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National Institute for Materials Science

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[Functionally Graded Materials VIII (FGM2004) (pp.267-528)](https://mdr.nims.go.jp/datasets/0306068f-95c4-4d42-a053-57d37a58603a)

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Sheet1 BookTitle_j BookTitle_e Volume/Issue Issueddate Page Title_j Title_e AuthorList_j AuthorList_e Abstract Language Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 267-272 CVD-ダイヤモンド層におけるDNAフラグメントの正面固定化 Head-on Immobilization of DNA Fragments on CVD-Diamond Layers S.Wenmackers, P.Christiaens, W.Deferme, M.Daenen, K.Haenen, M.Nesladek, P.Wagner, V.Vermeeren, L.Michiels, M.vandeVen, M.Ameloot, J.Wouters, L.Naelaerts, Z.Mekhalif S.Wenmackers, P.Christiaens, W.Deferme, M.Daenen, K.Haenen, M.Nesladek, P.Wagner, V.Vermeeren, L.Michiels, M.vandeVen, M.Ameloot, J.Wouters, L.Naelaerts, Z.Mekhalif  Synthetic diamond is regarded as a promising material for biosensors: it forms a stable platform for genetic assays and its biocompatibility for in vivo sensing. In this study the use of a thymidine linker for covalent DNA attachment was evaluated. Contact angle measurements provided a qualitative test of the initially oxidized surface. X-ray photoemission spectroscopy was used for further analysis of the initially oxidized surface. X-ray photoemission spectroscopy was used for further analysis of the oxides and for monitoring the effect of subsequent chemical treatments. The presence of FITC-labelled DNA was confirmed by confocal fluorescence microscopy. Enzyme linked immunosorbent assays indicated that this DNA was merely adsorbed on the diamond surface instead of covalently bound. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 273-278 熱電適用のためのBi2Te3およびFeSi2の積層 Stacking of Bi3Te3 and FeSi2 for Thermoelectric Applications Cestmir Drasar, Eckhard Muller Cestmir Drasar, Eckhard Muller  Recently, there is a strong interest in developing superior thermoelectric materials with the aim to improve the performance of a device. However, the performance of a thermoelectric generator (TEG) can be considerably improved also by applying a graded composition along the temperature gradient inside the thermoelectric device so that at each position the respective material achieves its maximum thermoelectric performance (TE FGM principle). Combining the high efficiency of Bi2Te3 (used at low temperatures) and general durability of FeSi2 (applied up to high temperatures) will result in a thermoelectric device with enhanced efficiency operating in air at a wide temperature range. The challenge is to contact these dissimilar materials without any negative impact on the performance of TEG. Besides providing a good electrical and thermal contact between Bi2Te3 and FeSi2 the junctions have to remain mechanically and chemically and chemically stable over long term. A Bi2Te3-SiO2 composite interlayer was used to adjust the different coefficient of thermal expansion (CTE) of FeSi2 (=7*10**-6 K**-1) and Bi2Te3 (=19*10**-6 K**-1). Due to low chemical stability of the Bi2Te3/FeSi2 contact at elevated temperatures (1000 h at 300 deg.C) a contacting material (diffusion barrier) based on Ni, Zn, Ti and ZnTe was tested. Some contacts show excellent chemical and mechanical stability, though the electrical properties of the contacts do not meet the requirements (e.g.ZnTe is a wide gap semiconductor with high electrical resistively). According to very recent studies at the Zn-based diffusion barriers a very thin layer of undoped ZnTe growing at the Bi2Te3/Zn interface causes the deterioration of the contact resistance. Ideas solving this problem are outlined and discussed. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 281-286 圧縮加工による木材の傾斜構造および熱伝導率の制御 Control of Grading Structure and Thermal Conductivity of Wood by Compressing Process Yoshihiro Obata, Kazutoshi Takeuchi, Kouichi Akaeda, Kozo Kanayama Yoshihiro Obata, Kazutoshi Takeuchi, Kouichi Akaeda, Kozo Kanayama  Compressed wood has different grading structure in an annual ring from one of natural wood. This paper treats the relationship between grading structures and effective thermal conductivity of natural and compressed woods. The Lorentz function and the power function are assumed as grading patterns of thermal conductivity. The grading thermal conductivity shows smaller effective thermal conductivity than the homogeneous wood with same average density. The sharper grading pattern gives much smaller effective thermal conductivity. The grading pattern of compressed wood is assumed as a model with locally compressed region. The calculated effective thermal conductivity by the model agrees with the measured thermal conductivity. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 287-292 大型NaX ゼオライト結晶形成のシーディング効果 Effects of Seeding on the Formation of Large NaX Zeolite Crystals Ik Jin Kim, Hae Jin Lee Ik Jin Kim, Hae Jin Lee  The problem with zeolite crystals synthesized by conventional methods is that they are extremely small: their size typically varies 2 and 8 micrometer, to better define the structure of a zeolite, scientists need to grow crystal that are 100 to 1000 times larger. In this work, large crystal zeolite NaX with a uniform size of 50 micrometer were grown by a continuous crystallization method from seed crystals (5-10 micrometer) formed in a mother solution with the 3.5Na2O:Al2O3:2.1SiO2:1000H2O composition. In order to grow zeolite NaX crystals to an appropriate size by the continuous method, the mother solution was fed into an autoclave a solution with various seed contents (3-20 wt%); the autoclave has at 90 deg.C and the solution was added after 7, 12, 16, 19 and 24 days or at 100deg.C after 7 and 9 days. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 293-298 NOxの減少を目的とした進行性積層により作製されたTiO2-カオリンFGMの機械的特性 Mechanical Properties of TiO2-Kaolin FGM Produced by Progressive Lamination Method for NOx Reduction Yoshihisa Uchida, Shuntaro Higa, Yoshiyuki Uchida, Niichi Hayashi Yoshihisa Uchida, Shuntaro Higa, Yoshiyuki Uchida, Niichi Hayashi  Mechanical properties of TiO2-kaolin Functionally Graded Materials (FGMs) that combined TiO2 and Korean kaolin (Al2Si2O5(OH)4) in a graded distribution were experimentally investigated. TiO2 is an excellent photocatalysis material, however, it does not have the mechanical strength sufficiently. Therefore, FGMs were used as the photocatalysis materials with mechanical strength. To improve the mechanical properties, Korean kaolin was selected as a binder. Bulk FGMs were produced by vacuum filtration and compression involving wet filtration, mechanical compression and sintering. By this process, it is easy to control the thickness of FGMs. The porosity in FGM depends on the content of TiO2. The porosity in FGM decreases with increasing pressure of the compressor. The shrinkage decreases with increasing compression pressure at all ratios of TiO2 and kaolin. The materials have almost no shrinkage at 10 MPa. The bending strength and the Young's modulus depends on content of TiO2. The bending strength of material was found to be approximately 2.5 MPa for 10 MPa compression pressure at TiO2 side. The bending strength and the Young's modulus increases with increasing compression pressure. These results indicate that kaolin particles are useful to improve the strength, etc., can be controlled by content of TiO2 and compression pressure. NO of 11.7 mg/m**2h was removed under present conditions. The sintering temperature ensured the optimal removal of NOx was 800deg.C. After NOx removal test, the FGMs were found to be free from erosion due to photocatalysis. And kaolin particles do not interfere in photocatalysis effect of TiO2. It can be concluded that TiO2-Kaolin FGM have a possibility for application to the air purification. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 299-304 ゼオライト結晶でコーティングしたセラミック泡 Ceramic Foams coated with Zeolite Crystals F.Snijkers, S.Mullens, A.Buekenhoudt, W.Vandermeulen and J.Luyten F.Snijkers, S.Mullens, A.Buekenhoudt, W.Vandermeulen and J.Luyten  Ceramic foams can be used as filters, dust collectors, lightweight components and catalyst carriers. They can be produced by a variety of techniques. The performance of ceramic foams will be strongly improved when their mechanical properties are improved. For this reason, we produced ceramic foams both by a modified reaction bonded (RB) replica technique and by gel casting. With both methods, reticulated foam structures with enhanced mechanical strength were obtained. Zeolites are a special type of materials that are characterized by high catalytic properties. They can be brought on a structured carrier by dip and slurry coating. Nevertheless, in situ coating has as main advantage that the support is used as the base for nucleation. This results in the formation of a chemical bond between the zeolite crystals and the support. The goal of this contribution is twofold: at first we demonstrate how Al2O3 foams with improved mechanical strength can be produced both by the modified RB-alumina replica technique and by gel casting. Secondly, it is shown that these ceramic foams can be coated with (silicalite) zeolite crystals by in-situ crystallization from a precursor sol. The two-layer material combinations have been characterized with FESEM, XRD, CT (computer assisted tomography), IA (Image Analysis) and by mechanical tests. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 305-310 均質コーティングおよびFGMコーティングの腐食耐性 Corrosion Resistance of Homogenous and FGM Coatings Marina Malinina, Tina Sammi, Michael Gasik Marina Malinina, Tina Sammi, Michael Gasik  Homogeneous and FGM environmental barrier coatings (EBC) made of alumina - NiCr on the steel substrates by high-velocity oxygen fuel (HVOF) spraying technique were studied. At room temperature, these coatings were characterized by DC polarization measurements and by electrochemical impedance spectroscopy (EIS) after various exposure times in highly aggressive basic solutions. At high temperatures (400-750 deg.C) corrosion resistance was tested in respect to sulfide - sulfate - chloride - carbonate melts in air, which simulates environments in incinerators, craft recovery boilers and turbines. After testing, the samples were examined by SEM and EDS and their corrosion resistance was compared. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 311-316 ソルゲル法により作製された高度排水処理用TiO2基膜 TiO2 based films prepared by sol-gel method for advanced water treatment A.Barau (Szatvanyi), M.Crisan, M.Gartner, V.Danciu, V.Cosoveanu, I.Marian, M.Anastasescu, Maria Zaharescu A.Barau (Szatvanyi), M.Crisan, M.Gartner, V.Danciu, V.Cosoveanu, I.Marian, M.Anastasescu, Maria Zaharescu  In the present work, iron doped TiO2 films were prepared by sol-gel method. An extensive study by varying the dopant quantity (0, 0.7, 1.4, 5 % wt Fe2O3 related to TiO2), the type of substrate (glass or ITO coated glass) and annealing temperature (300 and 500 deg.C) was performed. The sol-gel process evolution was studied by viscosity measurements and the unsupported gels were analyzed by thermal analysis (DTA/TGA) and IR spectroscopy. The deposited films were characterized by spectroellipsometry (SE). The catalytic activity of the films was determinate by measuring the degradation rate of the salicylic acid used as a model organic substance. A complex influence of the investigated parameters on the photocatalytic properties of the TiO2 based films was established. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 317-322 細胞膜としてのセラミックペーパー上へのNaX分子篩ゼオライト膜の合成および特性評価 Synthesis and characterization of NaX molecular sieve Zeolite films on ceramic paper for membranes Hae Jin Lee, Hyung Chul Kim, Ik Jin Kim Hae Jin Lee, Hyung Chul Kim, Ik Jin Kim  NaX molecular sieve films on ceramic paper prepared by in-situ hydrothermal method were investigated. The NaX zeolite seed crystals of a uniform size of 5 micrometer were synthesized by hydrothermal method in a mother solution having a composition of 3.5Na2O : Al2O3 : 2.1SiO2 : 500-1000H2O. These dip-coated NaX seed crystal on ceramic paper lead to further the thickness (20-100 micrometer) of NaX film on the substrate at 90 deg.C for longer 3-7 days in autoclave. Pure zeolite films consisting of a continuous intergrown of 5-20 micrometer NaX crystal have been prepared on the substrates. The zeolite films were characterized by XRD, SEM, BET and XRF. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 325-330 ソルゲルスピンコーティングプロセスによるインジウムー酸化スズ(ITO)薄膜の作製への焼鈍し条件の影響 Effects of annealing condition on the preparation of indium-tin oxide (ITO) thin films via sol-gel spin coating process Hyun-Woong Han, Young-Hoon Yun, Sung-Churl Choi Hyun-Woong Han, Young-Hoon Yun, Sung-Churl Choi  Indium tin oxide (ITO) thin films were deposited on glass substrates via sol-gel spin coating process from a mixed solution of Indium (III) acetylacetonate and Tin (IV) iso-propoxide. Then, ITO thin films were fired at 500 deg.C, and then annealed at 500 deg.C for 30 min with the sequential annealing process; Vacuum->N2->Ar/H2, N2->Ar/H2 and Ar/H2 gas. The effects of the different annealing processes on the surface morphologies and sheet resistance of ITO thin films were investigated. Sheet resistance values of ITO thin films treated under Vacuum->N2->Ar/H2, N2->Ar/H2 and Ar/H2 annealing process were 1.25 kohm/sq. 3.18 kohm/sq. and 4.92 kohm/sq., respectively. Actually, the sequential atmosphere gases and non-oxidizing gas, which were used in annealing process influenced the microstructural features or surface morphologies of ITO thin films: grain size and surface roughness. Thus, it was presumed that the sequential annealing condition influenced the densification behavior in the microstructural evolution of ITO thin films. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 331-334 ソルボサーマル加工によるインジウムー酸化スズナノ粉体の合成 The Synthesis of Indium Tin Oxide Nano-Powders by Solvothermal Process Jin-Seok Lee, Sung-Churl Choi Jin-Seok Lee, Sung-Churl Choi  Well-crystallized and nano-sized indium tin oxide (ITO) powders were prepared by a solvothermal process from a mixed solution consisting of indium nitrate and tin chloride. The characteristics of the solvothermally synthesized ITO powders were studied to investigate the contribution of the processing variables on the physic-chemical properties of powders. The results of this study show that the nano-sized blue ITO powders with a single phase could be directly obtained by changing the medium from water to organic solvent. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 335-340 室温ー400℃間でのAlN/CrN多層構造の圧痕 Indentation of AlN/CrN multilayers from room temperature to 400 deg.C. F.Giuliani, A.Goruppa, S.J.Lloyd, D.Teer, W.J.Clegg F.Giuliani, A.Goruppa, S.J.Lloyd, D.Teer, W.J.Clegg  Observations elsewhere have shown that multilayer structures with layers -10nm thick can be harder than monolithic ones. Here we see whether these effects can be observed at high temperatures and investigate the effect of temperature on the manner of deformation. The hardness of an AlN/CrN multilayer structure with a range of wavelengths from 6-200nm has been related to the deformation behavior observed by cross-sectional transmission electron microscopy and atomic force microscopy. These observations suggest that the mechanical properties of the coatings are dominated by the refinement in the columnar microstructure rather than directly by an effect of the layer interfaces on dislocation motion. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 341-346 超音速フリージェットPVDによるFGMコーティングにおけるナノ構造複合材の作製 Fabrication of nanostructure composites in functionally graded coatings with supersonic free-jet PVD Atsushi Yumoto, Takahisa Yamamoto, Fujio Hiroki, Ichiro Shiota, Naotake Niwa Atsushi Yumoto, Takahisa Yamamoto, Fujio Hiroki, Ichiro Shiota, Naotake Niwa  Graded Al/AlTi and Al/Al-Si coatings are prepared by depositing nanoparticles with supersonic free-jet PVD (SFJ-PVD). The SFJ-PVD has been developed as a new coating method in which a coating film is formed by depositing nanoparticles with very high velocity onto a substrate. The high velocity of nanoparticles is produced by the supersonic gas flow of inert gas. A smooth, compact and defect-free microstructure is formed both at the interface between substrates and coating films and inside the coating films. The microstructures of Al/AlTi and Al/Al-Si coating films have very fine grain size. Mixing Ti and Al nanoparticles by depositing them onto a substrate produces in-situ syntheses of gamma-TiAl and alpha2-Ti3Al intermetallic compounds on the substrate. It is confirmed with nano-indentation hardness tester that graded coatings have graded hardness corresponding to the gradation of composition. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 347-352 PVDおよびCVDによるC/C機能傾斜コーティング Functionally graded coatings of carbon reinforced carbon by physical and chemical vapour deposition (PVD and CVD) K.Maile, K.Berreth, A.Lyutovich K.Maile, K.Berreth, A.Lyutovich  This paper reflects our R & D results in the field of functionally graded coating processes. For industrial applications a special architecture for coatings is necessary: because the surface has to withstand environmental attacks, specific physical and mechanical functions and characteristics are required. In the interface region to the substrate additional stresses and strains occur due to the different materials combined. Consequently, the coatings have to be chemically and mechanically adjusted to the substrates. For this challenging problem, a concept named Materials Adapter has been developed within the frame of different research programs at MPA. For optimization of the interface region an ion bombardment-activated inter-diffusion process was employed by using ion assisted electron beam PVD (IA EB PVD). Several Cr, Ti, Al and Zr coatings have been produced. An automated precursor inlet has been installed for CVD processes to obtain preset composition profiles for graded systems. Especially multilayer stacks of PyC-SixCy-SiC-Si3N4-Al2O3 have been deposited in a single growth process. The structure and composition of the coatings and interfaces were investigated by XRD, AFM, SEM, EDX, EPMA, ESCA and the micro-Raman spectroscopy. The characterization confirms the gradual transition between Si and Cr, as well as between Cr and Al deposited by IA EB PVD and between C and Si grown by CVD. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 353-358 Ti-6%Al-4%V合金および陰極アーク法でコーティングされた超合金の相互作用 Interaction between Ti-6%Al4%V alloys and hardmetals coated by cathodic-arc technology C.M.Moreno, G.Artola, J.M.Sanchez C.M.Moreno, G.Artola, J.M.Sanchez  At present, milling of titanium based alloys for aerospace applications is mainly carried out with un-coated WC-Co carbide tools. The present work evaluates the chemical interaction of the Ti-6%Al-4%V alloy with these WC-Co commercial hardmetals. Strong decarburation induced by carbon diffusion to the Ti based alloy is observed at temperatures ranging from 750-1000deg.C. This reaction is responsible for the high adhesion found at the alloy-carbide interface. Different cathodic arc coatings have proved efficient in inhibiting such reaction and the associated adhesion to the Ti-6%Al-4%V alloy. Delamination induced by reaction between the Ti6Al4V alloy and AlTiN and TiAlCN coatings increases with the hot pressing temperature, being more severe for the AlTiN material. A lower bound of 44 J/m**2 has been obtained for the interfacial fracture energy of cathodic arc PVD TiAlCN coatings on hardmetal substrates, this value being significantly higher than those previously reported for TiAlN materials. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 359-364 ESAおよびTRESS法を用いて作製された新しい多機能FGMコーティング New Multifunctional FGM coatings produced using ESA and TRESS methods A.E.Kudryashov, E.I.Zamulaeva, P.V.Vakaev, Yu.S.Pogozhev, E.A.Levashov A.E.Kudryashov, E.I.Zamulaeva, P.V.Vakaev, Yu.S.Pogozhev, E.A.Levashov  The influence of nanodispersed complex additives (ZrO2, Al2O3, W, WC, WC-Co, NbC, Si3N4) to SHS electrode materials on the mass transfer, structure and properties of electrospark coatings has been considered depandent on variation of the energy regimes of processing. The influence of the pulse discharge energy on the structure, composition, and properties of TRESS coatings has been studied. The optimum energy regimes of depositing high-quality multifunctional graded ESA and TRESS coatings have been found. It has been shown that introduction of nanodispersed complexes into electrode materials promotes improvement of the properties of ESA coatings. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 367-372 傾斜機能材料における3D亀裂問題のための簡略化Galerkin境界要素法 A simple Galerkin boundary element method for three-dimensional crack problems in functionally graded materials Glaucio H Paulino, Alok Sutradhar Glaucio H Paulino, Alok Sutradhar  This paper presents a Galerkin boundary element method for solving crack problems governed by potential theory in nonhomogeneous media. In the simple boundary element method, the nonhomogeneous problem is reduced to a homogeneous problem using variable transformation. Cracks in heat conduction problem in functionally graded materials are investigated. The thermal conductivity varies parabolically in one or more coordinates. A three dimensional boundary element implementation using the Galerkin approach is presented. A numerical example demonstrates the efficiency of the method. The result of the test example is in agreement with finite element simulation results. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 373-378 FGMコーティングの3D破壊解析 Three dimensional fracture analysis of FGM coatings Ozgur Inan, Serkan Dag, Fazil Erdogan Ozgur Inan, Serkan Dag, Fazil Erdogan  In this study the three-dimensional surface cracking of a graded coating bonded to a homogeneous substrate is considered. The main objective is to model the subcritical crack growth process in the coated medium under a cyclic mechanical or thermal loading. Because of symmetry, along the crack front conditions of mode I fracture and plane strain deformations are assumed to be satisfied. Thus, at a given location on the crack front the crack propagation rate would be a function of the mode I stress intensity factor. A three-dimensional finite element technique  for nonhomogeneous elastic solids is used to solve the  problem and the dimensional finite element technique for nonhomogeneous elastic solids is used to solve the problem and the displacement correlation technique is used to calculate the stress intensity factor. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 379-384 熱衝撃下での傾斜機能熱遮蔽コーティングの時間依存挙動および破壊 Time-dependent behavior and fracture of functionally graded thermal barrier coatings under thermal shock Klod Kokini, Sudarshan V.Rangaraj Klod Kokini, Sudarshan V.Rangaraj  The thermal fracture and its dependence on time-dependent behavior in functionally graded yttria stabilized zirconia-NiCoCrAlY bond coat alloy thermal barrier coatings was studied. The response of three coating architectures of similar thermal resistance to laser thermal shock tests was considered, experimentally and computationally. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 385-390 界面亀裂を持つ傾斜機能熱遮蔽コーティングの計算ミクロ工学法による破壊解析 Fracture Analysis of Functionally Graded Thermal Barrier Coating with Interface Crack by Computational Micromechanics Method Shu-Yong Yang, Li-Sheng Liu, Qing-Jie Zhang Shu-Yong Yang, Li-Sheng Liu, Qing-Jie Zhang  The fracture of the functionally graded thermal barrier coating (TBC) under the thermal loads is a key for the engineering application of this kind of materials. In the previous studies, the functionally graded TBC is usually simplified into a laminate by homogenizing the material of each interlayer as an isotropic layer. Nevertheless, this method is a macro equivalent method, which neglected the micromechanics method (CMM) is employed to study the fracture problem of the functionally graded TBC with the interface crack. Essentially, CMM is a finite element method. Firstly, the microstructure photos of the functionally graded TBC are required. Secondly, the digital image processing technique, the auto mesh generation techniques are used to construct the finite element model. Finally, the finite element method is utilized for the fracture analysis of the functionally graded TBC under the thermal shock loads. Moreover, the problem is also analyzed using the macro equivalent method and the results from the two methods are compared.The temperature field obtained using CMM is basically consistent with the one obtained from the macro equivalent method and the influences of the interface crack on the temperature fields are limited in a local region. But results of the driving forces for the crack propagation, J-integrals, from the two methods are quite different. Comparing with the CMM results, J-integrals from the macro equivalent method are smaller. It means that the macro equivalent method tends to underestimate the driving force of the interface crack. On the other hand, the prediction of the critical location of the interface crack from the two methods is also different. Since the influence of the microstructure is taken into account by CMM, results of the present work may suggest that CMM is a more useful and accuracy method for the fracture analysis of the functionally graded TBC. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 391-396 傾斜機能複合材料の弾性変形に関するマルチスケール構造 A multiscale framework for elastic deformation of functionally graded composites H.M.Yin, L.Z.Sun, G.H.Paulino H.M.Yin, L.Z.Sun, G.H.Paulino  A micromechanics-based elastic model is developed for two-phase functionally graded composites with locally pair-wise particle interactions. In the gradation direction, there exist two microstructurally distinct zones: particle-matrix zone and transition zone. In the particle-matrix zone, the homogenized elastic fields are obtained by integrating the pair-wise interactions from all other particles over the representative volume element. In the transition zone, a transition function is constructed to make the homogenized elastic fields continuous and differentiable in the gradation direction. The averaged elastic fields are solved for transverse shear loading and uniaxial loading in the gradation direction. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 397-402 非均質コーティングシステムにおける埋め込み亀裂および界面亀裂の相互作用 Interaction between an embedded crack and an interface crack in nonhomogeneous coating system E.E.Theotokoglou, G.H.Paulino E.E.Theotokoglou, G.H.Paulino  A general methodology is constructed for the fundamental solution of a crack in the homogeneous half-plane interacting with a crack at the interface between the homogeneous elastic half-plane and the nonhomogeneous elastic coating in which the shear modulus varies exponentially with one coordinate. The problem is solved under plane strain or generalized plane stress condition using the Fourier integral transform method. The stress field in the homogeneous half plane is evaluated by the superposition of two states of stresses, one is associated with a local coordinate system in the infinite fractured plate, while the other in the infinite half plane defined in a structural coordinate system. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 403-408 傾斜機能材料における応力拡大係数およびT-応力の正確な数値評価 On accurate numerical evaluation of stress intensity factors and T-stress in functionally graded materials Jeong-Ho Kim, Glaucio H. Paulino Jeong-Ho Kim, Glaucio H. Paulino  This paper revisits the interaction integral method to evaluate both the mixed-mode stress intensity factors and the T-stress in functionally graded materials under mechanical loading. A non-equilibrium formulation is developed in an equivalent domain integral form, which is naturally suitable to the finite element method. Graded material properties are integrated into the element stiffness matrix using the generalized isoparametric formulation. The type of material gradation considered includes continuum functions, such as an exponential function, but the present formulation can be readily extended to micromechanical models. This paper presents a fracture problem with an inclined center crack in a plate and assesses the accuracy of the present method compared with available semi-analytical solutions. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 409-414 傾斜機能材料における混合モード亀裂伝播 Mixed-Mode Crack Propagation in Functionally Graded Materials Jeong-Ho Kim and Glaucio H. Paulino Jeong-Ho Kim and Glaucio H. Paulino  This paper presents numerical simulation of mixed-mode crack propagation in functionally graded materials by means of a remeshing algorithm in conjunction with the finite element method. Each step of crack growth simulation consists of the calculation with the finite element method. Each step of crack growth simulation consists of the calculation of the mixed-mode stress intensity factors by means of a non-equilibrium formulation of the interaction integral method, determination of the crack growth direction based on a specific fracture criterion, and local automatic remeshing along the crack path. A specific fracture criterion is tailored for FGMs based on the assumption of local homogenization of asymptotic crack-tip fields in FGMs. The present approach uses a user-defined crack increment at the beginning of the simulation. Crack trajectories obtained by the present numerical simulation are compared with available experimental results. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 415-420 機械加工FGM：残留応力の再分配 Machining FGM: Residual Stresses Redistribution Baosheng Zhang, Michael Gasik Baosheng Zhang, Michael Gasik  The effect of gradient composition profiles and FGM geometry is studied for the case of machining (grinding) for disk shaped specimens of alumina-based ceramics. Results of FEM simulation and experiment show that stresses redistribution in FGM disks may be significant and non-uniform, but with a proper approach a compromise solution might be found to obtain desired properties level of FGM in the final state. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 421-428 典型的なFGMの微小応力の有限要素シミュレーション：ソフトトライボ合金の場合 Finite Element Simulation of Microstresses in a Traditional FGM: The Case of Soft Tribo-Alloys Rafael Schouwenaars, Victor H. Jacobo, Sara Cerrud and Armand Ortiz Rafael Schouwenaars, Victor H. Jacobo, Sara Cerrud and Armand Ortiz  Journal bearings are graded systems with a metal-metal composite as the functional layer. Estimation of the microscale stress distributions is used to analyze the interaction between microstructure, material properties and damage mechanisms during wear. The analysis is executed by means of simple plane-strain finite element models mimicking experimentally observed microstructures. It is found that under realistic macrostress conditions no tensile microstresses are induced in the triboalloy and that plastic flow is inhibited by the graded structure. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 429-434 均質傾斜コーティングRLVスラストセルライナーの熱機械解析 Thermo-Mechanical Analysis of RLV Thrust Cell Liners with Homogeneous and Graded Coatings Daniel T. Butler,Jr., Marek-Jerzy Pindera, and Jacob Aboudi Daniel T. Butler,Jr., Marek-Jerzy Pindera, and Jacob Aboudi  The Higher-Order Theory for Cylindrical Functionally Graded Materials is employed to investigate the effectiveness of thermal barrier coatings in mitigating deformation mechanisms in thrust cell liners leading to experimentally observed failure modes. The results indicate that under the employed thermo-mechanical loading histories coating thickness has a great impact on temperature and deformation fields within the cooling channel wall of a thrust cell liner, with thicker coatings producing more desirable temperature and deformation fields. Functional grading of metallic substrate and coating materials does not produce improvement in terms of overall thrust cell liner performance. Further, the application of grading is potentially detrimental due to likely roughening of the thrust cell liner wall in the combustion chamber as a result of local deformations around relatively coarse inclusions. The homogenized approach to analyzing the graded coating effectiveness is incapable of capturing these localized effects, leading to erroneous conclusions. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 435-440 トポロジー最適化による傾斜機能構造設計 Design of Functionally Graded Structures Using Topology Optimization Glaucio H.Paulino and Emilio Carlos Nelli Silva Glaucio H.Paulino and Emilio Carlos Nelli Silva  The concept of functionally graded materials (FGMs) is closely related to the concept of topology optimization, which consists in a design method that seeks a continuum material distribution in a design domain. Thus, in this work, topology optimization is applied to design FGM structures considering a minimum compliance criterion. The present approach applies the so-called "continuous topology optimization" formulation where a continuous change of material properties is considered inside the design domain by using the graded finite element concept. A new design is obtained where distribution of the graded material itself is considered in the design domain, and the material properties change in a certain direction according to a specified variation, leading to a structure with asymmetric stiffness properties. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 441-446 マイクロ遺伝アルゴリズムによる安定した熱フラックス負荷のもとでのFGMコーティングの材料組成の最適化 Optimization of Material Composition of FGM Coating under Steady Heat Flux Loading by Micro-Genetic Algorithms Jian-Ping Wang, Gang Chen and Peng-Cheng Zhai Jian-Ping Wang, Gang Chen and Peng-Cheng Zhai  This paper studies the optimization problem of composition distribution of functionally graded material (FGM) coating subjected to steady heat flux loading. The investigation object of the paper is an infinite plate substrate with FGM coating in the surface. The materials are heated at the ceramic surface (upside) with a steady high-intensity heat flux input, and cooled at the metal surface (underside) with flowing liquid nitrogen. The thermal stress distribution and the temperature distribution are obtained by formulation. For optimization, the design variables are the thickness of each interlayer and the volume fraction distribution of the coating. The objective function is the danger coefficient. In the paper, three different optimization schemes are considered and compared. The micro GA and related parameters are discussed in detail. Optimizing the thermal stress distribution and minimizing the danger coefficient are carried out by micro GA. The optimization results of composition distribution are gained, and the results show the optimum composition distribution can distinctly reduce the danger coefficient. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 447-452 固有融着帯モデル傾斜機能複合材の動的破壊 Dynamic Fracture of Functionally Graded Composites Using an Intrinsic Cohesive Zone Model Glaucio H.Paulino and Zhengyu Zhang Glaucio H.Paulino and Zhengyu Zhang  This paper presents a Cohesive Zone Model (CZM) approach for investigating dynamic failure processes in homogeneous and Functionally Graded Materials (FGMs). The failure criterion is incorporated in the CZM using both a finite cohesive strength and work to fracture in the material description. A novel CZM for FGMs is explored and incorporated into a finite element framework. The material gradation is approximated at the element level using a graded element formulation. A numerical example is provided to demonstrate the efficacy of the CZM approach, in which the influence of the material gradation on the crack branching pattern is studied. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 453-458 FGMの弾性波の伝播特性の最適化 The Optimization of Propagation Characteristic of Elastic Wave in FGM Li-Sheng Liu, Qing-Jie Zhang and Peng-Cheng Zhai Li-Sheng Liu, Qing-Jie Zhang and Peng-Cheng Zhai  The reflected coefficient of functionally graded layer to waves is very important as the design of impact-resistant FGMs. In the paper, the optimization problem of propagation characteristic of elastic wave in FGM has been investigated. The relation between the top layer's stress and displacement and the bottom layer's is deduced from elastic propagation equation as the incident wave is a plane and harmonic elastic stress wave, then the reflected coefficient of gradient layer is obtained, and the reflected coefficient is selected as object function of optimization. The thickness of each layer is selected as optimization design parameter. The conjugate gradient method is used to get the optimal results about gradient layers' thickness. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 459-464 アルミナ／エポキシ混合物から誘電率傾斜FGMを作製するための遠心力法の数値シミュレーション Numerical Simulation of a Centrifugal Process to Fabricate Permittivity Graded FGM from Alumina/Epoxy Mixture Shin-ichiro Tsuru, Noriyuki Hayashi, Tomohiko Onoda, Yasushi Sakamoto, Masanori Hara Shin-ichiro Tsuru, Noriyuki Hayashi, Tomohiko Onoda, Yasushi Sakamoto, Masanori Hara  A new numerical method to simulate the centrifugal process of fabricating functionally graded materials (FGMs) from solid-particles/viscous-matrix mixtures is proposed, and the simulation method was successfully applied to a practical fabrication process of FGM from an alumina-fillers/epoxy-resin mixture. Gradient profiles of dielectric constant of the resultant FGM were estimated by using the proposed method and compared with the experimental ones, resulting in reasonable agreement between them. Based on the numerical results, gradient profiles of the number density and size of the dispersed fillers were confirmed, and contribution of the filler size toward the gradient in the packing fraction was demonstrated. It is concluded that the gradient in the filler distribution can be intentionally regulated by changing not only the centrifugal conditions, but also the size distribution of the fillers. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 465-470 セラミック基材のレーザー誘発による修正過程の数値シミュレーション Numerical Simulation of Laser Induced Modification Processes of Ceramic Substrates M.Rohde, O.Baldus, D.Dimitrova, S.Schreck M.Rohde, O.Baldus, D.Dimitrova, S.Schreck  Laser supported processes can be used to modify the electrical and thermal properties of ceramic substrates locally. These processes are characterized by a strong thermal interaction between the laser beam and the ceramic surface which leads to localized melting. During the dynamic melting process an additive material is injected into the melt pool in order to modify the physical properties. The heat and mass transfer during this dynamic melting and solidification process has been studied numerically in order to identify the dominant process parameters. Simulation tools based on a finite volume method have been developed to describe the heat transfer, fluid flow and the phase change during the melting and solidification process has been studied numerically in order to identify the dominant process parameters. Simulation tools based on a finite volume method have been developed to describe the heat transfer, fluid flow and the phase change during the melting and solidification of the ceramic. The results of the calculation have been validated against experimental results. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 471-476 共沈降によるFGM作製に関する設計・予測モデル Design Model and Prediction Model on Preparation of Functionally Graded Material by Co-Sedimentation Zhiguang Zhou, Lianmeng Zhang, Qiang Shen, Daoren Gong Zhiguang Zhou, Lianmeng Zhang, Qiang Shen, Daoren Gong  From the process of sedimentation the mathematical relationship between deposition volume and powder properties as well as sedimentation parameters was deduced in this paper. The relationship was expressed by using indirect method. Based on the formula, design model and prediction model were set up. The models can be used to design powder properties and predict the volume fraction of FGM. Programs to solve the models were developed in numerical methods. As examples, TiC-Ni system FGM were designed and predicted. The prediction results fit well with the design. Experiment of Mo-Ti system FGM was used to validate the prediction model. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 477-482 焼結処理時の傾斜構造粉体コンパクトの応力解析 Stress Analysis of Powder Compacts with Graded Structures in Sintering Process Kazunari Shinagawa, Yasushi Hirashima Kazunari Shinagawa, Yasushi Hirashima  During sintering of metal/ceramic functionally graded materials, crack are often formed on the surface on the top ceramic layer due to the internal stress are examined by using the finite element method as well as the plate theory for sintering. Uniaxial pressing, which gives the counter moment against the warping, can decrease the bending stress but only in the middle of the surface. Thinning the top layer is found to be effective in reducing the tensile stress on the surface when the sintering properties of some layers are modified appropriately. The suppression of the surface cracking in the improved graded powder compacts is confirmed by experiment. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 483-488 コンピュータ統合による人工股関節プロテーゼ用FGM構成材の安全設計 Computer-Integrated safe Design of FGM Component for Hip Replacement Prosthesis B.Zhang, M.Gasik, A.Facchini, M.Pressacco, P.Dallapria, S.Posocco B.Zhang, M.Gasik, A.Facchini, M.Pressacco, P.Dallapria, S.Posocco  Computer-integrated safe design of FGM component for hip replacement prosthesis was presented based on principle of optimal stresses distribution in the FGM component. The goals were to create an FGM structure with reasonable compressive stresses on the surfaces (subjected to wear) and to keep them during the entire manufacturing cycle (sintering, machining, assembling and application). The residual stresses developed in the different parts of the composite were implemented into the subsequent process of the surface grinding and assembly to simulate properly the whole processing route to ensure optimal combination of the processing parameters. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 489-493 傾斜材料の3D熱伝導に関する最適設計 Optimal design of graded materials in 3-D heat transfer Alberto Donoso Alberto Donoso  We explore the following optimal design problem in 3-D heat transfer: given fixed amounts of two isotropic conducting materials, decide how we are to mix them in a three-dimensional domain so as to optimize a certain cost functional depending on the underlying temperature gradient. By relying on a suitable reformulation of the problem, and examining its relaxation, easier relaxations for the design problem are obtained in most cases. We provide numerical evidence, based on optimality conditions for the new relaxations, that Tartar's result is verified when the target field is zero (also for divergence-free fields) and that optimal solutions can be interpreted as graded materials. In such cases, they are given by first-order laminates somewhat specials. This same evidence also holds for a general quadratic functional in the fields and as a particular case, for the compliance one. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 495-500 セラミック／金属機能傾斜耐熱コーティングのクリープ応答 Creep Response of Ceramic/Metal Functionally Graded Thermal Barrier Coating Jian-Ping Wang, Shu-Yong and Li-Sheng Liu Jian-Ping Wang, Shu-Yong and Li-Sheng Liu  The functionally graded thermal barrier coating (TBC) serves in high temperature and/or high temperature gradient environment for a long time. According to the experimental and theoretical research, in the metal substrate and the metal-rich interlayer creep deformation will appear under high temperature environment. In order to design and optimize the compositional distribution of FGM, it is necessary to analyze the stress and strain response taking into account the creep phenomenon of the materials.In this article, the thermo-mechanical responses of ceramic/metal functionally graded TBC in work environment are analyzed by a finite element method. The creep phenomenon of the metal and the interlayer are taken into account. The numerical results indicate that the creep behavior of all interlayer, even for ceramic-rich interlayer, cannot be neglected in analysis. It is suggested that the creep phenomenon of the material is important in the functionally graded TBC systems. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 501-506 不均一分散アルミナ充填剤を用いた遠心力法による誘電率傾斜エポキシ樹脂の作製 Fabrication of Permittivity Graded Epoxy Resin with Non-Uniform Dispersion of Alumina Fillers by a Centrifugal Procedure Noriyuki Hayashi, Tomohiko Onoda, Yasushi Sakamoto, Shin-ichiro Tsuru, Toshinori Kawabe, Masanori Hara Noriyuki Hayashi, Tomohiko Onoda, Yasushi Sakamoto, Shin-ichiro Tsuru, Toshinori Kawabe, Masanori Hara  The centrifugal method was successfully applied to fabricate functionally graded materials with different profiles of gradient in permittivity from an alumina/epoxy mixture. Gradient of the number density, packing fraction, and size of the dispersed alumina fillers was confirmed. Non-spherical and spherical alumina fillers were employed to fabricate from each other. The gradient of filler dispersion was intentionally regulated by changing not only conditions of the centrifugal process, but also the size distribution and shape of fillers. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 507-516 セグメント化ペルチェ冷却の連続および不連続濃度関数でのモデル化 Modeling of Segmented peltier Cooling with Discrete and Continuous Concentration Function S.Walczak, W.Seifert, E.Muller S.Walczak, W.Seifert, E.Muller  Commercialization of Peltier coolers has progressed during last years and special efforts have been undertaken to enhance the efficiency of thermoelectric (TE) devices. Along with the continued search for advanced TE materials, the concept of FGM offers a strategy of gradual improvement of device performance. In reality a functional gradient in a TE material means a related spatial variation of all TE properties-Seebeck coefficient, electrical, and thermal conductivity-whereas the most relevant effect is linked to the gradient of the Seebeck coefficient. Due to the spatial dependence of the Seebeck coefficient, Peltier heat is absorbed or released inside the TE element under current flow (distributed Peltier effect) which can be exploited to shape the internal temperature profile in a desired manner.Starting from the first principles of thermoelectricity, a differential equation governing the coupling of thermal and electrical transport is derived within the frame of a one-dimensional model. It is shown that this approach can be also used to model multi-segment Peltier cooling devices. Temperature profiles T(x) have been calculated for a segmented TE element within the framework of a constant parameters theory.The work presents an analytical model for performance evaluation of multiply-segmented Peltier elements. Based on realistic material data exemplary calculations are presented for stacked and continuously graded elements. The problem is treated in a one-dimensional approach for a p-type stack containing N segments of different properties. Assuming constant TE material properties in each of the segments, the differential equation of TE transports has been solved to obtain the temperature profile T(x) in each segment. With the material properties values in each segment representing volume average values this model gives an excellent approximation also for continuously graded elements. The boundary conditions of the TE problem set-up, as conservation of heat at any intermediate junction between the segments, and fixed temperature at the cold and hot end of the element, lead to a linear equation system, which can be easily solved by means of standard methods. From the solution, all desired performance parameters can be deduced.Based on realistic material data exemplary calculations are presented for stacked and continuously graded elements. To demonstrate the developed numerical algorithm, gradients of the Seebeck coefficient are mainly considered. Calculations have been performed for N=2, 5, 10 and continuous gradients. As target parameters, the C.O.P. and the cooling power have been calculated as functions of the electric current. As well, the minimum temperature of the cold side has been determined for various shape of the Seebeck gradient. It is shown that the TE FGM effect can be almost completely utilized already by a stack of two to five homogeneous segments. The results allow for giving an estimation on the order of magnitude of performance improvement of both discontinuously and continuously graded Peltier cooling devices.The model calculation was implemented with the software tool Mathematica. The code provides an easy to handle convenient instrument for performance estimation of non-homogeneous Peltier pellets. Technological studies for controlled fabrication of those pellets are underway. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 517-522 傾斜機能層の粘性ー塑性波の伝播特性 The Propagation Characteristic of Viscous-Plastic Wave In Functionally Graded Layer Li-Sheng Liu, Qing-Jie Zhang, Peng-Cheng Zhai, Chang-Chu Zhu Li-Sheng Liu, Qing-Jie Zhang, Peng-Cheng Zhai, Chang-Chu Zhu  In the paper, propagation of two-dimensional viscous-plastic waves in graded layer media is investigated by numerical method. Firstly, an infinite model is used to analysis wave's propagation in FGMs, this model has a finite gradient layer and non-reflecting boundary condition is used to simplify the model to be finite. Then the characteristic of viscous-plastic wave's propagation in graded media is investigated on the base of this model. The following contents is researched by this model: (1) The refracted effect of functionally gradient layers on incident wave; (2) the effect of incident angle on the bottom layey's stress; (3) the effect of gradient layey's thickness on the bottom layey's stress. Finally, some interesting, reasonable  and important results are obtained by our researching work. English Functionally Graded Materials VIII (FGM 2004) Functionally Graded Materials VIII(FGM 2004) 28 2004-07-14 523-528 Co-V8C7合金の熱力学および微細構造 Thermodynamics and Microstructure of Co-V8C7 Alloy Shuigen Huang, Lin Li, Jef Vleugels, Omer Van der Biest Shuigen Huang, Lin Li, Jef Vleugels, Omer Van der Biest  The thermodynamic properties of the Co-V-C and Co-V8C7 systems are of interest for superfine cemented carbide applications. The model parameters for the Gibbs energy of the individual phases have been evaluated using the CALPHAD method by combining the recently optimized phase diagram information of the V-C, Co-C and Co-V system. The isothermal section of ternary system Co-V-C at 1400 deg.C and 1600 deg.C, as well as the vertical section of Co-V8C7 system were extrapolated. The calculated results, especially the liquid forming temperature of Co-V8C7 system was validated with experiments by using differential scanning calorimetry (DSC) analysis. Through controlling the carbon activity, various vertical sections with different carbon activity in Co-V8C7 system are presented. English