巻号一覧
63 巻, 4 号
April
選択された号の論文の15件中1～15を表示しています
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研究論文
研究論文
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楠瀬 智博, 西山 勝廣, 田中 公美子, 須川 修身2016 年 63 巻 4 号 p. 145-149
発行日: 2016/04/15
公開日: 2016/05/07
ジャーナル オープンアクセスThe powder metallurgy method was applied to prepare the particle-dispersed composite material with the addition of B in Mg-Al. The effects of manufacturing conditions on the structures and mechanical properties of the sintered compacts were investigated to find high strength and high functionality as an alloy. The sample composition of (Mg-9 %Al)-6.8 %B was produced by hot pressing and pressureless resintering. The powder was mechanical alloyed. Sintering temperature of 475 °C was adopted for the hot press, and with the sintering temperature controlled 600~800 °C. The new composite material has following appearances and performances; (1) High strength was exerted by addition of B as reinforcing particles. (2) Mechanical alloyed (Mg-9 %Al)-6.8 %B by hot-pressed at 475 °C followed by resintered at 770 °C, showed the bending strength of 621 MPa and the Rockwell hardness of 116 HRH.抄録全体を表示PDF形式でダウンロード (980K) -
今井 久志, 陳 冠宇, 近藤 勝義, 梅田 純子, 蔡 宏營2016 年 63 巻 4 号 p. 150-156
発行日: 2016/04/15
公開日: 2016/05/07
ジャーナル オープンアクセスIn this research, the effect of alloying elemental on the mechanical and electrical properties of powder metallurgy (PM) copper composite alloy with vapor-grown carbon fibers (VGCFs) was investigated. The alloying elements were titanium and silicon, which easily formed their carbides at elevated temperature. The Cu-Ti composites with VGCFs showed a slightly decreased yield stress compared to the monolithic Cu-Ti alloys. The electrical conductivity of the composite materials increased with increasing VGCFs content. However, the Cu-Si composites with VGCFs had mechanical and electrical properties which were the same as its monolithic alloy. Ti soluted in the matrix reacted with VGCFs, and resulted in a decrease of the solid solution element in the matrix according SEM and TEM observation. In the case of the Cu-Si composite, however, the reaction between VGCFs and solute Si elements to form Si-C compounds was never detected. The strength and conductivity of the Cu-Si with the VGCF composites were not improved.抄録全体を表示PDF形式でダウンロード (1520K) -
和田 任弘, 森合 勇介, 田中 宏明2015 年 63 巻 4 号 p. 157-165
発行日: 2015/04/15
公開日: 2016/05/07
ジャーナル オープンアクセスThe tool life in cutting high-nickel alloy is shorter than that in turning of carbon steel. In order to identify an effective tool material for the cutting of high-nickel alloy, the chip configurations, the tool wear and the surface roughness were experimentally investigated. The high-nickel alloy was turned with high-pressure coolant supplied. The results are as follows: (1) In turning with high-pressure coolant supplied, the effectiveness of chip breaking performance was improved. In this case, the chip length was shorter with the increase of the coolant pressure. (2) In the case of finish cutting high-nickel alloy, in the dry cutting large notch wear on the depth of the cut line was observed. In wet cutting with the cBN content of 60 % to 65 % under high cutting speed and high-pressure coolant supplied, it was possible to suppress the large notch wear. (3) In the high-pressure coolant cutting method of high-nickel alloy with a sintered cubic boron nitride compact tool, the cBN content of 60 % and the main element of the binder phase of Al2O3-Al was an effective tool material. (4) In the high-pressure coolant cutting method of high-nickel alloy with the cBN content of 60 % and the main element of the binder phase of Al2O3-Al, if the cutting coolant pressure is high and the cutting speed is low, large tool damage occurs to the notch boundary of the flank, and the tool life is short.
In conclusion, the tool life of the cBN content of 60 % and the main element of the binder phase of Al2O3-Al can be improved by increasing coolant pressure in turning high-nickel alloy with a sintered cubic boron nitride compact tool under high cutting speed.抄録全体を表示PDF形式でダウンロード (1433K) -
江川 大基, 久保田 正広2016 年 63 巻 4 号 p. 166-171
発行日: 2016/04/15
公開日: 2016/05/07
ジャーナル オープンアクセスRapidly solidified powders of Al-10 mass% Mg based alloys with or without additions of 1, 5 or 10 mass% Si were produced by atomizing and subsequent splat quenching on a water-cooled copper roll. Consolidation of the powders was done by cold pressing, vacuum degassing and hot extrusion (P/M materials). The microstructures of as-extruded P/M materials contained fine scale of intermetallic compounds. The size of the compounds in the Al-10Mg-1Si alloy was finer than that in the other alloys. The alloys containing excess Mg to the Mg2Si composition showed higher hardness and tensile strength than those containing excess Si to the Mg2Si composition at room temperature. Al-10Mg-1Si and Al-10Mg-10Si P/M materials showed the highest tensile strength of 480 MPa at room temperature and 140 MPa at 573 K, respectively.抄録全体を表示PDF形式でダウンロード (1036K) -
Raquel ORO, Elena BERNARDO, Mónica CAMPOS, Christian GIERL-MAYER, Herb ...2016 年 63 巻 4 号 p. 172-184
発行日: 2016/04/15
公開日: 2016/05/07
ジャーナル オープンアクセスIntroducing alloying elements through Master Alloy (MA) additions provides the unique opportunity of designing their composition to enhance sintering by forming a liquid phase. However, working with liquid phases poses important challenges like maintaining a proper dimensional control and minimizing the effect of secondary porosity on the final performance of the steel.
The critical parameters for designing low melting point compositions are analyzed in this work by combining the use of thermodynamic software tools, wetting angle/infiltration experiments, and advanced thermal analysis techniques. Due to their low ability to dissolve iron, Cu-based liquids present remarkable infiltration properties that provide homogeneous distribution of the alloying elements. Dissolutive liquids, on the other hand, tend to render more heterogeneous microstructures, rapidly solidifying in contact with the matrix. As a consequence of their lower infiltration capacity, dimensional changes upon liquid formation are significantly lowered. When using master alloys with high content in oxidation-sensitive alloying elements, the differences in oxygen affinity cause an oxygen transfer from the surface of the iron base particles to the surface of the master alloys. The change in the surface chemistry modifies the wetting capability of the liquid, and the dimensional stability becomes increasingly sensitive to the processing atmosphere.抄録全体を表示PDF形式でダウンロード (1789K) -
山本 裕一, 節 晃彦, 楠瀬 尚史, 品川 一成, 馮 旗2016 年 63 巻 4 号 p. 185-191
発行日: 2016/04/15
公開日: 2016/05/07
ジャーナル オープンアクセスThe layered titanates with lepidocrocite-like structure are expected as functional materials and also as precursors for soft chemical synthesis because of their excellent ion exchange and intercalation properties. In this study, we tried to hydrothermally synthesize the lepidocrocite-like K0.8Li0.27Ti1.73O4, and control their particle morphologies. The plate-like K0.8Li0.27Ti1.73O4 particles were synthesized by hydrothermal treatment of TiO2 in KOH-LiOH solutions. The formation of K0.8Li0.27Ti1.73O4 phase and its particle morphology were dependent on the concentrations of KOH and LiOH, reaction temperature, particle size and crystal phase of TiO2 starting material. Rutile phase showed a lower reactivity and gave larger particle size of K0.8Li0.27Ti1.73O4, than anatase phase. The particle size of K0.8Li0.27Ti1.73O4 product increased with increasing particle size of TiO2 starting material. The synthesized plate-like K0.8Li0.27Ti1.73O4 particles can be used as the precursor for the synthesis of plate-like BaTiO3 particles by solvothermal reaction.抄録全体を表示PDF形式でダウンロード (1049K) -
伊達 賢治, 石澤 俊崇, 関口 謙一郎2016 年 63 巻 4 号 p. 192-205
発行日: 2016/04/15
公開日: 2016/05/07
ジャーナル オープンアクセスWe investigated the properties of sintered porous metal filter manufactured by space holder method and we obtained the following results. (1) The porous structure with large cell wall by space holder method had larger form coefficient before and after carbon particle loading and higher trapping efficiency than there-dimensional network structure with bar-shape skeleton. (2) Form coefficient before and after carbon particle loading, trapping efficiency and trapped carbon amount to start blocking became larger or higher as the mean diameter of voids got smaller. (3) The filter composed of 3 disk filters arrayed with small space had smaller form coefficient before and after carbon particle loading, higher trapping efficiency and larger trapped carbon amount to start blocking than 1-disk filter. (4) Corn-shape filter with large filtration area had much better properties than disk filter. (5) Collecting efficiency before blocking was constant independently of trapped carbon amount if the air velocity was constant and it became higher as the air velocity increased. These results indicate that the optimization of porous structure and filter form makes it possible to develop the high-performance sintered porous metal filter with low pressure drop and high trapping efficiency by space holder method.抄録全体を表示PDF形式でダウンロード (2621K)
特集：金属ガラス・ナノ結晶材料の構造制御と応用に関する新たな展開
総説
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Akira TAKEUCHI2016 年 63 巻 4 号 p. 209-216
発行日: 2016/04/15
公開日: 2016/05/07
ジャーナル オープンアクセスThis paper provides general overviews for the recent progress in alloy designs for high-entropy crystalline and glassy alloys in the following aspects. First, the alloy designs for bulk metallic glasses (BMGs) are briefly reviewed by focusing on atomic size differences, mixing enthalpy and valence electron concentration as well, followed by their extension to the other related alloys including high-entropy alloys (HEAs). Then, the historic backgrounds of the high-entropy bulk metallic glasses (HE-BMGs) are dealt with by pointing out the features of the HE-BMGs. Subsequently, the recently-developed HEAs with hcp structure, which are the new ones to the conventional HEAs with bcc, fcc and their mixture structures, are discussed for their future development. Finally, recent alloy designs utilizing crystallographic data acquired from Pettifor map, Pearson’s Crystal Data and binary phase diagrams are discussed in order to use them for the development of new alloys in near future.抄録全体を表示PDF形式でダウンロード (1012K)
研究論文
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永瀬 丈嗣, 馬越 佑吉2016 年 63 巻 4 号 p. 217-222
発行日: 2016/04/15
公開日: 2016/05/07
ジャーナル オープンアクセスThe microstructure of rapidly solidified ((Cu0.6Zr0.3Ti0.1)1-xCox)98B2 alloy, which was designed as a combination of Cu-based Cu60Zr30Ti10 alloy with high glass forming ability and Co, was investigated by XRD, DSC and electron microscopy. An amorphous single phase can be obtained in alloys with x = 0, 0.1 and 0.2. Nano-crystalline phase dispersed amorphous phase was formed at the alloy with x = 0.3. Nano-emulsion like structure formation, which is typical solidification structure formed via liquid phase separation, was not detected in Co-Cu-Zr-Ti-B alloys, and this was explained by the negative interaction between Co-Zr, Cu-Zr, Co-Ti and Cu-Ti pairs.抄録全体を表示PDF形式でダウンロード (1082K) -
藤田 和孝, 西川 裕之, 山崎 徹, 加藤 秀実2016 年 63 巻 4 号 p. 223-229
発行日: 2016/04/15
公開日: 2016/05/07
ジャーナル オープンアクセスBulk metallic glasses (BMGs) are excellent alloys in strength, fatigue strength, fracture toughness and corrosion resistance. Therefore, the BMGs are attractive for machine and structural members. However the shear and torsional properties were not known enough. Then, we conducted the torsional tests in the BMG, and investigated the fracture and fatigue characteristics. Test Zr-based bulk metallic glass prepared by arc melting tilt casting method consisted of Zr55Cu30Al10Ni5 at.%. Shear stress-shear strain diagrams showed elastic-perfectly plastic deformation with large plastic strain and many shear bands in maximum shear stress directions, regardless of the differences between the test specimen diameters, lengths, magnitude of Rs at the end of parallel part. The fatigue limit in torsional fatigue test τW and fatigue ratio τW/τB (τB = torsional strength ) were 650 MPa and 0.59, respectively. The fatigue crack initiated at the specimen surface in the maximum shear stress direction and propagated in the normal direction for the maximum tensile stress with striation like patterns.抄録全体を表示PDF形式でダウンロード (2020K) -
山崎 徹, 山田 昌弘, 藤田 和孝, 加藤 秀実, Do Hyang Kim2016 年 63 巻 4 号 p. 230-238
発行日: 2016/04/15
公開日: 2016/05/07
ジャーナル オープンアクセスZr-Cu-Ni-Al bulk metallic glasses (BMGs) have been limited in practical applications because of their low ductility under tensile and compressive testing conditions. This may be due to the formation of highly localized shear bands during plastic deformation. In this study, effects of Pd, Pt, Au and Ag additions on mechanical properties of Zr-Cu-Ni-Al BMGs have been examined. By the noble metal additions, precipitation of the icosahedral quasicrystal phase (I-phase) in the supercooled liquids was observed. Compression tests were carried out in these BMGs at an initial strain rate of 1 × 10−4 s−1 at room temperature. Especially, in the case of the Au-addition, large plastic deformation was observed and many shear bands were also observed in wide region of the side-surface of the fractured specimens. This may be due to dynamic precipitations of nanocrystalline particles inside the shear bands during compressive deformation that prevent the propagations of the deformation shear bands.抄録全体を表示PDF形式でダウンロード (4985K)
本会記事
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2016 年 63 巻 4 号 p. Pref4_1-
発行日: 2016/04/15
公開日: 2016/05/07
ジャーナル オープンアクセスPDF形式でダウンロード (133K) -
2016 年 63 巻 4 号 p. MtgPr4_1-MtgPr4_21
発行日: 2016/04/15
公開日: 2016/05/07
ジャーナル オープンアクセスPDF形式でダウンロード (819K) -
2016 年 63 巻 4 号 p. 249-250
発行日: 2016/04/15
公開日: 2016/05/07
ジャーナル オープンアクセスPDF形式でダウンロード (226K) -
2016 年 63 巻 4 号 p. 239-248
発行日: 2016/04/15
公開日: 2016/05/07
ジャーナル オープンアクセスPDF形式でダウンロード (2271K)
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