巻号一覧
後続誌
67 巻, 9 号
選択された号の論文の7件中1～7を表示しています
- |<
- <
- 1
- >
- >|
研究論文
-
岸武 勝彦, 恵良 秀則, 大坪 文隆, 長谷川 哲也1995 年 67 巻 9 号 p. 613-618
発行日: 1995/09/25
公開日: 2011/06/11
ジャーナル フリーEutectic Fe-10 mass % Cr-10 mass % Mo alloys with different C/B ratio were rapidly solidified into ribbons by means of a single roller method to obtain the amorphous phase. Crystallization behavior and hardness change by tempering of the amorphous alloys were investigated by differential thermal analysis, X-ray diffraction analysis, transmission electron microscope observation and knoop hardness test. The crystallization of the amorphous phase in carbon-rich alloys proceeded at lower temperatures upon tempering, compared with that in boron-rich alloys. All the alloys exhibited a high hardness of 1400 to 1500 HK 0.5 after crystallization. The carbon-rich alloys possessed a larger amount of boro-carbides after crystallization than the boron-rich alloys, bringing about a markedly high hardness even after tempering at high-temperatures around 1200 K. The alloys, the C/B ratio of which was nearly epual unity, kept a hardness of 1400 to 1500 HK 0.5 in a wide temperature range after crystallization. This is attributed to formation of nano-structure of ferrite and boro-carbide of M23X6 (M : metals, X : C and/or B).抄録全体を表示PDF形式でダウンロード (653K) -
米田 隆志, 佐藤 敬, 新山 英輔1995 年 67 巻 9 号 p. 619-625
発行日: 1995/09/25
公開日: 2011/06/11
ジャーナル フリーThe relative stability of mold materials for the casting of titanium was evaluated in relation to the formation of alpha-case. Oxide molds examined were those made of CaO, CeO2, La2O3, Y2O3 and ZrO2 powders bonded with ethanol solutions of respective chloride or oxychloride to avoid mold contamination by binders. Machined graphite mold was used for comparison. Six molds made of different materials were stacked and poured in one operation in order to eliminate the influence of variations in pouring temperature and cooling rate. The extent of surface reaction of castings was determined by optical metallography and microhardness profiles. The effects of ethyl silicate, zirconium oxychloride, calcium nitrate and calcium chloride as binder on the reactivity and moldability of CaO were compared. The results showed that castings made of CeO2, ZrO2 and graphite molds had clear alpha-case, whereas negligible reaction with titanium occurred in CaO, La2O3 and Y2O3 molds. CaO is regarded as a promising mold material, provided that a binder with sufficient chemical stability against titanium at high temperature is developed.抄録全体を表示PDF形式でダウンロード (1075K) -
久保田 耕平, 佐藤 勉, 二宮 隆二, 尾城 武司1995 年 67 巻 9 号 p. 626-631
発行日: 1995/09/25
公開日: 2011/06/11
ジャーナル フリーFor developing high-strength Zn alloys, Zn-10 Al-X Cu-0.02 Mg (X=0∼14) alloys were examined. Cu 7 % in Zn-10 Al is on the eutectic line and showed fluidity as high as ZAS (Zn-4 Al-3 Cu-0.04 Mg) which was a commercial alloy for molds. Therefore the casting temperature of Zn-10 Al rich in Cu was consequently low. For example, the casting temperature and tensile strength of ZAS were 703 K and 215 MPa respectively. On the other hand, the casting temperature of Z 1009 (Zn-10 Al-9 Cu-0.02 Mg) was the same as ZAS, 703 K. Moreover, the tensile strength of Z 1009 was 360 MPa, which was 67 % higher than that of ZAS.抄録全体を表示PDF形式でダウンロード (758K) -
多田 周二, 高橋 利夫, 阿部 利彦1995 年 67 巻 9 号 p. 632-637
発行日: 1995/09/25
公開日: 2011/06/11
ジャーナル フリーThe temperature-difference treatment during austempering produces a new type of ADI which has graded mechanical properties. By controlling its mechanical properties to suit the desired requirements, this material, named FGADI, is expected to prove useful in an extensive number engineering applications. In this study, we investigated the effects of radial temperature gradient on the mechanical properties of an ADI ring, with the particular aim of replacing a solid cylinder with a hollow one so as to lighten the weight of the end product. We demonstrated the radial temperature difference produces an ADI ring with mechanical properties superior to those produced using uniform temperature treatment.抄録全体を表示PDF形式でダウンロード (680K) -
駒崎 徹, 丸山 善則, 西 直美1995 年 67 巻 9 号 p. 638-644
発行日: 1995/09/25
公開日: 2011/06/11
ジャーナル フリーThe effects of primary silicon diameter on the wear characteristics of cutting tool (K10) for JIS-ADC 14 diecastings were investigated in samples fabricated by a 90 metric ton locking force cold chamber type die casting machine. The microstructures of ADC 14 diecastings consist of primary silicon, Al-Si eutectic and α phase. Moreover, coarse primary silicon particles over 23 μm in microstructure were observed with the shot-time-lag increased and pouring temperature decreased. When the amount of coarse primary silicon was small cutting tool wear was slight. On the other hand, cutting tool wear became heavy with increasing amount of coarse primary silicon. The wear type changed from adhesive wear to abrasive wear due to intermixed coarse primary silicon in diecastings.抄録全体を表示PDF形式でダウンロード (843K) -
田中 雄一, 楊 忠亮, 宮本 一道, 長船 康裕, 上出 英彦1995 年 67 巻 9 号 p. 645-651
発行日: 1995/09/25
公開日: 2011/06/11
ジャーナル フリーThe effects of microstructural parameters on tensile properties and fatigue limit of ferritic s. g. iron and other s. g. irons with various matrix structures were systematically investigated in this study. The quantitative relationship between fatigue limit and structural factor such as graphite nodule size and matrix structure (i. e., hardness) was clarified, and the prediction equations of fatigue limit of s. g. iron were proposed. The main results obtained were as follows : (1) The prediction equations of the fatigue limit of ferritic s. g. iron were given below : σw=550.7/dmax0.19, σw=457.8/d0.29, where dmax and d were the maximum graphite nodule size and mean graphite nodule size, respectively. (2) The same type of equation as shown below was also used as the prediction equation of other s. g. irons : σw= C/dA, where C and A were experimental constants. The slope of the fatigue limit versus d was increased as matrix hardness for each cast iron with different matrix hardness. (3) The prediction equations of the fatigue limit which was applicable to various s. g. irons with different matrix structures were given as follows : For other irons excepting ADI ; σw=1.80HV/dmaxC⋅HV (r=0.96), where C was experimental constant, 0.47 × 10-3. For ADI ; σw=2.45HV/dmaxC⋅HV (r=0.97), where C was 0.54 × 10-3.抄録全体を表示PDF形式でダウンロード (777K) -
清水 一道, 野口 徹, 鎌田 誉史, 谷野 祐一1995 年 67 巻 9 号 p. 652-657
発行日: 1995/09/25
公開日: 2011/06/11
ジャーナル フリーIn order to clarify the erosion mechanism of spheroidal graphite cast iron, the authors carried out erosion tests and observed the continuous structural change in the vertical section near the surface. The erosion of spheroidal graphite cast iron progresses as follows : (1) the spheroidal graphites on the surface layer deform gradually (2) lips grow in the impact direction (3) they expand and drop out. Although the erosion progresses with the repetition of lip-growth and dropping out, the cycle differs depending on the materials. The wear rate, which serves as the standard cycle of lip-growth and dropping out, decreases as the pearlite ratio increases and corresponds well to the erosion rate. We also confirmed that our continuous observation method is practical and useful for elucidating the erosion mechanism.抄録全体を表示PDF形式でダウンロード (846K)
- |<
- <
- 1
- >
- >|