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Volume 60, Issue 11
November
Displaying 1-9 of 9 articles from this issue
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Paper
Paper
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Atsushi HIBINO, Osamu KOMAKI2013 Volume 60 Issue 11 Pages 441-450
Published: November 15, 2013
Released on J-STAGE: January 22, 2014
JOURNAL OPEN ACCESSABSTRACT
In order to improve the mechanical properties of TiAl intermetallic compound by combustion synthesis, it is also effective to synthesize composite Ti – Ni – Al intermetallic compound by the addition of Ni. However, in combustion synthesis of Ti – Ni – Al system, difficulty of reaction control of elemental Ti/Ni/Al mixed powder brought meltdown or poor sintering to the synthesized product. In this paper, by developing two-step combustion synthesis process, fabrication of Ti – Ni – Al intermetallic compound was examined. Namely, in 1st-step combustion synthesis, TiAl and Ni3Al compound powders were composed. In 2nd-step combustion synthesis, by mixing TiAl, Ni3Al, Ti, Ni, and Al powders, Ti – Ni – Al intermetallic compound was synthesized by the combustion synthesis reaction. By using the two-step combustion synthesis, dense Ti – Ni – Al intermetallic compound could be fabricated. The microstructure of the product consisted of about 20 µm crystal grain. From SEM – EDX analyses, it was found that the compound phases were TiNi2Al phase (τ4) and TiNiAl2 phase (τ2). Since Ti – Ni – Al intermatallic compound can be synthesized easily by the two-step combustion synthesis, development of future investigation of the ternary intermetallic compound material is expected.View full abstractDownload PDF (1325K)
Special Issue: Advances in Sintering Mechanism of Powders and Novel Sintering Technology
Summarization
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Akira KAWASAKI2013 Volume 60 Issue 11 Pages 452-
Published: November 15, 2013
Released on J-STAGE: January 22, 2014
JOURNAL OPEN ACCESSDownload PDF (134K)
Memorial Lecture of JSPM Award
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– Effect of Alloy Elements on Microstructure and Mechanical Properties of P/M High Strength Brass Alloy –Hisashi IMAI, Shunfeng LI, Yoshiharu KOSAKA, Katsuyoshi KONDOH2013 Volume 60 Issue 11 Pages 453-459
Published: November 15, 2013
Released on J-STAGE: January 22, 2014
JOURNAL OPEN ACCESSABSTRACT
In this study, the effects of additive alloying elements on microstructure and mechanical properties of Cu – 40 % Zn alloy prepared by powder metallurgy (P/M) process were investigated. Raw Cu – 40Zn – Cr – Ti – Fe – Sn brass powders, having a single beta phase, were made by water-atomization process. Grain size of brass powder was smaller with increasing the solid solution of alloying elements. The brass alloy powder billet consolidated by sintering at less than 873 K had high solid solution of alloying elements. P/M Cu – 40Zn – 0.8Cr0.3Fe0.6Sn0.6Ti extruded material at 773 K showed 751 MPa UTS, 582 MPa YS and, 17.0 % elongation. SEM – EDS, XRD and TEM analysis clarified this P/M high strength brass alloy was mainly strengthened by solid solution mechanism of the alloying elements such as Cr and Ti which had a low solid solubility limit in brass. Extruded material of P/M Cu – 40Zn – 0.8Cr0.3Fe0.6Sn0.6Ti with 1.0 mass% graphite particles had both high strength and suitable machinability by solid solution of alloying elements due to no formation of hard carbides.View full abstractDownload PDF (1523K)
Review
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Takayuki NAKAMOTO, Nobuhiko SHIRAKAWA, Haruyuki INUI2013 Volume 60 Issue 11 Pages 460-466
Published: November 15, 2013
Released on J-STAGE: January 22, 2014
JOURNAL OPEN ACCESSABSTRACT
Optimum conditions for laser irradiation to achieve fully dense high-carbon steel selective laser melting (SLM) specimens have been investigated as a function of carbon content in steel powders using steel powders with different carbon contents of 0.33 − 1.04 mass% C. Full densification is easily achieved by SLM processing for all high-carbon steel powders. The energy density during the SLM process necessary for full densification decreases as the carbon content increases from 400 J/mm3 for 0.33 and 0.49 mass% C to 267 J/mm3 for 0.76 and 1.04 mass% C, which is considered to be attributable to the increased wettability of molten Fe – C alloys on steel powders and sintered specimens for the higher carbon contents. Moreover, SLM specimens that are strong enough to be used as stamping dies are produced by plasma nitriding specimens that have been sintered from an alloyed steel powder, JIS-SCM430. After plasma nitriding, the surfaces of the specimens have a compound layer, the so-called “white layer”, composed of ε – Fe2−3N and γ’– Fe4N. The surface hardness of the specimens plasma nitrided at 773 K and 823 K are about 680 HV and 600 HV, respectively and are much higher than that of the original SLM specimens – about 330 HV –.View full abstractDownload PDF (1320K)
Paper
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Takanori MIMOTO, Shufeng LI, Junko UMEDA, Katsuyoshi KONDOH2013 Volume 60 Issue 11 Pages 467-474
Published: November 15, 2013
Released on J-STAGE: January 22, 2014
JOURNAL OPEN ACCESSABSTRACT
TiH2 raw powders were directly consolidated by cold pressing, sintering and hot extrusion to fabricate pure Ti materials. The residual hydrogen content depended on the sintering temperature, and showed a significant effect on α/β phase transformation during hot extrusion. When 0.33 mass% hydrogen was contained in the sintered compact, α→β phase transformation occurred completely at extrusion temperature of 1073 K, and resulted in the formation of <0001>α texture of the extruded Ti material. This texture was completely different from that of the conventional extruded Ti materials (<10 – 10>α texture) with very few contents of hydrogen. The former indicated extremely high tensile strength (σ) of 959 MPa and enough elongation (δ) of 27.6 % compared to P/M extruded pure Ti materials with σ = 634 MPa and δ = 29.9 %.View full abstractDownload PDF (1955K) -
Minoru KASAI, Atsushi HIBINO, Haruki YASHIRO2013 Volume 60 Issue 11 Pages 475-481
Published: November 15, 2013
Released on J-STAGE: January 22, 2014
JOURNAL OPEN ACCESSABSTRACT
In the fields of an eco-friendly automobile, an advanced industrial machine, and a precision electronic device, controlling of vibrational behavior of the sintering parts obtained from powder metallurgy is required. In this paper, the vibration behavior of porous material made by powder metallurgy is investigated by a FFT analyzer. Pure Cu powders (Average particle size: 36 µm, 89 µm) are used as initial substances. The powder is compressed by a metal die with 100～200 MPa, and a plate shaped Cu compact is made. Using a high vacuum furnace, the green compact is heated from room temperature with 10 ˚C/min, and is sintered at 700～1000 ˚C for 1 hour. By changing the powder particle size, the compaction pressure, and the sintering temperature, some kinds of sintered Cu porous plates which had various microstructures, varied porosity, and different mechanical properties are sintered. For the sintered Cu porous plate obtained, microstructure observation, tensile test and vibration test are performed.
The vibration behavior of the sintered Cu porous plates is analyzed from the frequency response function of the FFT analyzer. The damping coefficient of the sintered Cu porous plate depends on the porosity and the open pore ratio. The vibrational behavior of the sintered material is able to be easily measured by FFT analyzer.View full abstractDownload PDF (1070K) -
Atsushi HIBINO, Ryohei YAMAZAMI, Yutaro SHIRAISHI2013 Volume 60 Issue 11 Pages 482-489
Published: November 15, 2013
Released on J-STAGE: January 22, 2014
JOURNAL OPEN ACCESSABSTRACT
Gas release behavior of alloyed steel powder during sintering process was analyzed by gas chromatography. In our previous paper, gas release behaviors of Fe powder, Fe – 3 % Cr powder, Fe – 4 % Ni powder and Fe – Cr – Ni powder were investigated. From the investigation, it was found that Cr component in the alloyed steel powder reduced CO2 gas release, and that Ni component increased H2O gas release from the alloyed steel powder. However, since there were too few experimental data, it was lacking in reliability of the experimental result. Therefore, gas release behaviors of Fe powder, Fe – 1.5 % Cr powder, Fe – 2 % Ni powder and Fe – 1.5 % Mo powder were measured in this paper. The gas release behaviors of Fe – 1.5 % Cr powder, Fe – 2 % Ni powder and Fe – 1.5 % Mo powder were similar to them of Fe – 3 % Cr powder, Fe – 4 % Ni powder and Fe powder respectively. In Fe – 1.5 % Cr powder, the Cr component reduced CO2 gas release, and in Fe – 2 % Ni powder, the Ni component increased H2O gas release. Therefore, the effect of the alloy component against the gas release behavior was cleared from the present investigation. Additionally, thermodynamic analysis was attempted for the CO2 release behavior of Fe powder.View full abstractDownload PDF (1012K)
JSPM Announcements
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2013 Volume 60 Issue 11 Pages Pref11_1-
Published: November 15, 2013
Released on J-STAGE: January 22, 2014
JOURNAL OPEN ACCESSDownload PDF (900K)
Errata
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-Elements, AB Compounds, Fe- and Cu-based Compounds-Yukio MAKINO, Kazuyoshi YOSHIMURA2013 Volume 60 Issue 11 Pages 491-
Published: November 15, 2013
Released on J-STAGE: January 22, 2014
JOURNAL OPEN ACCESSErrata:
About the paper by Yukio Makino et al. published in Vol.59 No.12, December 2012 issue of the journal, an error in the sub title should be corrected.
p.665 English title
(Error) Relation between Critical Temperature and Pseudopotential Radi — Elements，AB Compounds，Fe-and Cu-based Compounds —
(Correct) Relation between Critical Temperature and Pseudopotential Radii — Elements，AB Compounds，Fe-and Cu-based Compounds —View full abstractDownload PDF (153K)
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