巻号一覧
52 巻, 12 号
選択された号の論文の8件中1～8を表示しています
- |<
- <
- 1
- >
- >|
研究論文
-
高橋 平四郎, 上井 久雄2002 年 52 巻 12 号 p. 575-579
発行日: 2002年
公開日: 2007/03/30
ジャーナル フリーMetal matrix composites (MMC) have been produced by various methods such as molten metal infiltration, powder metallurgy, melt stirring, hot pressure welding and so forth, depending on their applications. Pressureless metal infiltration process (PRIMEXTM Process) makes it possible that high volume fraction MMC with less particle segregation are inexpensively produced. MMC with alumina particle volume fraction of 37 vol% produced by pressureless metal infiltration exhibit superior physical and mechanical properties such as thermal resistance and wear resistance. As a result of performance evaluation on the MMC rotor, its wear is small along with good friction coefficient stability. Hence, there has come out a possibility of putting the MMC rotor into practical uses.抄録全体を表示PDF形式でダウンロード (466K) -
竹上 弘彰, 篠田 剛2002 年 52 巻 12 号 p. 580-585
発行日: 2002年
公開日: 2007/03/30
ジャーナル フリーIn the conventional friction welding, it is difficult to match phases at the particular position of a rotation side and a fixed side, because the rotating spindle does not exactly control the stopping position. Development of positioning control friction welding meets to be solved such difficulties as stop at the specified position during braking. This positioning control friction welding was achieved installing servo motor positioning system. The positioning control was examined for the friction welding of an aluminum alloy 6061. The positioning control was satisfactorily performed with a sufficient accuracy. Severe metal flow was observed in the vicinity of weld interface during positioning control. In tensile tests, the fracture occurred at the softened zone. The positioning control did not influence on the tensile strength of welded joints. The width of softened zone decreased with increase in brake timing and pressure. The joint welded under an optimum condition showed the maximum joint efficiency of 83.5%.抄録全体を表示PDF形式でダウンロード (416K) -
古田 昌伸, 成毛 康一郎, 柳沼 芳宏, 岡田 勝蔵, 清水 照三, 中山 栄浩2002 年 52 巻 12 号 p. 586-590
発行日: 2002年
公開日: 2007/03/30
ジャーナル フリーIn order to investigate effects of low temperature aging and reversion treatment on the serration of 6061 aluminum alloys, the reversion at from 423 to 853 K was conducted for the specimens in which the serration disappeared with the preliminary aging at 403 K. The measurements of electrical resistivity, DSC analysis and TEM micrographs showed that the solute atom concentration for the reversed specimens in which the serration generated again decreased remarkably due to formation of the precipitates, such as GP–zone, random-type, β″–phase, β′–phase and β–phase. Therefore, it was suggested that the disappearance of the serration was not affected by decrease of the solute atom concentration.抄録全体を表示PDF形式でダウンロード (468K) -
灰谷 直, 田村 洋介, 茂木 徹一, 河野 紀雄, 為広 博, 佐藤 英一郎2002 年 52 巻 12 号 p. 591-597
発行日: 2002年
公開日: 2007/03/30
ジャーナル フリーWe conducted this study to determine the solubility of iron in pure magnesium and Mg–Al molten alloys. Alloy ingots were prepared using high-purity magnesium (< 99.99%) and high-purity aluminum. These alloys were melted in a closed vessel with introducing a mixed gas of SF6 and CO2 to prevent oxidation or burning. Iron was added by a pure iron plate, which was immersed in the molten alloys (pure magnesium) at temperatures of 933 K (963 K) , 998 K and 1073 K. Molten alloys were held at the each temperature for 86.4 ks at maximum. A 5 ml specimen subjected to chemical analysis was collected from the top of melt by sucking through pre-heated titanium tube at given time intervals and then determined iron solubility. Following an equation was led as the experimental formula of iron solubility in pure magnesium (963~1073 K),
log NFesolu. = -7981/T + 3.931 (1)
where NFesolu. is the solubility of iron in the liquid phase (molar fraction), and T is the absolute temperature. This equation shows that iron solubility indicated by this experiment is smaller than those reported by any other researchers for temperatures up to 1073 K. We also led following equations, (2), (3) and (4), about Mg–3.2Al, Mg–6.5Al and Mg–9.0Al alloys (933~1073 K), respectively.
log NFesolu. = -4911/T + 0.723 (2)
log NFesolu. = -5115/T + 1.007 (3)
log NFesolu. = -4298/T + 0.263 (4)
The solubility of iron slightly increases with increasing aluminum concentration of alloy. We conjectured that, in this case, the solubility increases because the increase in Al concentration causes the activity coefficient of Al in the molten alloy to decrease.抄録全体を表示PDF形式でダウンロード (442K) -
藤井 秀紀, 菅又 信, 金子 純一, 久保田 正広2002 年 52 巻 12 号 p. 598-604
発行日: 2002年
公開日: 2007/03/30
ジャーナル フリーEffect of combined addition of Sc and Zr on structure and mechanical properties was investigated, in rapidly solidified Al–8%Fe, Al–4%Fe–4%Ni, Al–8%Mn and Al–8%Mn–2%Cr alloys containing combination of 0.2% Sc and 0.2% Zr. Rapid solidification was performed by gas atomizing the alloy melt and subsequent splat-quenching on a rotating water-cooled copper roll under an argon atmosphere. The rapidly solidified flakes were consolidated to the P/M materials by cold pressing, vacuum degassing and hot extrusion. TEM observation revealed that the matrix sub grain size was slightly smaller for the rapidly solidified P/M materials with Sc + Zr addition than for those without addition. Hardness of the P/M materials with Sc + Zr addition was higher than those without addition except for Al–8Mn–2Cr alloy. Tensile strength at room temperature was also higher for the materials with Sc + Zr addition except for Al–8Mn–2Cr alloy. However, increments in tensile strength due to Sc + Zr addition decreased with rising test temperature. Higher strength attained by Sc + Zr addition is considered mainly due to precipitation of Al3(Sc, Zr).抄録全体を表示PDF形式でダウンロード (589K) -
山田 銑一, 西川 聖, 大湊 顕一, 塚原 茂男2002 年 52 巻 12 号 p. 605-608
発行日: 2002年
公開日: 2007/03/30
ジャーナル フリーA SiCCVD fiber-reinforced TiAl matrix composites was fabricated by the sintering process. The compatibility of the strengthening fiber for the composites was investigated. The interfacial strength between the fiber and the matrix of the composites was improved by using the coated TiAl layer onto the SiCCVD fiber by the ion plating process. The interfacial shear strength was within the range of 160 MPa to 320 MPa. The coefficient of thermal expansion from 300 K to 1113 K was 11 × 10−6K−1 in the longitudinal direction, and was equivalent calculated values by the rule of mixture. The residual expansion was scarcely observed after the thermal cycling between 300 and 1113 K. However, the strength of extracted fiber from the composites was 3.1 GPa, decreased by 50% with the fiber strength of the as-received fiber.抄録全体を表示PDF形式でダウンロード (407K)
研究ノート
-
酒井 孝, 星合 壮大, 仲町 英治2002 年 52 巻 12 号 p. 609-610
発行日: 2002年
公開日: 2007/03/30
ジャーナル フリーPDF形式でダウンロード (343K)
解説
-
三輪 謙治2002 年 52 巻 12 号 p. 611-616
発行日: 2002年
公開日: 2007/03/30
ジャーナル フリーPDF形式でダウンロード (764K)
- |<
- <
- 1
- >
- >|