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Volume 59, Issue 5
May
Displaying 1-11 of 11 articles from this issue
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Paper
Paper
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Makoto Inoue, Yasuhiko Ohtani, Hideaki Shimada, Tsutomu Tomiyoshi, Hir ...2012 Volume 59 Issue 5 Pages 227-232
Published: May 15, 2012
Released on J-STAGE: July 24, 2012
JOURNAL OPEN ACCESSWe produced the diamond saw wire using the commercial lead-free solder as a fixing material of diamond abrasive particles, and sliced sapphire ingots into wafers with the saw wires.
The co-drawn brass coated piano wire was adopted as a core material. Electroless Ni-P coated diamond abrasive particles were employed to enhance adhesion between the solder and diamond abrasive particle. We developed the equipment that performs solder coating on wire, temporary fitting of diamond abrasive particles on wire, and final fixing, in one continuous operation. We were able to produce saw wires as long as around 2 km. By using these saw wires we succeeded in slicing a sapphire ingot of 50.8 mm diameter into 50 wafers at a time. However, the average thickness of the wafers tended to be thinner toward the winding side of the wire saw machine. The total thickness variation (TTV), the maximum surface waviness (WT) and the maximum surface roughness (RZ) tended to increase toward the winding side. During the slicing process of ingot, the load on the saw wire maximized when the wire had moved a considerable distance away from the center of the ingot.View full abstractDownload PDF (1947K) -
Hiroyuki Yamada, Mitsuya Hashii2012 Volume 59 Issue 5 Pages 233-238
Published: May 15, 2012
Released on J-STAGE: July 24, 2012
JOURNAL OPEN ACCESSThe h-BN/feldspar composite was sintered under ambient pressure at low temperatures in air. We studied the effect of the feldspar ratio on the composite strength. The h-BN powder contained 40 mass% B2O3. The feldspar was pre-melted and then milled before sintering. The melting point of the as-received feldspar was nearly 1500 K. The powder mixture of h-BN and the melt and milled feldspar was sintered at 1473 K. The bending strength of the composite improved with increasing the feldspar content above 30 vol%. The highest bending strength of 52 MPa was obtained for the 40 vol% feldspar contained composite. Therefore, the feldspar ratio needs more than 30 vol% for protecting h-BN from air during sintering.View full abstractDownload PDF (1745K) -
Makoto Kubota, Kengo Oka, Yoshitaka Nakamura, Hisato Yabuta, Kaoru Miu ...2012 Volume 59 Issue 5 Pages 239-245
Published: May 15, 2012
Released on J-STAGE: July 24, 2012
JOURNAL OPEN ACCESSThe compositional and thermal evolution of the crystal structure of the Bi1-xSmxFeO3 solid solution synthesized under a high pressure was investigated. Samples with 0.10≤×≤0.20 had an antipolar PbZrO3-type structure with a √2a×2√2a×4a perovskite superstructure at room temperature, while the sample with x=0.05 had a rhombohedral BiFeO3-type structure. Among them, the samples with 0.10≤x≤0.12 transformed from an antipolar PbZrO3-type structure to a polar BiFeO3-type structure and finally to a nonpolar GdFeO3-type structure on heating, which is similar to Zr-rich Pb(Zr,Ti)O3. On the other hand, the samples with 0.15≤x≤0.20 transformed directly to a nonpolar GdFeO3-type structure. The ferroelectric Curie temperature of BiFeO3 was markedly lowered by the Sm substitution.View full abstractDownload PDF (1207K)
Special Issue: The High Value-added Sintered Materials for Automobile and Response to Changing Environment
Summarization
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Toshiyasu Komatsu2012 Volume 59 Issue 5 Pages 248-
Published: 2012
Released on J-STAGE: July 24, 2012
JOURNAL OPEN ACCESSDownload PDF (134K)
Memorial Lecture of JSPM Award
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Chio Ishihara, Aya Hamano, Hirotake Hamamatsu, Tsuyoshi Akao2012 Volume 59 Issue 5 Pages 249-253
Published: May 15, 2012
Released on J-STAGE: July 24, 2012
JOURNAL OPEN ACCESSHitachi Powdered Metals and Denso developed new magnetic parts which consists of a high performance powder base soft magnetic core and a composite armature, and have been installed as magnetic parts in injectors for common rail systems meeting the EURO V regulation. The new powder base soft magnetic core for the stator, had achieved both high magnetic properties and outstanding machinability as a result of various improvements of the insulation property of the iron powder itself, optimization of the resin content and addition method, and optimization of the heat treatment method. On the other hand, the composite armature had achieved combined properties of good wear resistance, wrought steel, and excellent magnetic properties, sintered magnetic core, in a single device by using the sinter diffusion bonding method. These properties are more excellent than conventional parts. As a result, the performance of the injector has improved drastically.View full abstractDownload PDF (894K)
Paper
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Akira Yoshida, Akira Fujiki2012 Volume 59 Issue 5 Pages 254-257
Published: May 15, 2012
Released on J-STAGE: July 24, 2012
JOURNAL OPEN ACCESSA sintered part for automobile has been growing so far. Also, demands for higher strength of the materials are increasing. The compressive strength becomes more important in their requirement. However there are few detailed studies on compressive properties of sintering materials. Generally, it is thought that it was considered compression and tensile proof stress equal in strength of materials. It is important that compressive properties are measured precisely from the situation of the design. This study investigated the compression properties and simulated it about the stress behavior of sintering materials. In this examination, all sintered test pieces showed higher compressive proof strength than tensile proof strength. And the simulation, in elastic level, supported these results.View full abstractDownload PDF (926K) -
Kentaro Kudo, Terukazu Tokuoka, Hyungoo Kang, Toshiko Osada, Fujio Tsu ...2012 Volume 59 Issue 5 Pages 258-263
Published: May 15, 2012
Released on J-STAGE: July 24, 2012
JOURNAL OPEN ACCESSThis study aims to improve the fatigue strength of P/M gears and to substitute P/M gears for conventional wrought steel gears with reduced manufacturing costs. The 4600 series sintered alloy steels with mixed elemental powders show the mezzo-heterogeneous microstructure which consists of high-hard Ni rich areas and the surrounding martensitic structures. This mezzo-heterogeneous structure causes high strength to the products.
In this paper, we discuss the effects of Ni contents on the contact fatigue strength, and the effect of the pore size is also discussed for further strengthening. Especially, from the evaluation of the area of isolated pores in the densified surface layer after the rolling, it was found that the decrease of pore sizes is very important to improve the contact fatigue strength.View full abstractDownload PDF (1753K) -
Wan Sharuzi Wan Harun, Kinji Toda, Toshiko Osada, Hyungoo Kang, Fujio ...2012 Volume 59 Issue 5 Pages 264-271
Published: May 15, 2012
Released on J-STAGE: July 24, 2012
JOURNAL OPEN ACCESSIn order to develop the high-strength and high-hardness 440C stainless steel compacts, metal injection molding process was applied. In this study, we focused on the effect of sintering atmosphere, powder loading, and carbon addition on the mechanical properties and microstructures. The injection molded compacts were debound by solvent debinding followed by thermal debinding, and sintered at three sintering temperatures; 1240, 1250, and 1260°C in two atmospheres; pure hydrogen and partial vacuum. Three levels of powder loading 60, 63, and 64 vol% were prepared. Compacts were heat treated in order to enhance the performance. Although the sintered compacts in pure hydrogen obtained higher density, the performance offered by partial vacuum sintered compacts was found to be far better. Compact density of 98 % and hardness 63 HRC were achieved at powder loading of 63 vol% with additional 0.4 mass% C.View full abstractDownload PDF (3748K) -
Shinta Virdhian, Toshiko Osada, Takuma Sonoda, Hyungoo Kang, Fujio Tsu ...2012 Volume 59 Issue 5 Pages 272-277
Published: May 15, 2012
Released on J-STAGE: July 24, 2012
JOURNAL OPEN ACCESSThe use of titanium alloy component in automotive applications can lead to weight reduction and functional development such as life time, corrosion resistance as well. Metal Injection Molding (MIM) offers an efficient way to fabricate more complex shaped components of titanium alloys. However, MIM process is mostly applied for small parts. Fabrication of larger parts by MIM process is limited because much binder contain in MIM green parts makes it difficult to remove the binders without distortion or defects. The purpose of this study is to investigate the effects of processing parameters on the distortion of larger size specimen than usual MIM components. Specimens with different diameter and thickness were injection molded and especially the effect of thermal debinding conditions on the distortion was investigated in detail. Thick specimens needed slow thermal debinding heating rate to minimize the distortion. Moreover, distortion in MIM process was considered and it was clarified that the distortion after solvent debinding was bigger than other process, thus, the debinding condition was most important to control the distortion.View full abstractDownload PDF (1346K)
JSPM Announcements
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2012 Volume 59 Issue 5 Pages Pref5_1-
Published: May 15, 2012
Released on J-STAGE: July 24, 2012
JOURNAL OPEN ACCESSDownload PDF (33K)
Correction
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Osami Haruyama, Hiroyuki Sawada, Kazuhiro Yoshikawa, Ryuta Wada, Yoshi ...2012 Volume 59 Issue 5 Pages 279-
Published: May 15, 2012
Released on J-STAGE: July 24, 2012
JOURNAL OPEN ACCESSAbout the paper by Osami Haruyama et al. published in the February 2012 issue of the Journal, An English name of Mr. Wada had been left out. It should be corrected as the pdf file.View full abstractDownload PDF (105K)
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