巻号一覧
45 巻, 7 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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毛利 猛, 小橋 真, 長 隆郎, 金武 直幸1995 年 45 巻 7 号 p. 379-384
発行日: 1995/07/30
公開日: 2008/10/30
ジャーナル フリーSiCsp, TiCsp, ZrCsp and TaCsp composites were fabricated by a melt stirring process and the effect of species of carbides on mechanical properties were measured. The strength of SiCsp/pure aluminum composite is higher than those of TiCsp, ZrCsp and TaCsp/pure aluminum composites. The strength and the elongation of SiCsp/Al-3mass%Mg alloy composite are lower than those of base-metal, because of the formation of reaction products and/or the clustering of particulates. On the other hand, in the case of TaCsp composites, the reaction products can not be detected by either SEM or X-ray analysis. Isothermal treatments at 573K are found to have little effect on the strength of TiCsp, ZrCsp and TaCsp composites, although the strength of SiCsp composites decreases at an early stage of the treatment. However, the strength of composites fabricated by PM technology is unaffected by the isothermal treatments. ICP emission spectrometric analysis of decomposed metallic elements content in matrix indicates that the effect of isothermal treatment time on the decomposition of each composite is weak. TaCsp composites show the stable property of strength even after isothermal treatments at 803K, though this temperature is not practically used for this material.抄録全体を表示PDF形式でダウンロード (2392K) -
才川 清二, 中井 清之, 杉浦 泰夫, 神尾 彰彦1995 年 45 巻 7 号 p. 385-390
発行日: 1995/07/30
公開日: 2008/10/30
ジャーナル フリーMechanical properties and microstructures of various Al-Li-Mg alloy castings containing small amount of Zr and/or Ti were investigated. The δ (AlLi) phase was observed to crystallize in the dendrite-cell gaps as well as on the grain boundaries. Microsegregation of Mg also occured in the solidified castings. The β (Al3Zr) or Al-Zr-Ti compounds crystallize during solidification and remain even after solid solution treatment at 803K for 36ks. The grain sizes of Al- 2.5%Li-2%Mg alloy castings become finer by the addition of 0.15%Zr and 0.12%Ti compared with each addition of 0.15%Zr or 0.12%Ti. The age hardning is accelerated by the addition of 0.15%Zr. In an Al-2.5%Li-2%Mg-0.15% Zr-0.12%Ti alloy casting poured into a metallic mold and aged at 453K for 36ks, ultimate tensile strength, Young's modulus and density were 417MPa, 80GPa and was 2.52g/cm3, respectively. Its specific strength and modulus are higher by 50.3 and 13.9% than those of the conventional AC4C-T6 casting.抄録全体を表示PDF形式でダウンロード (1825K) -
李 斗勉, 李 俊瑞, 李 智煥1995 年 45 巻 7 号 p. 391-396
発行日: 1995/07/30
公開日: 2008/10/30
ジャーナル フリーAZ91D magnesium alloy machined chips were extruded at various extrusion conditions such as extrusion ratio and die angle. The mechanical properties and microstructure of the extruded chips were studied in order to find optimum extrusion parameters. The cold-pressed chips were hot extruded at the temperature of 573K and the ram speed of 130mm/min. The extrusion ratio was in the range 10:1 to 40:1 and the die angles (2θ) was 60°to 180°.The microstructure of the extruded chips showed fine equiaxed grains (<20μm) due to dynamic recrystallization during hot extrusion. Also, the mechanical properties of the extruded chips were compared with those of the as-received ingot and extruded ingot. The mechanical properties of the extruded chips incresed with increasing extrusion ratio. The tensile strength and elongation of the chips at the extrusion ratio 25:1 were 340MPa and 10%, respectively. These values were approx- imately the same as those of the extruded ingot. In contrast, the mechanical properties of the chips were decreased as die angle (2θ) increased. We believe that good extrusion properties of AZ91D magnesium alloy machined chips can be obtained at extrusion ratio of >25:1 and die angle of 60°.抄録全体を表示PDF形式でダウンロード (1862K) -
小橋 真, 大浦 知樹, 長 隆郎1995 年 45 巻 7 号 p. 397-402
発行日: 1995/07/30
公開日: 2008/10/30
ジャーナル フリーAluminum matrix composites have been fabricated with the help of an in situ reaction between titanium, boron nitride and aluminum in nitrogen or argon gas atmosphere. Microstructures of specimens have been observed to identify the size and the shape of the in situ formed particles. The spontaneous infiltration of the powder phase with molten aluminum have completed at 1473K in both nitrogen and argon atmosphere. The temperature of the specimen increases rapidly just after the infiltration due to a reaction between molten aluminum and titanium powder. The formation of TiB2 and AIN particles occured gradually subsequent to the infiltration of molten aluminum. The differential thermal analysis has revealed that titanium in liquid phase has been required to initiate the in situ reaciton. The molten aluminum infiltrated into the powder compact at a relatively high rate (3.4mm/s). The higher hardness is achieved at the bottom part of the specimen. The microscopic observation has correspondingly revealed that the higher volume fraction of TiB2 and AIN is obtained at the bottom part.抄録全体を表示PDF形式でダウンロード (1162K) -
中山 栄浩, 鷹合 徹也, 金 大洲1995 年 45 巻 7 号 p. 403-408
発行日: 1995/07/30
公開日: 2008/10/30
ジャーナル フリーEffects of the cold working and isothermal heating on the precipitation of the β'-phase were investigated for 5083 and Al-5mass%Mg binary alloys. Tensile properties were also examined mainly related with the precipitation of the β'-phase, change in solute atom concentration and serrated yielding behavior. The obtained results are as follows. (1) The pronounced precipitaiton of the β'-phase took place at about 453K for the 5083 and Al-5mass%Mg alloys. (2) No effcts of the β'-phase on the yield stress were observed. (3) The elongation to fracture decreased caused by the precipitation of the β'-phase. (4) The serrated yielding changed in accordance with the isothermal heating and precipitation of the β'-phase.抄録全体を表示PDF形式でダウンロード (871K) -
山内 利夫, 西田 義則1995 年 45 巻 7 号 p. 409-414
発行日: 1995/07/30
公開日: 2008/10/30
ジャーナル フリーThe infiltration of molten metal into fibrous preforms using the squeeze casting technique was investigated by the calculation based on the analytical equations obtained in the previous papers to elucidate the infiltration phenomena. The preform top surface pressure and the location of infiltration front are obtained by these equations when the infiltration speed is given. The calculation was performed on the preform top surface pressure and the compressive deformation of preforms as parameters of the initial volume fraction of fibers, infiltration speed and pre-heat temperature. The radius of a fiber is the most effective factor on the preform top surface pressure among various factors. The deformation of the preform starts when the preform top surface pressure exceeds the compressive strength of the preform. Therefore, if the preform top surface pressure does not exceed the compressive strength, homogeneous composites are expected to be obtained wihtout any deformation. On the contrary, the gradiently distributed fiber composites are possibly produced by controlling the infiltration speed.抄録全体を表示PDF形式でダウンロード (650K) -
相浦 直, 浅野 和彦1995 年 45 巻 7 号 p. 415-428
発行日: 1995/07/30
公開日: 2008/10/30
ジャーナル フリーPDF形式でダウンロード (4833K) -
奥田 浩司1995 年 45 巻 7 号 p. 429-430
発行日: 1995/07/30
公開日: 2008/10/30
ジャーナル フリーPDF形式でダウンロード (296K) -
1995 年 45 巻 7 号 p. 431-433
発行日: 1995/07/30
公開日: 2008/10/30
ジャーナル フリーPDF形式でダウンロード (337K)
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