bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface Topography Characterization of Apatite Formation on Bioactive Glass Modified Dental Ceramics Using Confocal Laser Scanning CLSM) and Environmental Scanning Electron Microscopy (ESEM)
Authors: Stanciu G. , Stanciu S.G. , Dan C. , Paraskevopoulos Konstantinos M. , Chatzistavrou Xanthippi , Kontonasaki Eleana , Koidis Petros
Published: March 2009

Surface topography plays an important role in determining the functional performance of engineering materials as well as cell-material interactions. In this work is investigated the surface topography of an apatite layer that was developed on Bioglass® (PerioGlas® Synthetic Bone Graft Particulate, US Biomaterials)-modified dental ceramics, used in fixed prosthetic restorations, after
immersion in a Simulated Body Fluid (SBF). The visualization of the surface morphology and structure and the gradual formation of the apatitic layer were followed by CLSM, as well as by ESEM and EDS. Topography profiles on specimens’ surface revealed high surface roughness and a
fluctuation of RMS values in relation to immersion time in SBF, due to the continuing process of apatite precipitation.
Coprecipitation of Cell Adhesion Molecule with Calcium Phosphate on Hydroxyapatite Ceramic
Authors: Sogo Yu , Ishikawa Yuusuke , Kondo Nao , Uchimura Eiji , Oyane Ayako , Ohno Tadao , Ito Atsuo , Yamazaki Atsushi
Published: March 2009

Fibronectin (FN) and type I collagen (Col), which are kinds of extracelluar matrices, were coprecipitated with calcium phosphate to form a composite layer on a hydroxyapatite (HAP) ceramic using a supersaturated calcium phosphate solution (CP solution). The amounts of protein immobilized in the layers were determined to be 20.97±3.04 µg·cm-2 for FN, 5.26±0.19 µg·cm-2 for Col and 21.72±2.30 µg·cm-2 for simultaneously immobilized FN and Col. When osteoblastic
MC3T3-E1 cells were cultured on the HAP ceramics with the composite layer containing FN and/or Col, calcified tissue was formed through the activity of the cells. The result showed that the composite layer accelerated the differentiation of MC3T3-E1 to bone-forming cells. It is assumed that osteoblastic cells in alveolar bone migrated and differentiated on the surface of the tooth roots
when the artificial tooth roots were covered with the composite layer.
Mesoporous Structure and Protein Adsorption Property of c-Axis Oriented Apatite Aggregates
Authors: Ohta Kazushi , Kikuchi Masanori , Ikoma Toshiyuki , Yunoki Shunji , Monkawa Akira , Tanaka M.
Published: March 2009

Mesoporous HAp aggregates were composed of needle-like crystals that were aligned to the c-axes direction perpendicular to the flat surface of plate-like aggregates. The pore size distributions of the HAp aggregates increased with increasing heat treatment temperature e.g. 3-20 and 26-52 nm, respectively, before and after heat-treated at 600 °C. The adsorption proteins on the
mesoporous HAp aggregates were investigated by liquid chromatography using the HAp aggregates as an adsorbent. Elution molarity ratios of acidic proteins on the mesoporous HAp aggregates before and after heat-treatment at 600 °C increased with increasing molecular weight in the order of ferritin > fibrinogen > catalase > albumin, whereas the elution molarity ratios of basic proteins were considerably lower than those of acidic proteins. These results suggested that penetration of the large size acidic proteins into the pore of the as-prepared mesoporous HAp aggregate was slightly inhibited but were the proteins could easily penetrate into the pore of the heat-treated mesoporous HAp aggregates and then were selectively adsorbed on the mesoporous wall consisting of the a-surface of
the HAp aggregate. Conversely, the basic proteins could be adsorbed on the wide outer surface of the plate-like HAp aggregates. Therefore, the elution molarity ratios of basic proteins decreased with decreasing the specific surface area by the heat treatment, independent of the mesoporous structure.
Alumina Powder Containing δ, γ Crystal Phases: Evaluation of Osteoconductivity
Authors: Shinzato S. , Nakamura Takashi , Goto Koji , Kokubo Tadashi
Published: March 2009

Alumina powder containing δ , δ crystal phases (designated δAP) showed osteoconductivity. δAP was manufactured by fusing pulverized alumina powder and quenching it. The purpose of the present study was to evaluate osteoconductivity of δAP using rat tibiae. Alumina powder containing αcrystal phase (designated αAP) was used as a reference material. These two types of alumina powder were packed into the intramedullary canals of rat tibiae to evaluate osteoconductivity, as determined by an affinity index. Rats were sacrificed at 4 and 8 weeks after surgery. The affinity index, equal to the length of bone in direct contact with the powder surface expressed as a percentage of the total length of the powder surface, was calculated for each alumina powder at each interval. At 4 and 8 weeks, the affinity indices for δAP were significantly higher than those for αAP. For both δAP and αAP, there were no significant differences between the values for 4 and 8 weeks. This study revealed that the osteoconductivity of δAP was due to the alumina’s δcrystal phases. δAP shows promise as a basis for developing a osteoconductive biomaterial.
Development and Characterization of β- Tricalcium Phosphate Cements Containing Chitosan
Authors: Tonoli Marina S. , Leal Claudinete V. , Zavaglia Cecília A.C. , Beppu Marisa Masumi
Published: March 2009

Cements were prepared by mixing the calcium phosphate (β-TCP) with phosphoric acid solution (2.6M) and chitosan solution (2.5% in acetic acid solution) that was added in different proportions, ranging from 1 to 50% of total acid solution amount. Observations using SEM showed that the used of chitosan increased the interconnectivity of grains in the final cement, although the
mechanical resistance to compression decreased from approximately 3 to 1 MPa. Probably the chitosan macromolecule is able to form a more interconnected net.
Effect of Mg on Surface Roughness and Protein Content of Protein-Apatite Composite Layers
Authors: Ishikawa Yuusuke , Kondo Nao , Sogo Yu , Ito Atsuo , Uchimura Eiji , Oyane Ayako , Ohno Tadao , Yamazaki Atsushi , Ushida Takashi , Furukawa Katsuko S.
Published: March 2009

Fibronectin (FN)-apatite composite layers were formed on a hydroxyapatite (HAP) ceramic using supersaturated calcium phosphate (CP) solutions. The surface roughness of the composite layer could be controllable by changing the magnesium (Mg) concentration in the CP solution. The higher the Mg concentration, the smaller the apatite crystals in the layer were. The
thickness of the layer formed in the CP solution containing 1.5 mM Mg decreased to 68% that formed in the Mg-free CP solution. The amount of FN immobilized in the layer was almost constant regardless of Mg concentration in the CP solution in the range from 0 to 1.5 mM. The results of the present study revealed that a thin FN-apatite composite layer with a smooth surface and a high protein content is formed in a CP solution at a Mg concentration of 1.5 mM.
Preparation and In Vitro Releasing of Salmon Calcitonin Carried Porous Injectable Calcium Phosphate Bone Cement
Authors: Li Dong Xiao , Yao Q. , Fan Hong Song , Chen Ji Yong , Xiao Yu Mei , Zhang Bo , Zhang Xing Dong
Published: March 2009

Calcium phosphate cement (CPC) has many advantages and is frequently used as a carrier of antibiotic and bone growth factors. Salmon calcitonin(S-CT) is effective in treating osteoporosis. Due to its potential of promoting bone cell proliferation, S-CT was combined with injectable CPC to accelerate the restoring of the bone defect induced by osteoporosis and the composite can be used in minimal invasive surgery. Uniform design was used to optimize the
prescription, and the effects of pore-maker and S-CT on the characters of CPC were studied. The in vitro releasing of S-CT from the optimum CPC in deionized water, SBF and rabbit serum was studied with HPLC, respectively. The results showed that the contents of HA and citric acid-NaHCO3 affect the physical characters of CPC sharply, but S-CT has little effect on it. The
releasing of S-CT in three different medium follow Hugichi equation, but the speed is slower in rabbit serum than in deionized water and SBF. S-CT carried porous injectable CPC composite possesses the basic performance for clinical needs, and it is promising to be used in osteoporosis induced bone defect and accelerate bone repair.
Stiff and Tough Conductive Composites Using Carbon Black-Filled Polyethylene
Authors: Yuan Qiang , Bateman Stuart , Wu Dong Yang
Published: March 2009

Stiff and tough conductive composites were manufactured using carbon black compounded with high and low density polyethylene, as well as linear low density polyethylene. A low percolation threshold value for the composites was achieved at 2 wt% carbon black. The impact strengths of the composites incorporating low density and linear low density polyethylene were found to be almost 16 and 26 times greater, respectively, than that of high density polyethylene composites. On the other hand, the modulus of high density polyethylene filled with carbon black was 2 times as high as low and linear low density polyethylene-based composites. Tensile modulus increased with the content of carbon black, however the impact strength of the composites decreased.
A Finite Element Analysis of a Crack Penetrating or Deflecting into an Interface in a Thin Laminate
Authors: Kao-Walter Sharon , Ståhle Per , Chen Shao Hua
Published: March 2009

The crack tip driving force of a crack growing from a pre-crack that is perpendicular to and terminating at an interface between two materials is investigated using a linear fracture mechanics theory. The analysis is performed both for a crack penetrating the interface, growing straight ahead, and for a crack deflecting into the interface. The results from finite element calculations are compared with asymptotic solutions for infinitesimally small crack extensions. The solution is found to be accurate even for fairly large amounts of crack growth. Further, by comparing the crack tip driving force of the deflected crack with that of the penetrating crack, it is shown how to control the path of the crack by choosing the adhesion of the interface relative to the material toughness.
Monte Carlo Simulation of Microstructure and Grain Growth in nc-Ti(N, B)/a-(TiB2, BN) Nanocomposite Films
Authors: Shen Yao Gen , Liu Z.J. , Lu Y.H. , Lu Chun Sheng , Mai Yiu Wing
Published: March 2009

A combination of high-resolution transmission electron microscopy and x-ray
photoelectron spectroscopy are used to establish that Ti-B-N films with different boron concentrations prepared by reactive unbalanced magnetron sputtering exhibit a two-phase nanocomposite microstructure, showing nanocrystalline Ti(N, B) grains embedded in amorphous (TiB2, BN) matrices. Using Monte Carlo simulations and based on a simple model employing a kinetic grain growth theory, we also investigate the effects of the amorphous TiB2-BN phase on the microstructure evolution and grain growth in nanocrystalline-Ti(N, B). Our study demonstrates that the formation of such an amorphous phase at the grain boundary could hinder the growth of Ti(N, B) grains and the mean grain size shows an exponential decay with boron concentration, in good agreement with our experimental observations.
Preparation of Mesoporous Silicate Thick Films by Electrophoretic Deposition and Their Adsorption Properties of Water Vapor
Authors: Negishi Hideyuki , Endo Akira , Nakaiwa Masaru , Yanagishita Hiroshi
Published: March 2009

Ordered mesoporous silicate (MPS) is one of the most promising adsorbents for
energy-efficient adsorption systems such as desiccant cooling systems, because it can be recovered by
low-temperature exhaust heat at less than 100 °C. The electrophoretic deposition (EPD) technique
was investigated for the fabrication of a thick film. A particle/acetone suspension could be applied
and the dispersed particles become negatively charged. A MPS powder can be deposited by EPD at
50 V for 10 min onto 15.7 cm2 of a tubular metal substrate and more than a 200 μm thick uniform
coating was obtained. After heat treatment at 300 °C, the MPS powder can be fixed on the substrate
without the addition of binders. The obtained thick film of MPS possessed the same porous structure
and properties regarding the adsorption of water vapor showed almost the same as that of the powder
sample.
Micropatterning of Phenylsilsesquioxane Thick Films by the Electrophoretic Sol-Gel Deposition Process Using ITO Substrates with a Hydrophobic-Hydrophilic Patterned Surface
Authors: Tadanaga Kiyoharu , Takahashi Kenji , Tatsumisago Masahiro , Matsuda Atsunori
Published: March 2009

Micropatterns of phenylsilsesquioxane thick films have been prepared by electrophoretic sol-gel deposition using ITO-coated substrates with a hydrophobic-hydrophilic patterned surface. After the electrophoretic deposition, phenylsilsesquioxane thick films were formed only on hydrophilic areas on the pattern. These thick films obtained immediately after the electrophoretic deposition were opaque due to light scattering. However, phenylsilsesquioxane particles in the films were morphologically changed from aggregates of the spherical particles to continuous phase by a heat treatment process, and finally convex shaped phenylsilsesquioxane micropatterns were formed only on the hydrophilic areas.
Development of Ceramic Dental Crowns and Bridges Using Electrophoretic Deposition
Authors: Moritz Tassilo , Linaschke Dorit , Eiselt W.
Published: March 2009

In the dental branch much effort is undertaken for production of metal-free ceramic restoration. Because of esthetical aspects and their biocompatibility ceramics are the material of choice. Allergic reactions or toxic tissue damages can be prevented largely by application of ceramic dental products. Zirconia in its tetragonal yttria stabilized polycrystal form (TZP) and alumina toughened zirconia (ATZ) offer highest strength combined with highest toughness. Unfortunately this favourable, outstanding combination of mechanical properties leads to difficulties in conventional hard machining in the sintered state, which is too time- and costconsuming. For this reason, electrophoretic deposition of alumina toughened zirconia powder and TZP powder was used for preparation of metal-free dental crowns and bridges. The electrophoretic deposition process was carried out directly onto the plaster moulds for single crowns, three-unit and four-unit bridges. The electrophoretic deposition process was investigated concerning the deposition rate and the output of dental crowns per volume of ethanolic ceramic suspension. Furthermore, the influence of the amount of dispersing agent on the rheological properties of the ceramic suspensions was investigated.
Electrophoretic Deposition as a Novel Near Net Shaping Technique for Functionally Graded Biomaterials
Authors: Anné Guy , Vanmeensel Kim , Vleugels Jef , Van der Biest Omer
Published: March 2009

Due to their excellent properties of high strength, biocompatibility and stability in physiological environments, ceramics are investigated as bone substitute materials. In this way ceramic components have been used for total hip replacement components since the early 1970s. Alumina and zirconia monoliths are mainly used for these components. However, zirconia can undergo low temperature degradation in aqueous environment and alumina is brittle. To increase the strength, functionally graded Al2O3/ZrO2 ball-heads and acetabular cup inserts were made in this work by electrophoretic deposition (EPD). A composition gradient in alumina and zirconia was engineered to obtain a pure alumina surface region and a homogeneous alumina/zirconia core with intermediate continuously graded regions to generate thermal residual stresses at the surface after sintering. Experimental work revealed that a sequence of counter-electrodes was necessary to EPD complex shaped functionally graded material (FGM) components. To obtain deposits with a shape different from the deposition electrode, the deposit was grown up to the counter-electrode and the design of the counter-electrodes was supported by electrical field calculations to generate a constant electric field at the surface of the deposition electrode
Electrophoretic Deposition of Wollastonite on 316L Stainless Steel from Different Dispersing Media
Authors: Rodríguez Hugo H. , Vargas Gregorio , Cortés-Hernández Dora A.
Published: March 2009

Natural wollastonite was electrophoretically deposited on 316L stainless steel in order to
promote a bioactive surface. The effect of the disperse media and the deposition time on the deposit
weight and microstructure of the wollastonite coatings was evaluated. The disperse media were
methanol, acetone, ethanol, propyl alcohol and the deposition time was in the range of 1 to 180 s.
Suspensions were prepared by using wollastonite powder with a mean particle size of 2 μm at a
concentration of 1 g/L. The deposition was performed under a DC field of 800 V. The coated
substrates were sintered at temperatures ranging from 900 to 1050oC in air for 2 to 4 h. Dense,
homogeneous and crack-free coatings were obtained by using methanol and acetone. No
wollastonite coating was obtained by using ethanol at these processing conditions and few
wollastonite particles were deposited on the metallic substrates by using propyl alcohol. The deposit
weight increases as the deposition time is increased in all the cases.
Electrophoretic Deposition of Nanocrystalline SiC Ceramics
Authors: Wildhack S. , Aldinger Fritz
Published: March 2009

In the present contribution, the electrophoretic deposition (EPD) of nanocrystalline SiC
powders will be discussed. In order to avoid the electrolysis of water during deposition as well as
oxygen uptake of the nanocrystalline SiC by hydrolysis reactions, nonaqueous solvents were tested
including ethanol and diethyl formamide. The solvents were compared regarding their effect on
particle size distributions and sedimentation tests. Auxiliary information on the surface conditions
as a function of the acidity of the suspension was drawn from aqueous zeta-potential measurements.
The influence of dispersants, binders and the type of powder on the suspension properties was
studied, and EPD was performed. For promising solvent-dispersant systems, the film thickness,
current and deposition time at a given voltage were monitored during EPD.
Sawing of Granite with Side-Slotted Diamond Segments
Authors: Yu Yi Qing , Zhang Y.F. , Li Yuan , Xu Xi Peng
Published: March 2009

The present study was undertaken to examine the feasibility of circular sawing of granite
with a newly shaped diamond saw blade. Three slots were formed on each side of each segment of the
saw blade. Side-slotted segments and traditional segments were compared under same operating
parameters. Measurements were made of the horizontal and vertical force components and the
consumed power in order to obtain the tangential and normal force components. The surfaces of worn
blade segments were examined by a scanning electron microscope. The consumed powers, normal
and tangential force components for the side-slotted segments were found to be lower than those of
the traditional segments. The position of resultant forces for the side-slotted segments is a little further
away from the bottom of the cutting zone than the traditional segments. SEM observations indicated
that the wear of the side-slotted segments was similar to sawing with traditional segments.
Study on the Wear and Breakage of PCD Tools for Turning Si-Al Alloy Pistons
Authors: Zhang Jian Hua , Zhang X.H. , Li Li , Shang Z.H. , Bai W.F.
Published: March 2009

As its hardness and wear resistance being approximate to that of natural diamond,
polycrystalline diamond (PCD) is a kind of perfect tool material for cutting Si-Al alloy pistons. In
the turning process of Si-Al alloy pistons, the normal wear of PCD tools is a continuous and gradual
process, which mainly is hard grain wear, as well as adhesion wear, diffusion wear, and chemical
wear. The breakages of PCD tools include collapse, crash and flake etc, which occur mainly in
discontinuous turning process. Experimental results and production statistic indicate that about
40~55% of PCD tools failure is breakage in discontinuous turning process of Si-Al alloy pistons.
Reducing impact load is the main method to avoid tool breakage.
Effect of Nano-Scale Al2O3 on Mechanical Properties of TiB2 Ceramic Tool Materials
Authors: Gu M.L. , Huang Chuan Zhen , Wang Jun
Published: March 2009

In this paper, a TiB2 composite with nano-scale Al2O3 as dispersion phase was
hot-pressed at 1750. The effect of nano-scale Al2O3 on sinterability and mechanical properties of
the TiB2 was investigated. The results show that the relative density of sintered body increases
firstly and then decreases with the increasing of the Al2O3 content. When containing 10vol%
nano-scale Al2O3, the composite with fine and uniform grains is obtained and the flexural strength
reaches maximum. The nano-scale Al2O3 may agglomerate together when the Al2O3 content is up to
20vol%, which is harmful to the densification and mechanical properties of the composite.
Study on the Mechanism of the Continuous Composite Electroplating Polishing for Silicon Wafer
Authors: Zheng Jia Jin , Zhou Zhao Zhong , Yuan Ju Long , Zhao Ping
Published: March 2009

The pad is one of the key factors in the chemical-mechanical planarization (CMP) process. To ensure the machining capability and the quality of workpieces, the pad must be conditioned in the process. It will cause the pad thiner, and be replaced by a new one for losing the machining capability finally. For this reason, a new method of CMP by using the continuous composite electroplating on the polishing disc is introduced. In this process, the machining ability of the pad can be ensured due to the continuous Sn-SiO2 composite electroplating. The effect of cathode current density and time of plating on the characteristics of composite coating and silica wafer are investigated. The experiment indicates that the continuous composite electroplating polishing (CCEP) is an efficiency method for polishing silicon wafer, and the surface roughness of the silicon wafer is 0.005μm
Cutting Parameters Optimization of High-Speed Milling of Thin-Walled Graphite Electrode
Authors: Hu Z.L. , Wang Cheng Yong , Zhou L. , Fu H. , Chen J.
Published: March 2009

Graphite electrode material has been extensively used for thin-walled electrode
manufacturing, due to its typical brittleness, HSM becomes the main process method to obtain
higher productivity and good surface finish. According to the structure characteristics of the
thin-walled graphite electrode and the problems arising in its high-speed milling, through
high-speed milling experiments, researches have been done into the effect of the main cutting
parameters on cutting forces, which include cutting speed, feed per tooth, radial cutting depth, axial
cutting depth, down or up milling. Finally, cutting parameters optimization strategies of high-speed
milling of thin-walled graphite electrode aiming to obtain higher efficiency and high quality are
presented as follows: down-cut mode, moderate radial depth of cut and flat endmill should be
adopted in high-speed milling of graphite electrode.
Balling Process in Selective Laser Sintering 316 Stainless Steel Powder
Authors: Shen Yi Fu , Gu D.D. , Pan Y.F.
Published: March 2009

Balling process in selective laser sintering of 316 stainless steel powder was investigated. It showed that the balling phenomenon was ascribed to the higher liquid viscosity and surface tension effect during laser sintering. The effects of laser power and scan speed on the balling initiation was studied. It was found that increasing laser power and scan speed within a moderate range can reduce balling effect. However, care should be taken to control laser powers and scan speeds that can be used since their excessive increase may give rise to detrimental effects.
Research and Development of High Speed Cutting Tribology
Authors: Ai Xing , Zhao Jun , Liu Zhan Qiang , Deng Jian Xin , Liu J.G.
Published: March 2009

Due to large deformation, high pressure and high temperature, the tribological behavior
between tool and workpiece in high speed cutting is markedly different from that between
mechanical parts. High speed cutting tribology is a interdependent scientific discipline, in which
kinematics and friction between tool and workpiece, tool wear and fracture, match of mechanical,
physical and chemical properties of materials between tool and workpiece, as well as influences of
cutting conditions and external environment (such as air, cutting fluids) on tribology and machined
surface are investigated. The discipline of high speed cutting tribology is the science base for tool
materials design and predicting the tool life, surface integrity and cutting accuracy for high speed
cutting. In this paper, the concept of high speed cutting tribology and its research development and
prospect are presented.
Study on EDM Polishing of CVD Diamond Films
Authors: Lu Wen Zhuang , Zuo Dun Wen , Wang Min , Xu Feng , Li Xiang Feng
Published: March 2009

Chemical vapor deposition (CVD) diamond is known for its superior characteristics such
as hardness, toughness and wear resistance. However, due to these factors, machining CVD
diamond is a difficult material removal process. A new technique to polish CVD diamond film
efficiently is reported in the present paper. In the CVD deposition process, boron was doped into
diamond to fabricate high-quality semi-conductive film, which make it possible to machine
diamond film by electro discharged machining (EDM) method. The relationship between EDM
parameter and removal processing was investigated in details. The machined surface of boron
doped (B-doped) diamond films was studied by Scanning Electron Microscope (SEM) and Raman
Scattering Spectroscopy (Raman). The experimental results show that EDM polishing is a highspeed
material removal and low cost method for CVD diamond polishing. When the discharge
current and pulse-on time increase in a certain range, the cutting-off speed and roughness will
increase correspondingly. The roughness of EDM polished CVD diamond film surface is Ra<0.5μm
when the discharge current is at 4A and pulse-on time is at 200μs.
Researches and Simulations on Hydrodynamic in Super High Speed Grinding Area
Authors: Gong Ya Dong , Li H. , Zhao X.X. , Wang Wan Shan
Published: March 2009

It analyzed the conditions in hydrodynamic action of coolant in super high speed grinding area and described the conception of lubricate induce force in the paper. Using fluid dynamical lubrication theory, theory analyses and mathematics modeling on lubricate induce force in plane grinding with non-porous grinding wheel were carried out, also the computer simulations were done, and the conclusion was theoretically verified by tests in interrelated material documents. On the bases of this, by analyzing the effects of parameters and pointing out grinding wheel speed, grinding wheel width significantly influences the max dynamic pressure in grinding area, thus the analyses indicated that it rises with the speed of grinding wheel increasing.
Development of a New Virtual Environment System for Assembly
Authors: Liu G.H. , Yao Ying Xue , Zhang H.Z.
Published: March 2009

In order to make the operator freely walk in virtual environment (VE), a new prototype of
VE system for assembly is presented in this paper. In this system, a special machine is designed and
it enables the operator to walk inside the VE in any directions over a long distance without actually
leaving the physical device. Images produced by the computer are projected upon the surface of a
large spherical cap screen surrounding the operator by means of a group of high power projectors.
Signals provided by the position sensors attached to the operator are used by the computer to update
the projected images, which provides the operator the illusion of walking freely through the virtual
scenes. This VE system can acquire wide field of view and form panorama surrounding the operator,
which may enhance the realistic sense of simulation.
Tool Wear Characteristics in High Speed Milling of Ti-6Al-4V Alloy with Nitrogen Gas Medium
Authors: Zhao Wei , He Ning , Li Liang , Man Z.L.
Published: March 2009

High speed milling experiments using nitrogen-oil-mist as cutting medium were undertaken to investigate the characteristics of tool wear for Ti-6Al-4V Alloy, a kind of important and commonly used titanium alloy in the aerospace and automobile industries. Uncoated carbide tools have been applied in the experiments. The cutting speed was 300 m/min. The axial depth of cut and the radial depth of cut were kept constant at 5.0 mm and 1.0 mm, respectively. The feed per tooth was 0.1 mm/z. Optical and scanning electron microscopes have been utilized to determine the wear mechanisms of the cutting tools, and energy spectrum analysis has been carried out to measure the elements distribution at the worn areas. Meanwhile, comparisons were made to discuss the influence of different cutting media such as nitrogen-oil-mist and air-oil–mist upon the tool wear. The results of this investigation indicate that the tool life in nitrogen-oil-mist is significantly longer than that in air-oil-mist, and nitrogen-oil-mist is more suitable for high speed milling of Ti-6Al-4V alloy than air-oil-mist.
Investigation of Manufacturing Technology in Electroplating CBN on Gear-Honing-Tool
Authors: Lv Ming , Zhang Man Dong , Ya Gang , Xu P.
Published: March 2009

In the paper, a new technology combining conventional CBN electroplating and thermal
diffusion in vacuum to produce gear-honing-tool for hardened tooth is introduced. The two factors,
such as planting CBN abrasives and combination between electroplating layer and matrix that can
affect the quality of gear-honing-tool, are investigated. Experiments show that using suspension
CBN abrasive electroplating combined with thermal diffusion in vacuum can ensure the quality of
planting CBN abrasives of gear-honing-tool and obtain the semi-metallurgy binding layer between
CBN abrasives and matrix that withstands the force of honing gears.
Study on the Adhering Disrepair and Groove Optimization of Cutting Tools for Difficult-to-Machine Materials
Authors: Li Zhen Jia , Cheng Yao Nan , Tan Guang Yu , Wang Yan Bo , Rong Yi Ming
Published: March 2009

In the course of the milling experiments with the difficult-to-machine material
3Cr-1Mo-1/4V steel, we have found the substance of the adhering disrepair. In addition, we forecast
the predominant capability of the waved-edge milling insert with complex 3-D grooves by the
synthetically blurry judgement. Eventually, we give the mathematical model between the milling
temperature and the maximal adhering disrepair depth of the rake face, and analyze the rule that the
milling temperature affects the adhering disrepair. What’s more, we testify the predominant
capability of the waved-edge milling insert.
Experimental Research on Technology of Ultrasonic Vibration Aided Electrical Discharge Machining (UEDM) in Gas
Authors: Zhang Qin He , Zhang Jian Hua , Zhang Q.B. , Su Shu Peng
Published: March 2009

Ultrasonic vibration aided electrical discharge machining (UEDM) in gas is an electrical
discharge machining (EDM) technology, in which gases such as air and oxygen are used as dielectrics
and ultrasonic vibration is applied. UEDM in gas can avoid environment pollution, the most serious
disadvantage of conventional EDM in kerosene-based oil or other dielectric fluids, and it is
environmental-friendly. The technology also possesses virtues of wide applications, high machining
efficiency and simple tool electrodes and so on. The principle of UEDM in gas is introduced in this
paper. Experiments have been carried out to study the effects of machining parameters on material
removal rate (MRR), surface roughness of the workpiece and tool electrode wear ratio (TWR), and
the experiments results have also been analyzed.
Study on Comparative Experiments of Performance of Conventional and Nanocrystalline Diamond Film
Authors: Chen Ming , Ma Y.P. , Xiang Dao Hui , Sun Fang Hong
Published: March 2009

Nanocrystalline diamond film with smooth surface and uniform grains was deposited
successfully on Co-cemented carbide using the bias-enhanced hot filament chemical vapor deposition
(HFCVD). The surface morphology and chemical quality of film were estimated by scanning electron
microscopy (SEM), atomic force microscopy (AFM) and Raman spectroscopy. Comparative
experiments of tribological and wear performances of conventional and nanocrystalline diamond
films were carried out by pin-on-disc tester. The research results show that nanocrystalline diamond
film with good tribological performance and high quality can be deposited by regulating the
deposition parameters on Co-cemented carbide. The film not only has high adhesive strength but also
has smooth surface, low surface roughness, low friction coefficient. The work done in this paper
provide the wide application of diamond on complex shape tools, drawing dies and other wear
resistant device with experimental reference.
Volumetric Positioning Errors of CNC Machining Tools and Laser Sequential Step Diagonal Measurement
Authors: Shen J.H. , Zhang H.T. , Cao Hong Tao , Yang Jian Guo , Wang C.
Published: March 2009

The volumetric positioning precision of CNC machine tools is the key factor to get high machining precision, so the analysis, measurement and compensation of the volumetric error is becoming more and more important. In this paper, the modeling results of 3-axes CNC machine tools with four different configurations are given based on rigid body theory and homogeneous coordination transformation matrices. An improved sequential step diagonal measurement method is proposed and analyzed because the current laser measurement methods are complex and time cost. At the final section of the paper, the measurement data was applied into the error compensation and the sequential step diagonal measurement method was validated efficient and convenient.
Fabrication of Si3 N4-TiN Nanocomposites via Various Routes
Authors: Hojo Junichi , Kugimoto Hironori , Uehara Masato , Enomoto Naoya
Published: March 2009

Si3N4-based composite powders have been synthesized by vapor phase and liquid phase
processes. Nano-sized Si3N4-TiN composite particles were formed by the vapor phase method, in
which TiN nanocrystallites were included in amorphous Si3N4 particles. The composite powder was
also formed by the liquid phase method, where Si and Ti complex imide powders were prepared in
an organic solvent and decomposed by heating. Si3N4-TiN nanocomposites were fabricated by hot
pressing of the composite powders. The Si3N4-TiN composites were also fabricated by in-situ
process from amorphous Si3N4 and Y2O3-TiO2-AlN additive. In all processes, rod-like Si3N4 grain
growth was stimulated by TiN inclusion.
Conventional Sintering Route for the Production of Alumina-Based Nanocomposites: A Microstructural Characterization
Authors: Palmero Paola , Esnouf Claude , Montanaro Laura , Fantozzi Gilbert
Published: March 2009

Two α-Al2O3/YAG composite powders have been prepared by reverse-strike
precipitation, starting from chlorides aqueous solutions, the former containing 50 vol% of the two
phases (labelled as AY50) and the latter made of 90 vol% of alumina and 10 vol% of YAG (AY90).
The as-prepared powders were characterised by DTA/TG simultaneous analysis as well as by XRD
analysis performed after calcination at different temperatures. A systematic TEM analysis was
performed on AY50 powders pre-treated at different temperatures, in order to investigate the
crystallites size evolution as a function of the temperature. After that, samples were compacted by
uniaxial pressing and sintered at 1600°C for 3h. SEM observations revealed a homogeneous
microstructure made of micronic alpha-alumina and YAG grains. For limiting grain growth through
the decreasing of the maximum sintering temperature, an innovative activation procedure by
coupling suitable thermal and mechanical treatments of the powders was performed. After that, high
densification (>95% of the theoretical density) was easily achieved by performing a free sintering in
the temperature range between 1320° and 1420°C, with different soaking times at the maximum
temperature. The resulting sintered bodies showed an effective retention of the nano-size of the
primary particles. By SEM, highly-homogeneous nanostructures, with an average grains size of
about 200 and 300 nm for AY50 and AY90, respectively, were observed.
Critical Frontal Process Zone Size and R-Curve Behavior of Porous Ceramics
Authors: Awaji Hideo , Chen Chun Hong , Kishi Nobuyuki
Published: March 2009

Although porous ceramics are materials with high potential for helping conserve the
environment, the characteristics of pore-related mechanical properties have not yet been examined
sufficiently. The R-curve behavior of porous ceramics was estimated using the crack stabilizer
technique developed by Nojima et al. Also, the critical frontal process zone (CFPZ) size for porous
ceramics was estimated from the strength and fracture toughness of the materials used. The results
revealed that the R-curve behavior was almost flat in porous ceramics, in contrast with a steeply rising
R-curve behavior for porous silicon carbide observed previously, and that the CFPZ size of porous
ceramics was larger than that of dense ceramics. A schematic explanation for the crack extension in
porous materials was presented to discuss the R-curve behavior of porous ceramics.
Mechanical Properties of Sol-Gel Inorganic-Organic Hybrid Films in Nanoindentation
Authors: Zhang J.Q. , Matsuda Atsunori , Muto Hiroyuki , Sakai Mototsugu
Published: March 2009

Methylsilsesquioxane films were formed on glass substrates by dropping a sol prepared
from methyltriethoxysilane and then heat-treated in an oven. Nanoindentation test was performed to
assess the elastoplastic properties of the films, including the relative residual depth ξr, Meyer hardness
HM, work-of-indentation WI and the elastic modulus E’. The values of ξr, HM and WI were obtained by
a Berkovich indenter and E’ was determined by a spherical indenter on the basis of Hertz elastic
theory. ξr decreased with the increase in the heat treatment time, whereas HM , WI and E’ significantly
increased with the time. The changes in the mechanical properties with the heat treatment time well
reflected the evolution of the Si-O-Si network structure in methylsilsequioxane film.
Superplastic Behavior in GeO2 - TiO2 Doped TZP
Authors: Ito H. , Yoshida Hidehiro , Ikuhara Yuichi , Yamamoto Takahisa , Sakuma T.
Published: March 2009

Superplastic behaviors were investigated for fine-grained yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) from a viewpoint of GeO2 or TiO2 doping. It was found that both dopants enhance the ductility in TZP. In particular, elongation to failure of 988% could be obtained in 3Y-TZP co-doped with 2mol%GeO2 and 2mol%TiO2. In addition, it was revealed that lower flow stress did not always give a larger elongation in this system. On the other hand, the strong segregation of dopants along grain boundaries was confirmed by high-resolution electron transmission microscopy study (HRTEM) with X-ray energy dispersive spectrometer (EDS). The unique phenomena observed in the relation between flow stress and ductility is closely related to the strong segregation of dopants along grain boundaries in this system. The grain size at fracture is determined by covalency because of the dopant segregation. It could be concluded that elongation to failure is closely related to a balance between grain size at fracture and grain growth rate during deformation.
Microstructure and High Temperature Strength Characteristics of Unidirectionally Solidified Al2 O3 /GdAlO3 Eutectic Composite
Authors: Ohtsubo Hideki , Nakagawa Narihito , Shimizu Kazutoshi , Shibata Koji , Mitani Atsuyuki , Waku Yoshiharu
Published: March 2009

Enploying unidirectional solidification, Al2O3/GdAlO3(Gadolinium Aluminum
Perovskite:GAP) eutectic composite was fabricated. The Al2O3/GAP eutectic composite obtained
has a flexural strength of over 600Mpa above 1500C. The composite also showed plastic
deformation above 1550C on the flexural test. The effect of microstructure on mechanical strength
at high temperature was investigated. Al2O3/GAP eutectic composites having different
microstructure were fabricated by controlling the temperature gradient on unidirectional
solidification. It was found that the flexural strength at high temperature of the composite became
higher with refining the microstructure.
Development and Evaluation of Ceramic Components for a Gas Turbine
Authors: Fukudome Takero , Tsuruzono Sazo , Tatsumi Tetsuo , Ichikawa Yoshihiro , Hisamatsu Tohru , Yuri Isao
Published: March 2009

An 8000 kW class Hybrid Gas Turbine (HGT) project, administered by the New Energy and Industrial Technology Development Organization (NEDO), was completed in March 2004. The targets of this project were improvement in thermal efficiency and output power by using ceramic components, and early commercialization of the gas turbine system. The ceramic components were used for stationary parts subjected to high temperature. It became clear that silicon nitride material showed significant recession under combustion gas. Kyocera and Central Research Institute of Electric Power Industry developed new EBCs to suppress this recession. These EBCs were evaluated by exposure test, heat cycle test and actual HGT engine test. One of the EBCs showed slight defects after the actual engine tests. However, all EBCs showed high corrosion resistance and good adhesion. It was confirmed that the all EBCs worked effectively.
Macroporous Ceramics Coated with Mesoporous Layer for Enzyme Encapsulation
Authors: Seelan Sindhu , Kato Katsuya , Yokogawa Yoshiyuki
Published: March 2009

Mesoporous silica with 5~10 nm pore size was coated over recycled ceramic, prepared from lake sludge, with pore size 100-200μm. The mesoporous silica coated ceramic was characterized by XRD, N2 sorption, SEM and TEM. The results clearly showed the formation of mesoporous coating on the macroporous ceramics. These ceramics with the mesoporous coating are specially suitable for stabilization of enzymes. The mesopore stabilized enzymes are recyclable catalysts and showed comparable performance with the free enzyme.
Evaluation of Energy Consumption in Ceramic Fabrication Process for Alumina Ceramics with Diverse Particle Sizes
Authors: Nagano Sachie , Watari Koji
Published: March 2009

In order to develop low-energy ceramic processing, we evaluated the energy consumption
of total fabrication processes of alumina ceramics with various particle sizes. It is demonstrated that
the optimum particle size is several tens of nanometers for energy-saving, and decreasing particle size
from 400 to 40 nm enables the 40 % energy reduction in this assessment.
Finite Element Analysis on Proof Testing of Ceramic Ball Heads for Total Hip Replacements: Trauma Loading Considerations
Authors: Carillo Daniel G. , Curiel M.C. , Aum Ho Sung , Lee Soo Wohn
Published: March 2009

Trauma related loading of hip prostheses has been reported as a cause of failure of
implanted ceramic materials, ball and/or cup. In this study a computer simulated model is made to
evaluate contact pressures and stresses in the stem/ball contact pair, as well as stress concentration
regions in the ceramic cup. A 3D Non-Linear Finite Element Analysis was performed in a “proof
test” scenario. A high peak trauma-like loading of 15 KN was used. 28mm ball heads (in diameter)
were modeled and two sizes for taper lock were simulated to report their influence on the contact
pressure over the critical areas of the ballhead. It was found that the ball head cone’s depth has a
major incidence in the stress and contact pressure surrounding the stem when an impact load is
applied. The best stress and pressure configurations were found for the case of the stem lying
completely inside the ballhead.
Thermoelectric Properties of Al-Doped ZnO Prepared by Electrical Field-Assist Sintering
Authors: Kaga Hisashi , Asahi Ryoji
Published: March 2009

Al-doped ZnO ceramics were fabricated by the electrical field-assist sintering method
and their thermoelectric properties were examined. When the current density of 10A/cm2 was
applied, the electrical conductivity was increased by about 30 % compared with that of a specimen
set in the same furnace without any applied current. The Seebeck coefficient was also increased by
approximately 10%. The power factor was thus improved about 60%, reaching 1.3x10-3 W/mK2 at
1053K, which is one of the best power factor in bulk oxides. Analyses of Hall measurement and
thermal conductivity showed that longer mean free paths of both electrons and phonons were
obtained by the electrical field-assist sintering method, suggesting promotion of the grain growth
and/or reduction of barriers at the grain boundary in the direction of current.
Processing and Mechanical Properties of Microcellular Ceramics
Authors: Kim Young Wook , Kim Shin Han , Park Chul B. , Kim Hai Doo
Published: March 2009

Recently, a novel processing route for fabricating microcellular ceramics has been developed. The strategy for making the microcellular ceramics involves: (i) forming some shapes containing a mixture of preceramic polymer, expandable microspheres and optional fillers by a conventional ceramic forming method, (ii) foaming the compact by heating, (iii) cross-linking the foamed body, and (iv) transforming the foamed body into microcellular ceramics by pyrolysis. The flexural strength and compressive strengths of the microcellular ceramics were investigated; values up to 30 MPa and 100 MPa, respectively, were obtained at room temperature. The superior mechanical properties were attributed to homogeneous distribution of cells in microcellular ceramics.
Damping Characteristics of Cold-Rolled and Annealed Equiatomic TiNi Shape Memory Alloy
Authors: Chang S.H. , Wu Shi Kang
Published: March 2009

Damping capacity and storage modulus of cold-rolled and annealed Ti50Ni50 SMA are
systematically investigated by DSC and DMA tests. The specimens annealed at 500 oC for 1 ~ 72 h
and annealed at 650 oC for short time can all reach a high tan δ value and a deep storage modulus
minimum during B2→R transformation. This reveals that the occurrence of R-phase can strongly
soften the storage modulus and thus promote the damping capacity of Ti50Ni50 SMA. The specimens
anneaed at 650 oC for longer time have a lower tan δ value due to the diminishing of R-phase
formation. Therefore, a good damping capacity associated with a significant softening storage
modulus can be acquired by suitably control the annealing conditions of cold-rolled Ti50Ni50 to
generate adequate of R-phase premartensite.
Preparation and Characterization of Porous Alumina Film Using Sol Containing PEG
Authors: Miki Takeshi , Nishizawa Kaori , Suzuki Kazuyuki , Kato Kazumi
Published: March 2009

To obtain porous alumina films, the precursor sol was prepared by hydrolysis of Al isopropoxide and then mixing with poly(ethylene glycol) (PEG). The porous alumina films were fabricated by dip-coating technique on glass substrates and heating at 500 °C. The film was composed of nano sized particles (30-50 nm). The maximum thickness of the film prepared by one-run dip-coating was ca. 1000 nm. The film had humidity-sensitive electrical resistance at room temperature.