bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Research of High Performance Concrete with Multi-Elements Mineral Admixtures
Authors: Li Ke Liang , Tang Xiu Sheng , Huang Guo Hong , Xu Hui
Published: March 2009

Performing the superposition effect of multi-elements mineral admixtures, high performance concrete (HPC) with 3% of silicon fume, 20% of fly ash and 40% of ground granulated blast-furnace slag (GGBS) was prepared, and its physical and mechanical properties and durability were studied systematically. The compressive strength and tensile strength of HPC are better than those of ordinary concrete. HPC has high compactness with smaller gas diffusion coefficient and relative permeability coefficient. Adding volume stabilizer and controlling the contents of SO3 in the GGBS and volume stabilizer at 3%, can reduce dry shrinkages effectively. Large mount of mineral admixture was used to make the concentrations of K+ and Na+ in the pore solution and the expansion caused by alkali-silica reaction depress greatly. So the alkali-silica reaction gets controlled markedly. The effective diffusion coefficient of chloride ion is 1.96×10-12 m2/s, which means HPC has a favorable chloride ion penetration resistance. After 15 times of wet-dry cycle, the rates of the rust area and quality loss of the reinforcing steel bars in HPC are only 4.1% and 0.05% respectively, so HPC has better performance of steel protection. The mortar bar did not expand in corrosive sodium sulfate solution, and it means HPC has better performance of sulfate resistance. The performances of frost resistance and carbonation resistance of HPC are also favorable. It’s proved in tests that the superposition effect of multi-elements mineral admixtures can enhance the physical and mechanical properties and durability of concrete greatly.
Effect of Different Mineral Admixtures on Sulfate Attack to Mortars
Authors: Niu Quan Lin , Feng Nai Qian
Published: March 2009

Corrosion resistance coefficient of mortars incorporating different mineral admixtures were tested according to GB2420, and the expansion ratio of mortar bar immersed in 5% Na2SO4 solution was measured according to ASTM C1012. It is shown that all the mineral admixtures, including ground granulated blast furnace slag (SL) fly ash (FA), natural zeolite (NZ) and metakaolin (MK) were effective in decreasing the 15-week expansion and increasing the corrosion resistance coefficient of the specimens immersed in Na2SO4 solution as well.
Technology of Chloride-Resistant High Performance Concrete
Authors: Chen Wei , Mo Hai Hong , Yang Yi Bo , Liang Song , Chen You Wen , Ba Ling Zhen , Chen Jun Sheng , Guo Wen Ying
Published: March 2009

The chloride-resistant high performance concrete to be used is a basic technology to increase its durability in high chloride-ion environment. On the base of “Application technology guide for anti-seawater concrete of Guangdong province” (consultant version), the raw materials, mix proportion, placement of concrete, and the quality tests etc were discussed in detail.
Assessment of Concrete Permeability by a Nondestructive Method
Authors: Hao Ting Yu , Wu Zhi Gang
Published: March 2009

Concrete permeability has been an important part of durability assessment of existing structures. The preliminary application of in-situ permeation assessment by Autoclam system was reported in this paper. The reliability of this nondestructive method has been preliminary proved.
Lessons Learned from Wenchuan Earthquake: Building Materials
Authors: Zhao Bo Ming , Chen Jing
Published: March 2009

It has always been concerned about seismic motion and building materials near faults, but it still remains as an uncertain problem due to insufficiency of case study and information. The paper presents the main cases of seismic disaster by field investigations of M8.0 Wenchuan earthquake, on the relationship among earthquake faults, ground motion and earthquake disasters near fault zone, i.e. the forms of structural damage are very complex in the fault areas, with main forms of shear failure and damage of tension and compression. The brittle materials such as reinforced concrete and masonry materials are prone to partial brittle fracture, and main forms are composed of up and down shake and surface ruptures. The brittle materials are prone to tension and compression damage. By using qualified materials, following building codes, the constructions in urban areas showed good seismic performance. Survey results showed that the framework and the structure of the steel and wood that use the flexible materials with flexible structures possess good seismic performance.
Advances in Research on Correlation of Workability and Rheology of Fresh Concrete: A Review
Authors: Peng Gai Fei , Guo Zhan Qi , Stroeven Piet , Gao Ri , Huang Guang Hua
Published: March 2009

A literature review was carried out to identify advances in research on workability of fresh concrete via both experimental tests and modeling, especially high performance concrete and self-compacting concrete. It is concluded that, in order to achieve better understanding of fresh concrete, especially self-compacting concrete (SCC) and high-performance concrete (HPC), a clear methodology of research should be established as the first step. It is suggested that there is no unique workability test method suitable for all the range of fluidity of fresh concrete, and a specific method should be identified for a proper range of fluidity. As to the relationship between fluidity of concrete and that of paste, future research can be conducted in two aspects, i.e. one is the influence of the quantity of paste in concrete, and another is the influence of fluidity of paste affected by a couple of factors.
Monitoring of CO2 Laser Cutting of Thick Steel Plates by Means of a NIR Camera Based System
Authors: Fallahi Sichani Ehsan , De Keuster Johan , Kruth Jean Pierre , Duflou Joost R.
Published: March 2009

An optical monitoring system has been developed by the authors aiming at real-time monitoring of laser cutting of thick plates of mild steel. This optical system uses photodiodes and a NIR camera as sensors. The concepts and results of the photodiode-based monitoring system have already been reported [1,2]. This paper is dedicated to the development of the optical set-up for camera-based monitoring of the laser cutting process. Firstly, some general aspects concerning the sensing principles and the conceptual design of the physical layout of the camera set-up are discussed. Based on a detailed optical analysis of the proposed conceptual design, some relevant information with regard to the selection of the camera type was obtained. Aspects related to the acquisition and analysis of the images, are highlighted. The initially developed camera set-up is presented. Firstly the design of the corresponding optical path is discussed in detail, including the results of the performed optical analysis. Next the results of the verification tests, performed on this physical set-up, are presented. Finally some preliminary results are included, proving the superior capability of the NIR camera compared to the photodiode-based solution for monitoring purposes.
Double Indentation of Laser Welded Butt Joints of Stainless Steel Sheets
Authors: Santo Loredana , Squeo Erica Anna , Trovalusci Federica
Published: March 2009

In this study, an easy and innovative technique for laser welded butt joint characterization is proposed. AISI 304 sheets, 1.25 mm in thickness, were welded in the butt configuration by means of a high power diode laser (HPDL). Different combinations of the process parameters were considered. For each combination, during the process different thermal cycles were induced in the material generating heat affected zones, which were subsequently tested by the double indentation test method. This test was performed on the sheets by means of two co-axial flat indenters, 1 mm in diameter, made of tungsten carbide (WC); the upper indenter penetrates at a constant rate (0.1 mm/min) into the material, whereas the lower indenter acts as a support. On each side of the seam, 10 indentations were performed at fixed positions with different distance from the centre of the seam, to obtain a load map correlated to the mechanical properties. By comparing the maps of the different laser welded joints, a clear effect of the laser scan speed and the power was found. Furthermore, a wake field effect is recognizable, in fact the loads are symmetric as regards the seam, and there is a clear trend in the direction of the laser path. These results confirm the effectiveness of this method, which is also suitable for on-line application because a very small indentation is left on the sheet.
Asymmetric Rolling as Means of Texture and Ridging Control and Grain Refinement of Aluminum Alloy and Steel Sheets
Authors: Lee Dong Nyung
Published: March 2009

Asymmetric rolling, in which the circumferential velocities of the upper and lower rolls are different, can give rise to intense plastic shear strains and in turn shear deformation textures through the sheet thickness. The ideal shear deformation texture of fcc metals can be approximated by the <111> // ND and {001}<110> orientations, among which the former improves the deep drawability. The ideal shear deformation texture for bcc metals can be approximated by the Goss {110}<001> and {112}<111> orientations, among which the former improves the magnetic permeability along the <100> directions and is the prime orientation in grain oriented silicon steels. The intense shear strains can result in the grain refinement and hence improve mechanical properties. Steel sheets, especially ferritic stainless steel sheets, and aluminum alloy sheets may exhibit an undesirable surface roughening known as ridging or roping, when elongated along RD and TD, respectively. The ridging or roping is caused by differently oriented colonies, which are resulted from the <100> oriented columnar structure in ingots or billets, especially for ferritic
stainless steels, that is not easily destroyed by the conventional rolling. The breakdown of columnar structure and the grain refinement can be achieved by asymmetric rolling, resulting in a decrease in the ridging problem.
Synthesis and Properties of Silica-Modified Polybenzoxazine
Authors: Agag Tarek , Takeichi Tsutomu
Published: March 2009

A series of polybenzoxazine-silica hybrids was papered by blending benzoxazine
monomer with various ratios of tetraethoxysilane (TEOS) as a precursor for silica. The blends
after hydrolysis and condensation of TEOS were thermally treated gradually up to 240oC to afford
the hybrids. The IR spectra and DSC showed the completion of the ring opening of benzoxazine
monomer and formation of silica by the end of the 240oC cure. The inclusion of silica into
polybenzoxazine matrix has a noticeable effect on the thermal and mechanical properties.
Effects of Alloying Elements on Elastic Modulus of Ti-Nb-Ta-Zr System Alloy for Biomedical Applications
Authors: Sakaguchi Nobuhito , Mitsuo Niinomi , Akahori Toshikazu , Saito Takashi , Furuta Tadahiko
Published: March 2009

Effects of alloying elements on elastic moduli (Youngs moduli) of Ti-Nb-Ta-Zr system
alloys for biomedical applications were investigated. In this case, Ti-30Nb-10Ta-5Zr which is the
simplified chemical compositional alloy of Ti-29Nb-13Ta-4.6Zr for biomedical applications has been
selected as the basic alloy composition. Each alloying element content of Ti-Nb-Ta-Zr quaternary
alloys was varied independently. Nb content was varied from 0 through 40 mass % by eight levels. Ta
content was varied from 0 through 20 mass % by five levels. Zr content was varied from 0 through 10
mass % by five levels. Every alloy was fabricated by powder metallurgy processing, followed by
forging.
Ti-30Nb-10Ta-5Zr with single phase, which is a basic alloy composition, shows the lowest
Youngs modulus. phase precipitation in phase has much greater effect on increasing Youngs
modulus than phase precipitation in Ti-Nb-Ta-Zr quaternary alloys.
Fabrication and Properties of TiB2 Reinforced Cu Composites by Electromagnetic Stirring
Authors: Jung Taek Kyun , Lim Sung Chul , Kwon Hyouk Chon , Kim Mok Soon
Published: March 2009

Cu-Ti and Cu-B alloys were separately cast in vacuum arc melting furnace for alloying. These alloys were added to the copper melt of 1500K in the induction furnace and performed electromagnetic stirring at 1000rpm. The cast ingot(dia : 70mm, length : 100mm) was hot extruded with the extrusion ratio of 13:1 after heating at 1073K for 1 hour. The TiB 2 precipitates were observed in the extruded materials and the mean size of TiB 2 precipitates was found to be about 1.5µm. The volume fraction of TiB 2 varies due to the density difference between the TiB2 and the
copper melt. With the increasing of TiB2 contents from 3 to 8 vol.%, the hardness and the tensile strength increased from 951 to 140Hv and from 248 to 278MPa, respectively, and the electrical conductivity decreased from 82 to 70%IACS. However, the mean size of TiB 2 particle was not increased despite increasing an annealing temperature.
Characterization of Friction Welding for IN713LC and AISI 4140 Steel
Authors: Yeom Jong Taek , Park J.H. , Lee J.W. , Park Nho Kwang
Published: March 2009

Friction welding of dissimilar materials, Ni-base superalloy IN713LC and oil-quench plus tempered AISI 4140 steel, was investigated. Friction welding was carried out with various process variables such as friction pressure and time. The quality of welded joints was tested by applying bending stresses in an appropriate jig. Microstructures of the heat-affected zone (HAZ) were investigated along with micro-hardness tests over the friction weld joints. DEFORM-2D FE code was
used to simulate the effect of welding variables in friction welding process on the distributions of the state variables such as strain, strain rate and temperature. The formation of the metal burr during the friction welding process was successfully simulated, and the temperature distribution in the heat-affected zone indicated a good agreement with the variation of the microstructures in the HAZ.
New Cu-Based Bulk Metallic Glasses with High Strength of 2000 MPa
Authors: Shin Seung Y. , Kim J.H. , Lee D.M. , Lee Jong K. , Kim H.J. , Jeong Ha Guk , Bae Jung Chan
Published: March 2009

New Cu-based bulk amorphous alloys exhibiting a large supercooled liquid region and good mechanical properties were formed in a quaternary Cu-Ni-Zr-Ti systems consisting of only metallic elements. The compositional range for the formation of the amorphous alloys that have high glass forming ability (GFA) (> 3 mm diameter) and large supercooled liquid region (> 50 K) is defined in the pseudo-ternary phase diagram Cu-Ni-(Zr, Ti). A bulk amorphous Cu54Ni6Zr22Ti18 alloy with the diameter of 6 mm can be prepared by copper mold casting. The Cu54Ni6Zr22Ti18 alloy shows glass transition temperature (Tg) of 712 K, crystallization temperature (Tx) of 769 K and supercooled liquid region (ΔTx) of 57 K. The Cu54Ni6Zr22Ti18 alloy exhibits high compressive fracture strength of about 2130 MPa with a plastic strain of about 1.5 %. The new Cu-based bulk amorphous alloy with high GFA and good mechanical properties allows us to expect the extension of application fields as a new engineering material.
Effect of Lattice Anisotropy on Simulations of Grain Boundary Movement in Two-Dimensions
Authors: Kroc Jiří
Published: March 2009

This paper try to elucidate some aspects of the impact of using two different types of computational lattices on the solution of simple models like, for example, grain boundary migration and/or dynamic recrystallization.Not surprisingly, the final solution is obviously affected by anisotropy of used lattices but as we know, they are computational lattices.Ho wever, a material itself has its own anisotropy of its lattice probably different from those lattices used in model.Therefore, the main task in nowadays simulations is to get rid of the influence of computational lattice and to achieve the properties of the lattice of the simulated material.
Softening Mechanisms in Two Duplex Stainless Steels Deformed in Hot Torsion
Authors: Cizek P.
Published: March 2009

The aim of the present work was to undertake a detailed investigation of the softening mechanisms during hot deformation of a 21Cr-10Ni-3Mo (steel A) and a 21Cr-8Ni-3Mo (steel B) austenite/ferrite duplex stainless steels containing about 60% and 30% of austenite, respectively. The steels were subjected to hot deformation in torsion performed at 900 °C and 1200 °C using a strain rate of 0.7 s-1 to several strain levels. Quantitative optical and transmission electron microscopy were used in the investigation. Austenite was observed to soften via dynamic recovery (DRV) and dynamic recrystallisation (DRX) accompanied by DRV for the deformation temperatures of 900 °C and 1200 °C, respectively, for the both steels studied. DRX of austenite largely occurred through strain-induced grain boundary migration, complemented by (multiple) twinning, and developed significantly faster in steel A than in steel B, indicating that considerably larger strains partitioned into austenite in the former steel during deformation at 1200 °C. The above softening mechanism was accompanied by the formation of DRX grains from subgrains along the austenite/ferrite interface and by large-scale subgrain coalescence. At 900°C, stressassisted phase transitions between austenite and ferrite were observed, characterised by dissolution of the primary austenite, formation of Widmanstätten secondary austenite and gradual globularisation of the microstructure with increasing strain. These processes appeared to be significantly more widespread in steel B. The softening mechanism within ferrite for the both steels studied was classified as “continuous DRX”, characterised by a gradual increase in misorientations between neighbouring subgrains with strain, for the both deformation temperatures.
Geometric Dynamic Recrystallization in an AA2219 Alloy Deformed to Large Strains at an Elevated Temperature
Authors: Kaibyshev Rustam , Mazurina I. , Sitdikov Oleg
Published: March 2009

The mechanism of new grain evolution during equal channel angular extrusion (ECAE) up to a total strain of ~12 in an Al-Cu-Mn-Zr alloy at a temperature of 475oC (0.75Tm) was examined. It was shown that the new grains with an average size of about 15 µm result from a specific process of geometric dynamic recrystallization (GRX) which can be considered as a type of continuous dynamic recrystallization (CDRX). This process involves three elementary mechanisms. At moderate strains, extensive elongation of initial grains takes place; old grain boundaries become progressively serrated. Upon further ECAE processing, transverse low-angle boundaries (LAB) with misorientation ranging from 5 to 15o are evolved between grain boundary irregularities subdividing the initial elongated grains on crystallites with essentially equiaxed shape. The misorientation of these transverse subboundaries rapidly increases with increasing strain, resulting in the formation of true recrystallized grains outlined by high-angle boundaries from all sides. In the same time, the average misorientation of deformation-induced boundaries remains essentially unchanged during ECAE. It is caused by the fact that the evolution of LABs with misorientation less than 4o occurs continuously during severe plastic deformation. The mechanism maintaining the stability of the transverse subboundaries that is a prerequisite condition for their further transformation into highangle boundaries (HABs) is discussed.
Effect of Niobium and Titanium on the Dynamic Recrystallization during Hot Deformation of Stabilized Ferritic Stainless Steels
Authors: Oliveira Tarcisio R. , Montheillet Frank
Published: March 2009

The study was carried out to understand the mechanisms occurring during dynamic recrystallization of hot deformed 11% chromium stabilized ferritic stainless steels and to compare the behaviour induced by various types of stabilization. It was observed that continuous dynamic recrystallization (CDRX) operates in all materials starting at the onset of straining. Niobium has a more pronounced influence on hardening than titanium during hot deformation, which is due to solid solution strengthening and also to the reduction or stopping of grain boundary migration by solute drag effect. The D2 component, { 2 1 1 }<111>, was found as the major texture component at the steady state for the torsion tests carried along the negative shear direction. It was likely to be formed by the combination of straining and growth of the grains exhibiting both low stored energy and low rotation rate of the crystallographic axes.
Recrystallization Mechanisms in Wire-Drawn Copper
Authors: Gerber Ph. , Jakani S. , Baudin Thierry , Mathon Marie Helene , Penelle Richard
Published: March 2009

Wire-drawn Electrolytic Tough Pitch copper deformed at moderate strain has been investigated with Electron Back Scattered Diffraction in a Scanning Electronic Microscope in order to evaluate the recrystallization mechanisms at the meso-scale. Experimentally, it has been shown that the static recrystallization takes place first in the highly deformed and misoriented areas, in the intermediate regions of the wire. The grains related to the <100> fiber nucleate and grow first in these regions, but some other orientations (including the <111> oriented grains) - that have a combined nucleation/growth potential - develop in second time. The annealing twinning is active from the beginning of the recrystallization and tends to randomize the final recrystallization texture.
Effects of Nuclei Clustering on Recrystallization Kinetics
Authors: Vandermeer R.A. , Juul Jensen Dorte
Published: March 2009

In this work, it is shown that the contiquity ratio, Crr, defined as the fraction of the total grain boundary area of recrystallized grains shared by other recrystallized grains, is a useful experimental parameter for describing the clustering of recrystallization nuclei in partially recrystallized microstructures. Two experimental examples are presented where anisotropic impingement behavior, i.e. non random recrystallized grain distributions, is thought to be important. In the experimental examples, the deviation of Crr from Crr = Vv which is a characteristic of a random
distribution, is clearly shown. The results justify the need for these cases to be modelled, as had been done, by impingement patterns other than the simple random nucleation behavior so often postulated without proof in recrystallization kinetics studies.
Growth Rate Distributions during Recrystallization of Copper
Authors: Vandermeer R.A. , Lauridsen Erik M. , Juul Jensen Dorte
Published: March 2009

New 3D X-ray diffraction microscopy (3DXRD) experiments on recrystallizing bulk grains that nucleated and grew in a 92% cold deformed pure copper during in situ annealing at both 150° C and 160° C are described. Nucleation times, growth velocities and apparent activation energies were determined for each grain. A wide range of apparent activation energies was observed but the average of 123 kJ/mol agreed well with earlier recrystallization experiments on a similar purity copper. It was clear that each recrystallized grain had its own individual characteristics; the grains do not all behave alike as various models would suppose.
Grain Growth after Intercritical Rolling
Authors: Petrov Roumen H. , Kestens Leo , Verbeken Kim , Houbaert Yvan
Published: March 2009

The distribution of the characteristic texture components between the ferrite grains of different size classes has been studied in a steel with 0.082%C, 1.54% Mn, 0.35% Si, 0.055%Nb and 0.078%V after different rolling schedules with a final rolling temperature above or below Ar3. Microstructures and textures were characterized by means of optical microscopy and orientation microscopy. A strong grain refining effect together with a bimodal grain size distribution was observed in the steel both after final rolling in the intercritical region or in the austenite region, close to the Ar3 d temperature. The differences in grain size were interpreted on the basis of three potentially acting mechanisms: (i) transformation- induced recrystallization, (ii) increased mobility of specific grain boundaries and (iii) fast nucleation of ferrite grains on specific sites of the parent austenite microstructure. The experimental data clearly favoured the third of these assumptions as the responsible mechanism for the observed bimodal grain size distributions.
Rolling and Recrystallization Texture of Cold Rolled IF Steel: A Study from Low to High Deformation
Authors: Quadir M.Z. , Tse Y.Y. , Lam K.T. , Duggan B.J.
Published: March 2009

IF steel was homogeneously cold rolled between 30-95% reduction in thickness. The global cold rolling textures showed a gradual strengthening of both stable α and γ components with increasing reduction until ~80% after which γ remained effectively unchanged but α components intensified until 95% reduction of thickness. Deformation Banded (DB) and also fragmented microstructures were found exclusively in γ grains up until about 85% reduction after which DB was unexpectedly detected in α grains, becoming significant after 95% reduction. This is in sharp contrast with the rather undifferentiated microstructures found in α grains at low to medium levels of deformation. At lower reductions the annealing texture was a weak α, but the γ component increased with rolling strain and became dominant at ~80% rolling deformation. A peak type γ recrystallisation texture with orientations ranging from {554}<225> to {111}<123> was found in the 95% rolled sample. In addition to this a {411}<148> component began to intensify, reading 5R at 95% reduction. Microstructural analysis showed that DB provided the lattice curvature for nucleation in the α fibre.
Recrystallisation and Concurrent Precipitation in Hot Rolled AA3103
Authors: Miroux A. , Lok Zacharias J. , van der Zwaag Sybrand
Published: March 2009

The recrystallisation kinetics experimentally measured on a supersaturated AA3103 after hot rolling is analysed using a numerical model. It is shown that temperature and nucleation inhibition due to precipitation on the subgrain structure are the two most important parameters in controlling the recrystallisation kinetics. On the opposite, particle pinning of recrystallised grain boundaries is negligible while pinning of subgrain boundaries during recovery and solute drag are relevant but second order effects.
Effect of Grain Size on the Deformation and Dynamic Recrystallization of Mg-3Al-1Zn
Authors: Barnett Matthew R. , Atwell D. , Beer Aiden G.
Published: March 2009

The influence of grain size on the deformation of extruded Mg-3Al-1Zn tested in tension at temperatures between room temperature and 300°C is investigated. The results enable estimation of the deformation conditions for the transition from slip to twinning dominated flow and for the initiation and completion of dynamic recrystallization. A map illustrating these critical parameters is constructed and it is shown that the operating conditions of the common wrought processes straddle key transitions in microstructure behaviour.
Whisker Growth from Tin Coatings
Authors: Hutchinson W. Bevis , Oliver James , Nylén Margareta , Hagström Joacim
Published: March 2009

Conditions favouring spontaneous growth of whiskers from tin coatings are discussed. Observations are reported concerning orientations and geometry of whiskers. The driving force for growth arises from elastic stress in the coating and can be expressed as a Gibbs free energy in terms of the decrease in pressure. An analysis of diffusion-controlled growth based on grain boundary diffusion seems to be capable of accounting for the fast growth kinetics that are observed in practice
at room temperature.
Microstructural Path of Recrystallization in an Electron Beam Melted Ta-10wt% Alloy
Authors: Sandim Hugo Ricardo Zschommler , Matos B.F.S. , Fonseca G.S. , Rios Paulo Rangel
Published: March 2009

The recrystallization of an electron beam melted Ta-10wt%W alloy deformed by cold swaging with reductions in area of 41 and 95% and annealed between 1300 oC and 1700 oC is quantitatively described. The recrystallized volume fraction and the interface area per unit of volume are measured. From these quantities the microstructural path is analyzed. Based on the available measurements the nucleation and growth of recrystallization in this alloy is discussed. The kinetic analysis is difficult in this case due to the large initial grain size of the specimens.
Modelling the Softening Behaviour of Commercial AlMn-Alloys
Authors: Sjølstad Knut , Marthinsen Knut , Nes Erik
Published: March 2009

In the present work a detailed characterisation of a cold rolled and annealed AA3103- alloy has been carried out. The effect of different concentrations of Mn in supersaturated solid solution on the deformation and subsequent annealing behaviour has been studied in detail. A physically based microstructure model has been used to predict the evolution in microstructure and flow stress during annealing of the given alloy, with particular focus on the effect of concurrent precipitation on the softening behaviour.
Effect of Anisotropic Interfacial Energy on Grain Boundary Distributions during Grain Growth
Authors: Gruber Jason , George Denise C. , Kuprat Andrew P. , Rohrer Gregory S. , Rollett Anthony D.
Published: March 2009

Through simulations with the moving finite element program GRAIN3D, we have
studied the effect of anisotropic grain boundary energy on the distribution of boundary types in a polycrystal during normal grain growth. An energy function similar to that hypothesized for magnesia was used, and the simulated grain boundary distributions were found to agree well with measured distributions. The simulated results suggest that initially random microstructures develop nearly steady state grain boundary distributions that have local maxima and minima corresponding to local minima and maxima, respectively, of the energy function.
Impact of Boundary Orientation on the Motion of Curved Grain Boundaries in Aluminum Bicrystals
Authors: Ivanov V.A. , Molodov Dmitri A. , Shvindlerman Lasar S. , Gottstein Günter
Published: March 2009

The motion of <111> tilt and mixed tilt-twist grain boundaries with misorientation angles in the range between 34° and 42° in pure Al bicrystals was measured over the temperature range between 310 and 610°C. The experiments revealed that the change of the set of boundary planes in the curved moving tilt boundary does not affect its motion. The shape of the curved moving part of the mixed tilt-twist boundary was measured and compared with analytically calculated boundary
shape. The results have shown that an increase of the twist component along the curved mixed boundary in studied geometrical configuration does not affect its steady-state motion. Similar to the behaviour of <111> pure tilt boundaries, the mobility of <111> mixed tilt-twist grain boundaries in the vicinity of special misorientation å7 depends on the misorientation angle in a non-monotonic fashion.
On the Effect of “Surface Triple Junction” on Grain Boundary Motion
Authors: Ivanov V.A. , Molodov Dmitri A. , Shvindlerman Lasar S. , Gottstein Günter
Published: March 2009

The motion of a curved grain boundary with a “surface triple junction” (“free surface – boundary - free surface”) in aluminum bicrystals is studied. The effect of the “surface triple junction” on grain boundary motion is discussed in the terms of the equilibrium of boundary and junction velocity. Boundary motion in samples with different boundary curvature revealed a strict proportionality of boundary velocity and driving force. This result corroborates the fact that in the entire investigated temperature range the “surface” triple junction does not affect the boundary motion.
Effect of Triple Junctions on Grain Boundary and Grain Growth Kinetics in Aluminium - 10 ppm Magnesium Sheet
Authors: Mattissen D. , Kirch D. , Molodov Dmitri A. , Shvindlerman Lasar S. , Gottstein Günter
Published: March 2009

The motion and geometry of connected grain boundary systems with triple junctions in aluminium -10 ppm magnesium was investigated in-situ with a special designed SEM heating stage. The results show that triple junctions can have a marked influence on grain boundary motion. The grain area change with annealing time was from a hot stage in the SEM. An analysis of the experimental data reveals that there is no unique relationship between growth rate and the number n of grain sides (Von Neumann-Mullins relation). This is attributed to the effect of triple junction drag on grain growth.
Grain Boundary Structure and Its Energy of <110> Symmetric Tilt Boundary in Copper
Authors: Takata Naoki , Ikeda Kenichi , Yoshida Fusahito , Nakashima H. , Abe Hiroshi
Published: March 2009

In the present study, grain boundary energy and atomic structure of <110> symmetric tilt boundaries in copper were evaluated by molecular dynamics (MD) simulation. From the simulations, the grain boundary energy of <110> symmetric tilt boundaries depended on misorientation angle and there were large energy cusps at the misorientation angles which corresponded to (111) S 3 and (113) S 11 symmetric tilt boundaries. It was found that the atomic structure of each <110> symmetric tilt boundary was described by the combination of three kinds of structural units which consisted of (331) S 19, (111) S 3 and (113) S 11 symmetric tilt boundaries and two single crystal units which consisted of (110) S 1and (001) S 1 single crystals. From the the analysis of the excess free volume in each grain boundary, it was found that the energy of structural units depended on the excess free volume of the units and that the misorientation dependence of grain boundary energy agreed with that of the free volume in grain boundaries.
Oriented Nucleation and Selective Growth during Secondary Recrystallization in Ultra Low Carbon Steels
Authors: Verbeken Kim , Kestens Leo
Published: March 2009

After primary recrystallization, on further annealing, abnormal grain growth occurred in ultra low carbon steel. Texture evolution was studied by comparing the orientations after complete secondary recrystallization, with on one hand the nuclei for abnormal grain growth and on the other hand the selective growth products of the primary recrystallized matrix. The influence of both mechanisms could be identified in the final texture.
Investigation on the Bonding Strength between the Hard Alloy Cladding Layer and the Steel Substrate
Authors: Liu Fu Tian , Song S.X. , Yang Jun Ru , Huang Wei Ling , Li Zhao Qian
Published: March 2009

By virtue of the technology characteristics of liquid-phase sintering ternary boride hard alloy cladding material, two steel plates were bonded together by a ternary boride hard alloy cladding material through a liquid phase sintering procedure. The bonding strength between a hard alloy cladding layer and a steel substrate was characterized by means of measuring the bonding strength of two steel plates bonded by the hard alloy cladding layer. The bonding strength between hard alloy cladding layer and the steel substrate was measured by transverse rupture strength
method, tensile fracture method and single side shear method, respectively. The results show that a firm metallurgical bonding is formed during the liquid phase sintering.
Tool Condition Monitoring Based on an Adaptive Neurofuzzy Architecture
Authors: Fu P. , Hope A.D. , King G.A.
Published: March 2009

Metal cutting operations constitute a large percentage of the manufacturing activity. One of the most important objectives of metal cutting research is to develop techniques that enable optimal utilization of machine tools, improved production efficiency, high machining accuracy and reduced machine downtime and tooling costs. Machining process condition monitoring is certainly the important monitoring requirement of unintended machining operations. A multi-purpose intelligent tool condition monitoring technique for metal cutting process will be introduced in this paper. The knowledge based intelligent pattern recognition algorithm is mainly composed of a fuzzy feature filter and algebraic neurofuzzy networks. It can carry out the fusion of multi-sensor information to enable the proposed intelligent architecture to recognize the tool condition successfully.
The Advancement of SPM-Based Nanolithography
Authors: Zhang L.B. , Shi J.X. , Yuan Ju Long , Ji Shi Ming , Chang M.
Published: March 2009

Scanning probe microscopy (SPM) has proved to be a powerful tool not only for imaging but also for nanofabrication. SPM-based nanofabrication comprises manipulation of atoms or molecules and SPM-based nanolithography. SPM-based nanolithography, referred to as scanning probe lithography (SPL) in this review, holds good promise for fabrication of nanometer-scale patterns as an emerging generic lithography technique that STM, AFM, and SNOM are directly or otherwise used to pattern nanometer-scale features under appropriate conditions. Patterning methods including mechanical SPL, electrical SPL, thermal SPL, and optical SPL, are described in terms of SPL mechanisms. The newly developed variations of the above-mentioned SPL methods such as dip pen nanolithography, nanoshaving and nanografting, replacement lithography, constructive nanolithography, nanojet lithography, and electrostatic lithography, are also illustrated respectively. Analyses of prospective application of these SPL methods are presented finally.
Mathematical Description of Spatial Hob-Generating Motion for an Arbitrary Gear Tooth Profile
Authors: Feng Xian Ying , Li H. , Ai Xing
Published: March 2009

The purpose of this study is to develop a new kind of technology for the formation of an arbitrary gear tooth profile. In terms of spatial gear meshing theory, a universal transmission mathematical model for forming an arbitrary gear tooth profile has been constructed based on a standard involute gear hob. The coordinate relationship between an arbitrary point on hob cutting-edge curve and the generated point on workpiece has been deduced in detail. Hereby, an arbitrary gear tooth profile can be generated by means of computer flexible controlling each enveloped position on workpiece, and we do not need to spend so much money again to fabricate a special kind of gear cutting tool while cutting a special shape of gear tooth profile. So, this study has great economic importance, and has established the basis of generating an arbitrary gear tooth profile by means of an ordinary involute gear hob and a CNC (Computer Numerical Control) hobbing machine.
A New Type of Non-Chisel-Edge Shallow-Drill for Machining High Manganese Steel
Authors: Han Y.P. , Meng J.F. , Zhou J.Q.
Published: March 2009

A new type of non-chisel-edge shallow-drill is developed for machining high manganese steel, which is a typical hard-to-machine material. The marked characteristic of the drill is that the cutting edge is non-chisel-edge, consisting of a section of straight line and a part of curve nearby the center. The characteristics of machining performance of this drill are analyzed. Measures adopted in design for improving cutting performance and prolonging tool life are also presented. Applied
example indicates that this new drill has good cutting performances and long life. Compared with common twist drill, the axial thrust cutting force of this tool is reduced 30~50 percent.
A Study on Warm Compacting Behaviors of 316L Stainless Steel Powder
Authors: Xiao Zhi Yu , Ke M.Y. , Chen Wei Ping , Ni D.H. , Li Yuan Yuan
Published: March 2009

The application of warm compaction in stainless steel powders has not been formally
reported by now. In this paper, the warm compacting behavior of 316L stainless steel powders had been studied. Results showed that warm compaction was effective in improving the green density and strength of 316L stainless steel powders. Under the compacting pressure of 800 MPa, warm compacted density was 0.20 g/cm3 higher than cold compacted one, and green strength was 52%
higher. The optimum warm compacting temperature was 110±10°C. With die wall lubricated warm compaction, the internal lubricant content can be reduced by 0.5 wt%.
Experimental Investigation on 3D Laser Forming of Metal Sheet
Authors: Yang Li Jun , Wang Yang , Djendel M. , Qi L.T.
Published: March 2009

In this article, the relations between the formed shapes and process parameters had been studied for 3D laser forming of sheet metals. The investigation was performed on Stainless 1Cr18Ni9Ti sheet using a Nd:YAG laser source. The scanning strategies were being investigated to potentially achieve a more uniform temporal and spatial distribution of the laser energy, possibly leading to reduced part distortion, by scanning the beam across the sheet surface with both continuous and segmented irradiation geometries. The experimental results revealed that the cross spider scanning strategy could form square and circle sheets into spherical domes. And the radial lines scanning strategy could form rectangle sheets into saddle shapes. It was also apparent from the experimental results that the height of the center of the formed sheet increased with the increasing of the laser power and scanning numbers. The height of the formed square sheet firstly decreased with the laser scanning velocity increasing and began to decrease at a certain processing parameters by cross spider strategy, in which the circle sheet was opposite with the square sheet, and in which the rectangle sheet decreased with speed increasing.
Ultrasonic Machining Mechanism of Sintered Nd-Fe-B Magnetic Materials
Authors: Zhang Jian Hua , Ren Sheng Feng , Niu Zong Wei , Li Li , Xu Min Gang
Published: March 2009

The material removal mechanism of ultrasonic machining sintered Nd-Fe-B magnetic
materials was studied theoretically. The relation between critical load and central crack is given. In order to assure the material removal mode on material surface is brittle micro-fracture, the acting force of a single abrasive particle working on workpiece surface should be higher than the critical load. Experimental results show that there should be an optimal static load and an optimal abrasive size in certain ultrasonic machining system. The research results are helpful to guide practical production.
Feed Rate and Depth of Cut Influence on Cutting Forces in Diamond Turning Aluminium Alloy
Authors: Wang H.X. , Zong Wen Jun , Li Dan , Dong Shen
Published: March 2009

In this paper, a new cutting force model is presented for diamond turning, and the ‘size effect’ is also integrated into this new model. Utilizing this new model, the effects of feed rate and depth of cut on cutting forces are analyzed, the specific law of cutting forces in micro thin-layer metal cutting is investigated at the same time. Through the detailed theoretical analysis and experimental validations, it is found that if the selected feed rate or depth of cut is less than a certain value, a particular phenomenon will appear, thus the thrust cutting force Fp is greater than the principal cutting force Fc, especially when the depth of cut or feed rate is of the same order as the rounded cutting edge radius. For the micro thin- layer metal cutting, the smaller the feed rate and depth of cut, the greater is the influence of these two parameters on cutting forces.
Development of Parameters Selection System for Ultrasonic Vibration Assisted Electro-Discharge Machining
Authors: Hu Yu Jing , Zhang Jian Hua , Wang X.F. , Ren Sheng Feng
Published: March 2009

Because the machining of ultrasonic vibration assisted electro-discharge machining (UEDM) is a very complex process and it is too difficult to describe precisely every influencing factor with an accurate mathematics model, the study of parameters selection system is necessary and important for the practical application of machining method, the improvement of machining efficiency and minimizing the tool wear ratio (TWR). In this paper, the model and the corresponding database are built for UEDM based on the back propagation (BP) algorithm artificial neural network (ANN) to optimize machining parameters. Through learning and training, this system realizes the intelligent selection of machining parameters. As shown by the experiment results, the predictions accord with the test results, which shows that the reasonable and reliable project of UEDM can be provided by the system. With the increase of the machining sample, the machining database can be enriched and the application range will be expanded, so this system has the excellent fault-tolerance and extensible quality.
Investigation of Stick-Slip Effects in Wet Friction Drive Elements
Authors: Polt G. , Sebestyén T. , Pauschitz A. , Franek F.
Published: March 2009

Up to now, the suitability of uniform tractor transmission oils (UTTO) for truck and
building machine drive, brake and hydraulic systems were often investigated in expensive onvehicle or specific laboratory rig tests. Present work describes the layout and adoption of a test rig for application-oriented testing of wet brake system elements. The results gained from the tribometer experiments were compared with on-vehicle tests.
Calculation of Solidification during Continuous Casting and its Experimental Verification
Authors: Fehérvári Gábor
Published: March 2009

Two computer programs were used for simulation of continuous steel casting processes in frame of this work. In the same time industrial experiments by isotope technics were carried out for observation of solidification and shell thickness. The comparison of calculations and experimental results mutually verified the applicability of methods for more sophisticated control of continuous casting procedure.
Simulation of Precipitation of Compounds from Solid Solution by Joined Finite Difference and Cellular Automaton Methods
Authors: Geiger János , Roósz András , Barkóczy Péter
Published: March 2009

The CA method provides an excellent possibility for a lifelike simulation of
transformation processes. Using CA method the processes can be displayed on the screen of the computer as a film. CA method is widely used to simulate the transformations controlled by short-range diffusion such as recrystallisation and grain growth. At the simulation of transformations based on long-range diffusion a well-known problem is that the results of simulation depend strongly on the selected nucleus geometry and the neighbourhood of cells. In this paper the influence of neighbourhood will be analysed in the case of simulated precipitation processes. On the one hand, it is verified that an anisotropic (dendritic) structure is formed if there is no strict restriction for the computational algorithm. On the other hand, it
is demonstrated that an isotropic phase growth can be obtained by using a special simulation technique based on the joint application of finite difference (FD) and of CA methods.
Quantitative Validation of Microstructure Simulation in Case of Unidirectionally Solidified Al-Si Alloys
Authors: Kovác Jenő , Szőke János , Samu Tamás , Roósz András
Published: March 2009

The paper focuses on the microstructural investigation of Al-Si binary alloys solidified under steady- and non-steady state conditions using a unidirectional heat removal. A brief description of the developed solidification simulation software and its validation by computer aided image analysis are also given.