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65 巻, 1 号
選択された号の論文の9件中1～9を表示しています
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研究論文
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小林 慶三, 高柳 猛, 三輪 謙治1993 年 65 巻 1 号 p. 3-7
発行日: 1993/01/25
公開日: 2011/06/22
ジャーナル フリーThe Ti-34 mass % Al molten alloy was held in the crucibles made of Y2O3, ZrO2, and Y2O3 added ZrO2 (amount of added ZrO2 changed to 20 mass %, 40 mass %, 60 mass %, 80 mass %) at 1823 K for 1.2 ks in Ar gas atomosphere, Then the reaction between the molten alloy and the crucible was studied by microscopical examination, hardness test, electron probe microanalysis and X-ray diffraction method. From this experiment, the following results are obtained : (1) The hardness of Ti-Ai alloy specimens obtained after melting raises with increasing in the amount of added ZrO2 in the crucibles. (2) Zr3Y4O12 forms in the crucible made of Y2O3 contained ZrO2 more than 60 mass % after melting. (3) In the case of the crucible made of Y2O3 contained ZrO2 less than 40mass %, the reaction becomes sluggish with decreasing of ZrO2 content.抄録全体を表示PDF形式でダウンロード (687K) -
遠嶋 雅徳, 府川 和弘, 丹羽 直毅, 鈴木 俊夫1993 年 65 巻 1 号 p. 8-12
発行日: 1993/01/25
公開日: 2011/06/22
ジャーナル フリーWe have developed a pattern recognition system for graphite shapes in cast irons using neural networks. The system is composed of two neural networks, which are a feature extraction network using the self-organization algorithm and a recognition network using the back propagation algorithm. Microscopic images were pre-processed to binay images with 32 × 32 pixels. Input data to the feature extraction network are local area patterns with 3 × 3 pixels cut out from the image data. The network extracts 25 feature patterns from the input data. After self-organization, histogram data of feature patterns for each image datum are made using the feature extraction networks. The recognition network learns the histogram data and recognizes the categories. Using the system, we discriminated between nodular graphite and flake graphite, and obtained the rate of correct answer higher than 95 %.抄録全体を表示PDF形式でダウンロード (559K) -
高橋 利夫1993 年 65 巻 1 号 p. 13-18
発行日: 1993/01/25
公開日: 2011/06/22
ジャーナル フリーThe X-ray diffraction method can be applied to the measurement of the carbon concentration of retained austenite in austempered ductile iron (ADI). The diffraction line profile is fitted by the Pseudo-Voigt function using a nonlinear least squares method, and is separated into the lower and the higher carbon containing part. At the early stage of the isothermal transformation, there was a region where low and high carbon austenite were mixed. The result suggests that the first stage of the transformation can be divided into two steps ; one is where the ferrite supersaturated with carbon forms from the parent austenite, and the other the low-carbon austenite is changed into the high-carbon or stable austenite by the carbon diffusion from the ferrite. This first stage finishes when all the austenite becomes the stable austenite, and the volume depends on the austempering temperature.抄録全体を表示PDF形式でダウンロード (669K) -
田中 武雄, 那須 三郎, 石原 慶一, 新宮 秀夫1993 年 65 巻 1 号 p. 19-24
発行日: 1993/01/25
公開日: 2011/06/22
ジャーナル フリーMechanical alloying (MA) and mechanical grinding (MG) have been performed for Fe86C14 powders by a conventional ball-mill. MA has been carried out on a mixture of elemental iron and graphite powders and MG on a pre-alloyed iron-cementite powder. Ball-milled powders have been examined by scanning electron microscopy, transmission electron microscopy, X-ray diffractometry, 57Fe Mössbauer spectroscopy and differential scanning calorimetry. Super-saturated solid solution of α-iron has been formed by a cold-welding of the pulverized iron particles on the MA process. By subsequent milling and/or heating, carbide has been formed from the solid solution. While, ultra-fine structure with capital size of few nano-meter has been formed for MG powder of the white cast iron. Amorphous phase has been formed by both MA and MG.抄録全体を表示PDF形式でダウンロード (860K) -
田中 武雄, 那須 三郎, 石原 慶一, 新宮 秀夫1993 年 65 巻 1 号 p. 25-30
発行日: 1993/01/25
公開日: 2011/06/22
ジャーナル フリーMechanical alloying (MA) has been performed for a mixture of elemental iron and graphite powders by the conventional type ball-mill. Solid state reaction of Fe3C formation has been studied for Fe83C17, Fe75C25 and Fe71C29 powders by transmission electron microscopy, X-ray diffractometry, 57Fe Mössbauer spectroscopy and differential scanning calorimetry. The amorphous phase coexistent with α-Fe has been formed after 200 hour MA. After subsequent milling, these phases have been transformed into Fe3C carbide through Fe7C3-like carbide. While, the successive reaction from Fe5C2 to Fe3C has been also confirmed in the process of heating the amorhous phase coexistent with α-Fe.抄録全体を表示PDF形式でダウンロード (722K) -
高森 晋, 新山 英輔1993 年 65 巻 1 号 p. 31-35
発行日: 1993/01/25
公開日: 2011/06/22
ジャーナル フリーThere is a period of expansion when ductile iron castings are solidifying. Nevertheless, shrinkages are often observed. The size of neck is one of the important factors of risering method. It is sometimes said that thin neck is more effective than thick neck to control the shrinkage. In this experiment cylindrical ductile iron castings were made to find the effect of size of neck on shrinkage formation. On the condition that the diameter of casting is 45 mm and the diameter of riser is 60 mm, the optimum area of cross section of neck is 15 × 20 mm, and the optimum length is 15 mm. Longer or shorter necks are less effective. Thicker or thinner necks are also less effective.抄録全体を表示PDF形式でダウンロード (586K) -
斎藤 和夫, 市村 恒人, 川野 豊, 三田 好明1993 年 65 巻 1 号 p. 36-40
発行日: 1993/01/25
公開日: 2011/06/22
ジャーナル フリーIt has been reported that the high toughness of ADI was due to the martensite formation at intersection of twins created by the strain in retaind austenite. As the martensite transformation at twin intersection may relate to strain rate, the effect of the strain rate on the mechanical properties of unalloyed ADI was examined in this work. Specimens were austempered at 573 K or 648 K after austenitizing at 1173 K. The strain rate was changed in 7 stages from 1.67 × 10-2 mm/s to 8.33 × 10-1 mm/s. These experimental results are as follows. (1) The tensile strength is not affected by the change of strain rate under the austempered treatments. (2) The elongation slightly increases in strain rate of 8.33 × 10-1 mm/s in case of austempered at 573 K, and clearly increases above the 3.33 × 10-1 mm/s in austempered at 648 K. (3) In the case of 573 K and 648 K austempered treatments, the retained austenite contents are about 18 % and 36 %, and after stress induced these decrease about 20 % and 30 % respectively. However no change of retained austenite contents appeares with the increase in strain rate. And very fine martensites appear in strained retain austenite. (4) In spite of some increase in elongation, tensile strength doesn't change with the increase in strain rate under this experimental condition. This reason is presumed that in the case of rapid strain rate, elongation may only increase because simple parallel twin deformation occured prior to martensite transformation at twin intersection. However, this interesting expermental result should be continued to study further.抄録全体を表示PDF形式でダウンロード (673K)
技術報告
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呉 漢宗, 内田 敏夫, 安斎 浩一, 新山 英輔1993 年 65 巻 1 号 p. 41-45
発行日: 1993/01/25
公開日: 2015/01/21
ジャーナル フリーHeat transfer coefficient was measured for water cooling of die casting dies by fountain-type cooling. A model die was heated in a furnace while cooling. Heat transfer coefficients at the inner surface of the cooling hole were determined by adjusting the calculated temperature distribution to the measured steady state distribution. Heat transfer coefficient of the fountain-type cooling depended on water flow rate and the range of the value was roughly equal to that of the simple straight pipe. The value was at its maximum near the exit of the inner pipe and decreased in both forward and backward directions. Cooling efficiency was particularly reduced near the bottom of the cooling hole due to stagnation. To avoid this, the distance between the inner pipe exit and the hole bottom should be less than twice of the hole diameter. To avoid the lowered cooling efficiency in the backward direction from the exit, turbulence promoters, e. g. rings around the inner pipe, were found effective.抄録全体を表示PDF形式でダウンロード (2328K) -
木村 博彦, 山中 英之, 木村 智昭1993 年 65 巻 1 号 p. 46-52
発行日: 1993/01/25
公開日: 2015/01/21
ジャーナル フリーPDF形式でダウンロード (3222K)
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