著者
布施 洋一
出版者
社団法人日本材料学会
雑誌
材料 (ISSN:05145163)
巻号頁・発行日
vol.43, no.492, pp.1181-1182, 1994-09-15
著者
妹尾 允史
出版者
社団法人日本材料学会
雑誌
材料 (ISSN:05145163)
巻号頁・発行日
vol.41, no.462, pp.396-397, 1992-03-15
著者
西原 正夫 西原 守 山本 俊二
出版者
社団法人日本材料学会
雑誌
材料試験 : journal of the Japan Society for Testing Materials (ISSN:03727971)
巻号頁・発行日
vol.10, no.90, pp.168-173, 1961-03-15

Compression-creep data for zircaloy 2, Mo-Cu-Zr alloy and 18-8 stainless steel were obtained at room temperature, 250℃, 316℃ (600゜F) and 450℃ for a period of 100 hours. Zircaloy 2 and Mo-Cu-Zr alloy were casted respectively as ingot by the consumable-electrode double-arc melting. The test specimens were machined from a bar obtained from the ingot by forging, and annealed at 700℃ (Zircaloy 2) and 750℃ (Mo-Cu-Zr alloy) for 1 hour in vacuum furnace. The test equipment for compression creep is the conventional tension creep machine with a fixture consisted of two yokes which convert tensile loading into compressive loading. The fixture used is of the similar type to the one developed at the Westinghouse Research Laboratory by M.J. Manjoine. The compression-specimen which has a diameter of 12 mm and an overall length of 36 mm was compressed between two seats, the ends of the specimen and of the seats being ground and lapped. The relative displacement of the yokes was measured by dial gauge extensometer as a measure of the strain in the specimen. For checking the magnitude of instantaneous strain in creep tests, short-time tension and compression tests were made for zircaloy 2 and Mo-Cu-Zr alloy at 316℃ by using the test equipment above-mentioned. The continuous loading was given by moving a running weight sliding on the loading lever arm of the creep machine. Although at room temperature zircaloy 2 and Mo-Cu-Zr alloy have smaller instantaneous and creep strain in comparison with 18-8 stainless steel which displays appreciable creep at room temperature, they tend to have poorer creep resistance at higher temperatures, and the steady-state creep component becomes conspicuous for Mo-Cu-Zr alloy at 316℃ and for zircaloy 2 at 450℃. The creep strength of Mo-Cu-Zr alloy at 450℃ is stronger than that of zircaloy 2 when the stress level is below 17 kg/mm^2. Comparison of tension-creep and compression-creep properties for Mo-Cu-Zr alloy (at 316℃ and 450℃) show that the alloy has poorer resistance in compression than in tension within a certain limit of stress, above which an effect of decrease of stress resulted from the increase of cross-section of a compression specimen would appear. The similar phenomena for S 816 and nimonic 90 at 1600゜F have been reported by L.A. Yerkovich. This difference in creep-resistance may partly be explained by the anomalous variation of the stress-strain relationship in tension and compression. But it should be taken into account as well that the bedding-down of the ends of compression-specimen and the anisotropic effects in the resistance to deformation produced in the process of preparing the test specimen are related to the difference in creep-resistance, although in our experiment the bedding-down of the compression specimen was minimized by lapping the ends of compression specimen.
著者
三木 光範
出版者
社団法人日本材料学会
雑誌
材料 (ISSN:05145163)
巻号頁・発行日
vol.37, no.414, pp.354-355, 1988-03-15
著者
熊倉 郁夫
出版者
社団法人日本材料学会
雑誌
材料 (ISSN:05145163)
巻号頁・発行日
vol.52, no.5, pp.552-553, 2003-05-15
参考文献数
6
著者
荒川 正文
出版者
社団法人日本材料学会
雑誌
材料 (ISSN:05145163)
巻号頁・発行日
vol.16, no.164, pp.319-321, 1967-05-15
被引用文献数
2

粉体粒子の付着、凝集の程度を知るためにいくつかの方法が試みられているが、その中で粉体充てん層のせん断応力と荷重の関係からクローン式により粒子間凝集力を測定する方法を試みた。この方法で得られる凝集力はせん断面あたりの力であるが、これに充てん層の空隙率、試料粒子の平均粒子径、粒子1個に対する隣接粒子の平均接触点数を考慮すれば粒子接触点1個の凝集力を計算することができる。粒度の異なった数種のホワイトアランダムを試料としてこの方法で粒子径と粒子間凝集力の関係を調べた。その結果、この試料では脂肪酸処理による粒子の表面の疎水化の効果はほとんど認められない。また、粒子径が小さくなるほど凝集力も減少するが、その力は吸着層を伴ったvan der Waals力の範囲である。しかし、van der Waals力による凝集力は粒子径に比例するといわれるが、この実験では微粒子では粒子径が1/10になると凝集力が1/100程度になった。これは、充てん層のせん断面あたりの凝集力を粒子接触点1個あたりに換算するときに用いたRumpfの仮定に誤りがあると考え、実験結果から逆に補正をすると高空隙率充てんの微粉体では粒子1個の平均接触点数が約2.3となり、微粒子の凝集は珠数状の連りで、かさ高い網状構造を形成していることが推定される。
著者
佐藤 千之助 車田 亮 岩城 英彦 小松 靖門
出版者
社団法人日本材料学会
雑誌
材料 (ISSN:05145163)
巻号頁・発行日
vol.35, no.397, pp.1144-1150, 1986-10-15
被引用文献数
1

Two kinds of carbon felt reinforced carbon composite of pitch fiber (C/C-A) and of PAN fiber (C/C-B) have been developed to improve the fracture mechanics properties of regular grade graphite. The tensile properties and the fracture toughness values of these new composites were determined as function of temperature up to 2400℃. These results were compared with those of a carbon fiver cloth reinforced carbon composite of rayon fiber (C/C-C) and fine grain isostatic graphite (IG-11), and these distinctive features were discussed.
著者
池田 豊
出版者
社団法人日本材料学会
雑誌
材料 (ISSN:05145163)
巻号頁・発行日
vol.17, no.180, pp.783-792, 1968
被引用文献数
1
著者
関野 登 井上 雅文 山内 秀文
出版者
社団法人日本材料学会
雑誌
材料 (ISSN:05145163)
巻号頁・発行日
vol.50, no.4, pp.415-420, 2001-04-15
参考文献数
18
被引用文献数
1

Mechanical properties of particleboards such as surface hardness, modulus of elasticity (MOE), bending strength (MOR) can be improved by high densification of its face layers. One of the effective ways for this purpose is introducing a steam pre-treatment technique into preparations of wood furnish for face layers, because steaming wood at high temperature increases wood compressibility. Also steam treated and then compressed particles show much less irreversible swelling than ordinary particles. This excellent dimensional stability would contribute to reductions of panel thickness swellings.<br>Three-layered particleboards with a density ranging 0.5-0.8g/cm<sup>3</sup>, a face to core ratio of 2/3, and a thickness of 12mm were manufactured from Sugi (<i>Cryptomeria japonica D. Don</i>) face strands (75mm&times;9.0mm&times;0.67mm) and core particles (14.9mm&times;2.9mm&times;0.97mm). The face strands were steam pre-treated in an autoclave by introducing high pressure steam at 210&deg;C for 10 minutes. Phenol-formaldehyde resin was used as a binder. The manufactured panels showed the following characteristics, when compared to control panels with non-treated face strands: 1) the maximum density through the thickness increased by 10-15 percent, 2) surface hardness increased by 30 percent, 3) thickness swellings were greatly improved, this being pronounced at higher density panels, 4) however, the reduction of linear expansion was not obvious because this layer structure showed excellent resistance against for in-plane swelling, 5) in spite of face layer's high densification, MOE and proportional limit stress in bending were almost the same as the controls, 6) MOR and withdrawal resistance of wood screw decreased at most by 30 percent due to the reduction of wood cohesion itself caused by steaming.
著者
新井 義夫 上谷 長俊
出版者
社団法人日本材料学会
雑誌
材料 (ISSN:05145163)
巻号頁・発行日
vol.15, no.152, pp.291-293, 1966-05-15

The colored smoke trails from jet planes are generated by volatilizing colored smoke oils with hot exhaust gases from the jet engines. The colored smoke oil is a slurry, which is a mixture of selected dye with petroleum base oil. The colored smoke oil is a non-Newtonian fluid subject to the following power law. S=η' D^n where S is the shearing stress, D the rate of shear, η' the consistency index, and n the flow-behavior index. The following experimental equations were derived at low rates of shear. η'=η_0 exp (kC) (k>0) n=exp (-k'C) (k'>0) where η_0 is the viscosity of the base oil, C is the concentration of the dye, and k and k' are the constants to the kinds of dyes.
著者
三沢 俊平 末高 洽 下平 三郎
出版者
社団法人日本材料学会
雑誌
材料 (ISSN:05145163)
巻号頁・発行日
vol.19, no.201, pp.537-542, 1970-06-15
被引用文献数
2

The oxidation processes of Fe (II) hydroxo-complexes to α-, β-, γ-, andδ-FeOOH and Fe_3O_4 in aqueous solutions were investigated by processing measurements with infrared, far infrared, and Mossbauer spectra and X-ray diffraction of oxidation products. The effect of oxidation rate and addition of Cu^<2+> or PO_4^<3-> ion on the oxidation of Fe (II) hydroxo-complexes were also studied. It has been found that in the present experimental condition the process of oxidation depends on the pH-value of solution as follows : in basic solution (pH12.5〜13.5) Fe(OH)_2&roarr;α-FeOOH, in the slightly acidic solution (pH6〜6.5) β-Fe_2(OH)_3Cl&roarr;Green rust I&roarr;γ-FeOOH, and in neutral or slightly basic solution (pH7〜8) Fe(OH)_2&roarr;Fe_3O_4 and β-Fe_2(OH)_3Cl&roarr;Green rust I&roarr;Fe_3O_4. The infrared spectra of Fe(OH)_2 and Green rust I, an oxidation intermediate, have been obtained. The rapid oxidation of Fe(II) hydroxo-complexes in solutions with the addition of H_2O_2 results in the formation of δ-FeOOH. The oxyhydroxide has also been obtained by removing water from the Fe (II)-complexes, and leaving them in air to be oxidized. The broad absorption band at 450 cm^<-1> has been shifted for 480 cm^<-1> with the increase in size of δ-FeOOH crystallite formed by the oxidation of Fe(OH)_2 with H_2O_2. In the presence of Cu^<2+> or PO_4^<3-> ion, freshly precipitated Fe(II) hydroxo-complexes are oxidized into amorphous δ-FeOOH with air in solutions. This transformation is considered to have been caused by the catalytic effect Cu^<2+> or PO_4^<3-> ion in the oxidation of Fe(II)-complexes.
著者
谷本 敏夫 網島 貞男 石川 浩
出版者
社団法人日本材料学会
雑誌
材料 (ISSN:05145163)
巻号頁・発行日
vol.28, no.304, pp.40-46, 1979-01-15
被引用文献数
2

Fatigue tests have been conducted to investigate the fatigue properties of various types of laminated composites and some statistically meaningful inference was drawn from these results. The materials used in the experiment were 4 different kinds of FRP laminates, satin woven FRP, plain woven FRP, roving woven FRP and SMC laminated FRP. Sufficient approach based on the Weibull distribution was applied to the test data to evaluate the dispersion in the fatigue life of the materials. The dependences of fatigue life and its dispersion on the applied stress level, specimen size and fiber content in the specimen were discussed. The test results showed a wider experimental scatter particularly at the life range of 10^5 to 10^6 cycles than that observed on conventional metallic material. Thus it is emphasized that a larger reduction of design life is necessary for FRP to assure the same level of confidence and reliability as other materials.
著者
孫 峰 岩本 正治 自念 榮一 鈴木 惠
出版者
社団法人日本材料学会
雑誌
材料 (ISSN:05145163)
巻号頁・発行日
vol.38, no.427, pp.360-366, 1989-04-15
被引用文献数
2

The fracture mechanisms of plain woven fabric laminated composites were studied by load-displacement curves, AE behavior, and macro- and micro-observations in tensile tests. The results obtained are as follows: (1) The failure processes which are accumulative can be divided into three stages on the load-displacement curves of the composites. The stage I is elastic. In the stage II, the debonding in weft takes place. The stage III mainly corresponds to the matrix cracking and the separation between wefts and warps. They depend on the weave structure strongly but are related little with the ply number of laminates. (2) The boundaries of the stages I to II and II to III have some relations to the point where the AE event count rate can be detected first and the point where the rate increases rapidly, and thus the dominant failure mode can be well traced from the patterns of the AE event count rate and the AE energy curve.
著者
竹村 哲男 黒木 仁昭
出版者
社団法人日本材料学会
雑誌
材料 (ISSN:05145163)
巻号頁・発行日
vol.13, no.128, pp.399-403, 1964-05-15

Crystalline polymers show non-linear viscoelastic properties at very low excitations compared with amorphous polymers. It is very difficult to discuss the non-linear viscoelasticity generally, However, the degree of non-linearity has been defined at the temperature region where the dispersion due to crystal is important, as a result of considerations based on simple mechanical model and phenomenological method. The temperature dependency of this degree of non-linearity has been examined by making experiments of stress relaxation for high and low density polyethylenes and polyethylenet erephthalate. The result is that the degree of non-linearity is related to the dispersions closely, that is, the degree of non-linearity has larger values at the starting points of each dispersion. These facts suggest that the interaction between different dispersions will be the main factor for the non-linear viscoelastic mechanism.
著者
加藤 容三 広瀬 素尚 長谷川 典彦 片山 勲
出版者
社団法人日本材料学会
雑誌
材料 (ISSN:05145163)
巻号頁・発行日
vol.33, no.373, pp.1264-1270, 1984-10-15

Rotating bending fatigue tests were made on a quenched and tempered 0.45% carbon steel in the temperature range from room temperature to 450℃ at a machine speed of 3600 rpm. The fatigue strength σ_f at 4×10^4 to 3×10^7 cycles reached a maximum at about 350℃ due to cyclic strain aging in the same manner as the annealed material. For the quenched and tempered material the fatigue limit was clearly confirmed up to 200℃ but not observed at the peaking temperature of 350℃, while for the annealed material the fatigue limit had been confirmed even at 350℃. the fatigue strength of the quenched and tempered material was higher than that of the annealed material at every temperature, but the effect of cyclic strain aging on fatigue strength of the former was less than that of the latter. This suggests that this material shows different effect of cyclic strain aging at high temperatures when heat treated differently. The observation of fatigue crack propagation behavior revealed that the strain aging at 350℃ is more effective for the quenched and tempered material in preventing crack initiation rather than inhibiting crack propagation, contrary to the results of the annealed materials, which shows that strain aging is more effective in inhibiting crack propagation.