材料
Online ISSN : 1880-7488
Print ISSN : 0514-5163
ISSN-L : 0514-5163
15 巻 , 149 号
選択された号の論文の8件中1~8を表示しています
  • 栄 幸雄
    1966 年 15 巻 149 号 p. 57-67
    発行日: 1966/02/15
    公開日: 2009/06/03
    ジャーナル フリー
  • 松島 成夫
    1966 年 15 巻 149 号 p. 68-74
    発行日: 1966/02/15
    公開日: 2009/06/03
    ジャーナル フリー
    前報告の高温真空引張疲労試験機 (真空度10-5mmHg, 最高試験温度700℃) を用いて, Cu-Al (2%Alおよび7%Al) 合金の高温真空引張疲労試験を行なった. そして, その疲労破壊寿命ならびに疲労変形の温度依存性を調べた. その結果, 次のようなことがわかった.
    (1) 破壊までの繰返し数, 試験温度をN, Tとすると, 一般に, (-dlogN/dT) は荷重が大きくなるに従って減少し, 試験温度が高くなると増加する. そして, N>103のとき, 7%Al合金の (-dlogN/dT) は2%Al合金のそれより大きい.
    (2) 2%Alと7%Al合金のN, Tが等しくなる繰返し荷重は, 7%Al合金のほうが約1.6倍2%Al合金より大きい.
    (3) 2%Al合金, 7%Al合金の短いすべり線は, 400℃以下の温度で生ずる. そして, 2%Al合金のその破壊までの変形は, 試験温度が高くなると減少し, 7%Al合金では増加する.
    (4)〔(荷重繰返し数-0.2N)/(0.8N-0.2N)〕-〔(変形-0.2Nの変形)/(0.8Nの変形-0.2Nの変形)〕曲線が占める位置は荷重繰返し数が大きくなると高くなっていく. 7%Al合金に関するその曲線位置は試験温度が高くなるに従って下降する. そして, 2%Al合金のほうは, 300℃まではいくぶん上昇し, 300℃を過ぎると7%Al合金のときのように下降する.
    (5) dε/dN (最小値) とNの関係は, 試験温度や荷重条件のいかんを問わず,
    log(dε/dN)=AlogN+B
    A≅6/5, B≅0.2
    であった. ただし, εは変形, Nは荷重繰返し数である.
  • 植村 幸生, 山城 貞男, 小林 政治郎
    1966 年 15 巻 149 号 p. 75-80
    発行日: 1966/02/15
    公開日: 2009/06/03
    ジャーナル フリー
    最近プラスチック材料の利用が広まるにつれ, そのかたさ試験も行なわれるようになった. その現状と問題点を明らかにするため, ブリネルおよびロックウェルかたさ試験に関する実態調査を行なった. その結果次のようなことが明らかになった.
    ブリネルかたさ試験: その使用試験機には古いものが多い. その実測値の現状は社会的に通用しうる状態ではない. その相互差の最大の原因はくぼみ径の読み取り誤差にある. その統一のためには, 試験機のJISに従っての整備とくぼみ径の妥当な測定方法の確立とが必要である.
    ロックウェルかたさ試験: その使用試験機には新しいものが圧倒的に多い. その実測値はまだ満足できる状態にはないが, 機差と測定時の温度差とを補正すればある程度一致した値が得られる. その統一のためには, プラスチック材料を対象とした試験機および試験方法に関するJISを確立する必要がある. また鋼球圧子のホルダにはかなりの不良品があり, それから生ずるかたさ値の誤差は相当大きいので充分注意する必要がある.
  • 吉沢 武男, 菊池 庸平, 堀 幸夫, 寺沢 正男, 師岡 利政, 本多 達三
    1966 年 15 巻 149 号 p. 81-87
    発行日: 1966/02/15
    公開日: 2009/06/03
    ジャーナル フリー
    The nonferrous material that is fit for standard block of hardness for industrial purpose is at present 7-3 brass. But it is inefficient at lower hardness because its variation range gets extensively scattered then.
    The present research was conducted to control the hardness of brass and its variation range by replacing some of its zinc contents with such metals as beryllium, manganese, aluminium, and silicon, under various draft of cold rolling and heat treatment.
    Stable hardness could be attained around HRB 30 with controlling zinc content of lower hardness materials to 3∼5%. The added elements are in the range of 0.3∼1.0%. These ternary alloys are constructed with α-phase only, of which the standard composition is shown in Table I. The working process of homogenizing, initial rolling, intermediate annealing, final rolling, final annealing, etc. is respectively shown in Table II.
    The research has proved that beryllium is the most effective as additive element, and aluminium and manganese come after it with their variation range of hardness at around HRB 30∼40.
  • 上田 太郎, 田中 政夫
    1966 年 15 巻 149 号 p. 88-94
    発行日: 1966/02/15
    公開日: 2009/06/03
    ジャーナル フリー
    In order to study the effects of age and of heat-treatment etc., after rolling, on the repeated impact tensile strength of rolled screw bolts, we have conducted repeated impact tensile test of 3"/8 rolled screw bolts, made of SS41-, S55C-and SCM3-steels.
    The results obtained are outlined as follows.
    (1) The repeated impact tensile strength of rolled screw bolts is larger than that of cut screw bolts.
    (2) The age increases the repeated impact tensile strength of rolled screw bolts made of SS41-steel, after rolling.
    (3) The heat-treatment (quenched and tempered) decreases the repeated impact tensile strength of rolled screw bolts remarkably after rolling.
    (4) The screw rolling increases the repeated impact tensile strength of heat-treated screw bolt made of SCM3-steel, after heat-treatment.
    (5) The hot dip zinc plating decreases the repeated impact tensile strength of heat-treated screw bolts slightly after heat-treatment.
  • 青木 逸郎, 国尾 武, 中村 宏
    1966 年 15 巻 149 号 p. 95-101
    発行日: 1966/02/15
    公開日: 2009/06/03
    ジャーナル フリー
    Many studies have hitherto been published on multiple repeated stress tests, most of which are based on the final fatigue fracture consideration. The research on the fatigue has mainly been made in consideration of the effect of repeated cycle stress based on the number of cycles and stress amplitude at final fracture. In this report the auther tries to take into account not only the failure point but also, and still more, the crack initiating point and the crack propagation process. This report is intended then to show the progress of fatigue in two separate steps, first up to the crack initiation period and then during the crack propagation period. The test has been made by means of a rotary bending fatigue testing machine, using as specimen a low carbon steel (0.17%C) bar with a V shaped notch.
    The results obtained are as follows in brief.
    (1) In the test of constant stress amplitude, the rate of crack propagation dλ/dN is low when the crack is initiated, then it shows a sudden increase after a certain depth of the crack is attained. This may be attributed to the stress concentration on the crack which begins to show crack-tip.
    (2) The effect of the repeated cycle stress prior to initiation of the crack on the width of the crack and the number of the crack initiating cycle seems to follow the linear damage law.
  • 五十嵐 秀二, 柏原 茂, 岡崎 清
    1966 年 15 巻 149 号 p. 102-107
    発行日: 1966/02/15
    公開日: 2009/06/03
    ジャーナル フリー
    This paper describes the sintering process of ferrites under hot pressing and their magnetic properties. Bulk density ρ and grain growth aspect were investigated as a function of the maximum firing temperature Tm and the hot pressing pressure at Tm (Ph) in the case of Ni0.3 Zn0.7 Fe2O4 and Cu0.4 Zn0.6 Fe2O4 and compared hot pressed specimen with the specimen obtained by conventioned firing method. From ρ-Tm curves of CuZn and NiZn ferrite, we can see that the specimen prepared by the conventional method shows anomalous expansion in the sintering process. However, in the case of hot pressing, no expansion phenomenon was observed and the densification was considerably promoted. As the result, we could obtain the specimen with same density as the conventionally sintered one under hot pressing at lower temperature by 200°C than the ordinary firing. The effect of hot pressing on grain growth was examined by means of an electron microscope. The result shows that hot pressing greatly obstructs grain growth. The magnetic properties of the hot pressed ferrite differed from that of the ordinary fired ferrite. Especially, in the NiZn ferrite, the decrease of initial permeability μ and altered temperature characteristic of μ were the result of hot pressing. And, in the hot pressing case, lower maximum flux density Bs and higher coercive force Hc were also obtained as compared with that prepared by the conventional method. Measurement on the ferromagnetic resonance was carried out on NiZn specimen at 6790Mc. From this result we can see that the static magnetic field required for resonance Hc decreases and the magnitude of line width ΔH increases considerablly by hot pressing.
  • 粟谷 丈夫, 橋本 正彦
    1966 年 15 巻 149 号 p. 108-113
    発行日: 1966/02/15
    公開日: 2009/06/03
    ジャーナル フリー
    In order to study the effects of irradiation on the surface layer of polyethylene samples, %-crosslinking and gel-fraction of test pieces shaved down to the various thickness after irradiation were measured by means of a vibrating reed method and a Soxhlet extractor respectively. And then, the values of %-crosslinking and gel-fraction on each layer were calculated. Although, at the internal layer, the linear relation between (1-g)+√1-g and 1/R has held as predicted by the theory of solubility, but approaching the surface, this linearity has not held for samples irradiated in air. Moreover Young's moduli on the surface have behaved non-lineally for the dose. These results, however, could be comprehended if the proportion of the main chain unit fractured were not proportional to the irradiation dose on the surface. The value of r/2c, the ratio of the unit fractured to one crosslinked reached 1.5 on the surface, about 3 times the value in the internal layer. Even on the layer near the surface where r/2c is larger than unity, a considerable degree of gel-formation took place. By using the data of Young's modulus and gel-fraction measurements, the initial number average molecular weight may be estimated.
feedback
Top