (n = 1-9, 12) Nanoparticles
Authors: Tamulienė J. , Vaisnoras Rimas , Badenes Gonsal , Balevicius Mindaugas Leonas
Published: June 2010

In this paper we discuss magnetic properties of ConOm (n = 2,6, m = 0-9,12) nanoparticles. Based on quantum chemistry research results we present and consider reasons due to which magnetic properties of small particles are different.
Determination of Temperature Range Enabling the Plastic Deformation Process of CP302 Solder
Authors: Wiewiórowska Sylwia , Muskalski Zbigniew , Suliga Maciej
Published: June 2010

The development of new technologies of metal joining processes including brazing methods requires improvement of solder properties. Copper-based brazing solders with phosphorus and tin additions belong to the group of silver-free brazing alloys with low ductility. The most common form of these solders are bars and wires so there is a need to determine the causes of technological problems concerned with plastic deformation of the solders. In the literature, except for the chemical composition and temperature of brazing, we can not find the details regarding the change of solder structure during heating processes. The preliminary tests carried out in the industry indicate high plasticity of solder in the narrow range of temperature. This encouraged the authors of the paper to perform dilatometric testing with the aim of establishing the precise temperatures of solder phase changes. The metallographic research with the use of scanning electron microscopy enabled the determination of phase composition of “freezing” structures and the evaluation of their flexibility to the plastic deformation.
Properties and Application of Sintered Stainless Steel as Interconnectors in Fuel Cell
Authors: Włodarczyk Renata , Dudek Agata
Published: June 2010

This study presents opportunities of application of sintered materials for interconnectors in low-temperature fuel cells. The task of these cell components is to provide even distribution of both fuel and oxidant. Materials for interconnectors must possess good thermal conductivity, conduct electricity and have high strength. It is also required that the material is corrosion-resistant under cell operating conditions. Due to multifunctional nature of these elements, selection of materials for interconnectors is extremely difficult. This paper presents analysis of structural properties and effect of pH level in sulphate solutions (pH = 2, 4, 6) on corrosion resistance in austenitic and ferritic sintered materials.
Optimal Design for the Environment of the Means Transportation: A Case Study of Reuse and Recycling Materials
Authors: Chamier-Gliszczyński Norbert
Published: June 2010

In the paper a topic of environmentally-oriented optimal design of means of transport is presented focusing on the example of reuse and recycling of materials. The following was applied in the field of environmental analysis of transport means: LCA (Life Cycle Assessment), LCC, LCI, DfE, DfR, DfD, end-of-life, assembly, disassembly, recycling, reuse, modeling of material separation. Results of the analysis enabled identification of components of transport means that dominate with respect to generated unfavorable environmental interactions. This allowed indicating areas, where modifications can strongly improve environmental image of means of transportation.
The SMA Wires Application in the Braille Monitor
Authors: Kwaśniewski Janusz , Dominik Ireneusz
Published: June 2010

The main aim of the research was to establish whether SMA wires are suitable to build a Braille tactile display. The particular goals were to design, fabricate and programme a device, which would be cheap, convenient and easy to use, and would work independently from the PC. The prototype was to have one letter at least and be ready to add more letters in the future. In the article the conception of the prototype design is presented. The single pin was designed in the shape of a vertical cylinder of 3 mm in diameter. A significant disadvantage of modern Braille monitors is the length of the piezo crystals that prevents engineers from building large matrices. Thanks to SMA wires the possibility to build a large matrix is unlimited. Having built a Braille letter prototype the research on the selection of an appropriate control method was launched. Eventually, it was decided that all of the control tasks would be covered by one single chip – the PIC18F4455 processor. This unit had all the necessary peripherals, such as USB, timers, as well as enough speed to run the software. The designed device has proved that SMA wires can be used for this kind of application [2]. It has also demonstrated that graphic Braille monitors can be built. In the current stage of research, this design is not ready for mass production, but additional research can lead to the improvement of this device.
Structure and Properties of Bioceramics Layers Used for Implant Coatings
Authors: Dudek Agata , Włodarczyk Renata
Published: June 2010

Ceramic materials included in the group of advanced materials are increasingly used in different fields of science and technology as well as in everyday life. Hydroxyapatite ceramics (HAp, HA), based on calcium phosphates, i.e. chemical compounds being a constituent of natural bone, is found to be one of the best implantation materials for bone surgeries and dentistry. Due to poor mechanical properties of hydroxyapatite ceramics, the attempts are made to modify HA materials in order to extend the scope of current applications. It is also necessary to maintain high biocompatibility and bioactivity. Reported investigations encompassed comparison of functional properties of HA and HA+ZrO2 coatings (modified with 8%wt. Y2O3) as well as coatings remelted with laser beam. Microstructural and phase analyses of the coatings before and after remelting were carried out. In order to determine biocompatibility of the coatings after plasma spraying and remelting, corrosion resistance testing was also performed in Ringer’s solution.
Application of Syntactic Pattern Recognition Approach in Design and Optimisation of Group Machining Systems
Authors: Siemiatkowski Mieczyslaw
Published: June 2010

The focus of this paper is on planning applications of group technology (GT) and the design of related layouts for multi-assortment cellular manufacturing (CM) of mechanical parts. A methodical approach is developed to optimally solve cell formation (CF) problems with CM systems design, which consists in the identification of machine cells and corresponding part families. The approach involves the use of syntactic pattern recognition concepts from the field of artificial intelligence (AI). It is based on methods of strings matching and clustering, applied extensively in genetics, molecular chemistry and biological sciences. The CF strategy followed implies clustering character strings that denote machine sequences in process routings. Numerical quantification of dissimilarity between part routings by a specific distance measure and the concept of average linkage clustering algorithm (ALCA) are at the core of the clustering procedure. The use of the approach is studied numerically with regard to a real industrial case and diverse layouts of cellular system are considered, including those with machine sharing. Group process alternatives with given system layouts and workflows prototyped by definite job sequencing rules, are simulated using programmed models. Generated design solutions are subjected to further analysis and quantitative evaluation by assumed measures of their operational performance.
Analysis of Asymmetrical Rolling Process of Multilayer Plates
Authors: Skoblik Robert , Rydz Dariusz , Stradomski Grzegorz
Published: June 2010

. Literature provides three basic methods of explosive cladding, developed by Darenport and Person. Welding trials were performed in two- and three-layer arrangements, where in the second case, copper plates were welded with plates made from aluminium alloys with an interlayer of pure aluminium. Explosive welding technology does not always allow for joining of sheets of specific thicknesses. In order to obtain such thickness, they need to be rolled.
The paper presents results of numerical study of asymmetrical rolling process of multilayer plates M1E-Al99.8-AlMg5. Numerical modeling of rolling of multilayer plates was realized by means of Forge 2D program that is based on finite element method. Obtained research results enabled to elucidate the process of rolling of multilayer plates.
Identification of Internal Stresses in Bolted Flanged Joints
Authors: Smolnicki Tadeusz , Karliński Jacek , Derlukiewicz Damian
Published: June 2010

In bolted flange joints of flexible constructional elements, bolts are subjected not only to tension and torsion but also to bending loads. Identification of straining of each bolt is only possible by means of numerical methods e.g. the finite element method. In the case of large objects, the calculation problem is faithful projection of the phenomena occurring in direct zone of the contact of screw-nut pair. The application of global equivalent models of the whole joint is necessary in order to make it possible to precisely determine internal loads in individual bolts and then local models to establish stress fields necessary to assign durability. Calculation methodology based on the construction of two coherent models has been described: global - for the entire flange joint, and local - for a single bolt joint. The elaborated methodology was applied to evaluate a flange joint in a heat exchanger with rotating heating surfaces that was subject to damage. The causes of damage of the flange joint were determined.
Intelligent Agent Find its Way in the Drawing
Authors: Sokas Algirdas
Published: June 2010

This article analyzes intelligent agent in the changing drawing. The objective is to find the shortest way between two points in the flat space with prominent polygon fences. This is an idealized task that a robot (agent) has to solve seeking to find its way in the environment (drawing). The creation tasks of intelligent agent are solved with agent unified modeling language. Graphical system can analyze drawing, forming graph, calculate graph matrices, extract route and prepare programs form with information. It discerns objects-classes: agent, graph, route, which have some properties and methods. System test is executed with three drawings. Design system and example of intelligent agent in the drawing is presented. Intelligent agent systems are discussed and conclusions are made.
Tensor Interpolation of Tribological Wear in Ionitriding of 316L Steel
Authors: Frączek Tadeusz , Olejnik Michał , Knapiński Marcin , Biernat Grzegorz
Published: June 2010

The research results for polynomial tensor interpolation of tribological wear of austenitic 316L steel are analyzed for the first time in this paper. A tribological study was carried out on the tester T-05, both for samples after the process of glow discharge nitriding and for samples of 316L steel in the initial state [1, 2]. The influence of the nitriding parameters on the weight loss of the samples during the abrasion test and the friction coefficient of the abrasion pair were determined. In this paper the actual results which were obtained so far during the research of tribological wear in an interpolative area were put together with the theoretically determined and experimentally verified real research results for tribological wear in the area beyond the scope of interpolation. It was determined that each of the selected nitriding parameters significantly affects abrasive wear resistance of 316L steel, at the same time, in the nitriding process, as time and temperature increase the resistance to wear abrasion becomes better. The mathematical model for planning of experiments with different glow discharge nitriding processes combined with polynomial interpolation of the obtained research results of many variable functions will enable to choose the nitriding process parameters to obtain the assumed and required property of useful nitrified elements. The developed computer program enables multidimensional interpolation of the research results and is a universal tool which can be used in any research field.
Microstructure State and Heat Treatment Influence on Barkhausen Noise Parameters and Residual Stress Measurements
Authors: Garstka Tomasz
Published: June 2010

In many cases of residual stress testing by Barkhausen method, the microstructure of the sample used for calibration procedure and tested material is fairly different though made form the same steel grade. These differences can be observed even in the same investigated product, for example, in steel shapes. Due to this fact, this paper presents the preliminary results of experimental investigations of the influence of microstructure state (modified by heat treatment) on Barkhausen noise parameters and, finally, on residual stress measurement by Barkhausen method.
Investigation of Copper Fragmentation Property
Authors: Janiszewski Jacek , Panowicz Robert
Published: June 2010

The paper presents experimental and numerical results of the investigation of fragmentation process of copper rings expanded with maximum radial velocity close to 170 m/s. The experiments were performed on Cu-ETP rings of average diameter of 32 mm and cross-section of 1 x 1 mm. The authors particularly focus on the statistical concept of the ring fragmentation process. In connection with the above, the number of fragments, their size and distribution were determined on the basis of multiple experimental ring tests. It was established that for selected loading condition, the copper ring fracture appeared when the strain reached the average values of 0.35 and the average number and length of fragments were about 11 and 13 mm, respectively. Moreover, the numerical prediction of the fragment size distribution was carried out using the Mott fragmentation model.
Effect of Erosive Particle Velocity on the Intensity of Polymeric Coating Wear
Authors: Kotnarowska Danuta
Published: June 2010

The paper deals with experimental investigation of erosive wear of acrylic coating. The research was carried out on the erosive wear under the influence of alundum particles (grain size of 0.6 – 0.7 mm) striking the coatings at the angle of 45 degrees. It was established that intensity of the erosive wear (under the influence of free falling alundum particles) essentially depends on velocity of erosive particle at the moment of its impact against coating surface. For example, for the lowest velocity value (3.6 m/s) at the moment of impact, erosive wear intensity was equal to 0.4 mm/kg, while for the largest velocity value (5.3 m/s), the intensity doubled in magnitude. The characteristic of erosive wear intensity, depending on erosive particle velocity, was generated by using second-degree polynomial.