Journal of the Japan Society of Powder and Powder Metallurgy Index

JAPAN'S powder metallurgy industry before World War II was essentially limited to the production of sintered hard alloys and materials for bulbs and tubes (W, Mo); the manufacture of other items was on a minor, experimental basis. After the war, however, the variety of powdermetallurgy products expanded rapidly to include bearings, friction materials, filters, machine parts, electrical contacts, collector brushes, and magnetic materials, until powder metallurgy was firmly established as a newly emerging industry. Fig. 1 gives the output (in tons weight) between 1957 and 1966, which has been rising steadily; the 1966 production, for instance, is about three times that in 1960. Today, as many as 80 major manufacturers throughout the country are concentrating on powder-metallurgy products, and together with others they are organized into such groups as the Japan Powder Metallurgy Parts Man,ufacturers Association, the Oemented Oarbide Tool Manufacturers Association, the Tungsten and Molybdenum Manufacturers Association, and the Kinwa-Kai (an association of magnetic-material makers). Among academic groups concerned with powder metallurgy is the Japan Powder and Powder Metallurgy Society; in addition, there are the Japan Institute of Metals, the Japan Society of Mechanical Engineers, and many others, eachidealing with powder-metallurgy questions from its own specialized viewpoint.

The Sendust alloy sheet (Fe-Al-Si system) is too hard to make thin sheet by rolling. The authors succeeded previously in the manufacturing of Sendust sheets by the powder-rolling. (The Journal of the Japan Society of Powder and Powder Metallurgy. Vol.14, No.1, 1967).The authors have tried to apply the new process of electric discharge sintering to the production of the Sendust alloy thin sheet and have succeeded. This process does not need both special atmosphere and furnace, and can produce thin sheets with free size and thickness. The sintering time in air is shorter as much as a few minutes.The characteristics of Sendust sheets produced by electric discharge sintering process were compared with those by powder rolling and vacuum sintering (powder metallurgy) and it has been cleared that the electric discharge sintering process is best.The optimum operating conditions in this process, such as discharging current, discharging time, and pressing pressure are very important to get the best sheets.In this report, the optimum operating condition to make the Sendust alloy thin sheet and, the measured characteristics, such as (μm, BHe, Br, B10), electric (ρ), and mechanical (hardness) properties are described.

It was a great honour for us to receive the 59th technical achievement award of Japan Society of Powder and Powder metallurgy (JSPM). We presented an overview of the metal injection moulding (MIM) technology development over 25 years of experience and future trends through our originally developed μ-MIM technology in the annual spring meeting of JSPM 2022, which are summarised in this paper.

The crystal structure of goethite (α-FeOOH) is orthorhombic. When precipitated from aqueous solution, goethite particles are fine and acicular. The fine size and acicular shape were essential to the evolution of high performance magnetic recording media such as audio tapes, video tapes and floppy discs. A series of studies on the preparation, the topochemical reaction and the characterization of iron oxyhydroxides and related oxides were one of the most important fields of the Japan Society of Powder and Powder Metallurgy in the 1960's and 1970's. They had contributed greately for the establishment and eventual spectacular development of magnetic recording industries. In this paper, the author wish to describe the past important milestones and personal expectations to the future of magnetic recording media.

Nano-structure of machinable silicon carbide: K. Suganuma, G. Sasaki, T. Fujita, M. Okumura, A. Nakazara, K. Niihara, Journal of the Japan Society of Powder and Powder Metallurgy, 38(3), pp. 374–377. (Apr 1991)

It is said that there are more than 40 MIM (Metal Injection Molding)-related companies in America. Aiming at the diffusion of MIM, 21 of these companies have formed and are members of an organization called MIMA (Metal Injection Molding Association). MIMA is one of the lower branches of MPIF (Metal Powder Industries Federation). Among MIMA member companies, there are MIM parts producers; powders, binders and feedstock suppliers; and MIM machine, debinding and sintering equipment suppliers. Last year, MIMA sent out a questionnaire to each of its member companies to inquire into the present conditions and future prospects of the MIM business, problems that hinder the diffusion of MIM, measures to be taken in order to achieve diffusion, etc. The results, which were totaled and released to member companies last year in October, indicated that most of the companies believed that a lack of educational campaigns aimed at part designers, who are MIM customers, was impeding MIM diffusion. At present, since it is also believed in Japan that the achievement of diffusion of MIM technology depends on the improvement of the understanding level of part designers, JSPM (Japan Society of Powder and Powder Metallurgy) and JPMA (Japan Powder Metallurgy Association) have begun to take measures aiming at MIM standardization and educational campaigns. We have the impression that the problems confronting MIM are the same around the world. The findings of this survey provide very interesting hints, and we believe that they will be a good reference for the development of MIM technology in our country.

The authors made a study on anti-corrosion treatment of iron base sintered structural parts, which were collected by the Japan Society of Powder and Powder Metallurgy, to be preserved as memorial samples for more than 100 years in the future. The requirements: 1) The anti-corrosion treatment should be effective for such a long period of time. 2) It should be possible to restore the samples to their original states physically and chemically if necessary during the preservation period.To find the most practical method of anti-corrosion treatment which suits the above requirements, the authors tried four kinds of anti-corrosion treatment, and obtained the results.The results: 1) Lacquer coating treatment proved to have the most effective anti-corrosion property among the four methods. 2) The lacquer coating did not cause any change in dimensions of the samples. 3) The lacquer filled the pores of the sample whose apparent density was less than 6.4 g/cm3, but was easily removed by extraction with a solvent such as acetone. 4) As for the sample having 7.0 g/cm3 apparent density, the lacquer did not penetrate through the pores into internal body of the sample even when the sample was dipped in lacquer.Based upon these results, the authors conclude that lacquer coating treatment is the most practical and suitable method for the above-mentioned purpose.

Recent research and development in metal forming in Japan

Machining performance for machinable ceramics. part 4 Wet cutting: E. Sentoku, M. Kumagai, Y. Fujimura, Journal of the Japan Society of Powder and Powder Metallurgy, 37(61), pp. 857–860. (25 Aug 1990)

Insects provide examples of many cunning stratagems to cope with the challenges of living in a world dominated by surface forces. Despite being the current masters of the land environment, they are at constant risk of being entrapped in liquids, which they prevent by having waxy and hairy surfaces. The problem is particularly acute in an enclosed space, such as a plant gall. Using secreted wax to efficiently parcel and transport their own excrement, aphids were able to solve this problem 200 Myr ago. Here, we report on the physical and physiological significance of this ingenious solution. The secreted powdery wax has three distinct roles: (i) it is hydrophobic, (ii) it creates a microscopically rough inner gall surface made of weakly compacted wax needles making the gall ultra-hydrophobic, and (iii) it coats the honeydew droplets converting them into liquid marbles, that can be rapidly and efficiently moved.

1. Introduction Yttrium-based superconductors（YBCO）are expected to be applied to transmission lines. But, it haven’t been widely used, one of the reason is that the substrate and the film formation are too expensive. In order to solve these problems, using stainless steel and an Electrophoretic Deposition method (EPD) method were adopted as a new system. However, it has been reported that using stainless steel has low oxidation resistance in high-temperature. It may cause to decrease the conduction performance as a wire［1］. On the other hand it is generally known that a film produced by EPD has low adhesion［2］. Therefore, we aimed to improve the above two points and create the new superconducting wires. 2. Experimental Producting the YBCO calcined powder is that mixture powder compounded by Y, Ba, and Cu in a 1:2:3 molar ratio was heated up to 880 ℃ during 10 h and then crushed. This process was performed three times in total. The powder was analyzed by X-ray diffraction (XRD).EPD method was used to form a YBCO film or a CeO2 film. A bath containing 10 g/l of YBCO or CeO2 powder and 0.1~0.2 g/l of I2 in 100 ml of acetone was stirred with a magnetic stirrer at a rotation speed of 500 rpm. Stainless steel sheet was used as both the electrodes. 600 V was applied during 30 seconds to produce the YBCO coatings on the cathode.Multilayer coatings were heated up to 950 ℃ during 6 h. After that it was analyzed by electron probe microanalysis (EPMA) to know the film thickness and diffusion behavior of elements for the interface between metal and oxide films. 3. Results and Discussion 3.1 Identification of YBCO calcine powder Calcined powder was analyzed by XRD. Obtained patterns almost match with the standard YBCO. Therefore the powder was identified as YBCO. 3.2 Examination of optimal EPD conditions At the first EPD, the YBCO film had peeled off and it was considered that hydrogen generated from the cathode is cause. This hydrogen is derived from hydrogen ions and it was generated by the catalytic action of enol type acetone and iodine present in the solution. Therefore, iodine concentration or enol type acetone concentration should be reduced than before in order to suppress the hydrogens. In this study, Iodine concentration was reduced from 0.2 g/l to 0.1 g/l. As a result of above conditions, the film didn’t peel off. From this, it was found that the cause of film peeling was generated hydrogen from the cathode, and 0.1 g/l iodine concentration is suitable for EPD when depositing the YBCO film. CeO2 film was also deposited in the same way. Fig.1 shows the electron micrograph of the CeO2 and YBCO layers on stainless steel sheet. Comparing each layers, although the CeO2 layer is densely deposited, but YBCO layer is not densely and many voids can be confirmed. It is considered that the particle size of YBCO is too large. Therefore, the size will be reduced in next time. 3.3 Examination of optimal substrate for main calcination Finally we analyzed interlayer mapping with EPMA between the stainless steel and the YBCO layers after heating up to 950 ℃. At this time, the existence of Fe was confirmed in the YBCO layer . YBCO is consisted of Y, Ba, Cu, and O. Including Fe is only stainless steel in the sample. From this, it is considered that Fe was diffused from the stainless steel layer to the YBCO layer by main calcination. While O was also detected in the stainless steel layer. However it isn’t included O. Therefore, it is considered that the diffusion of O occurred from the YBCO layer to the stainless steel layer, contrary to the diffusion of Fe. From this results, intermediate layer between the stainless steel and the YBCO layer is necessary to prevent the diffusion of Fe and O. References ［1］Tetsuo Kato, Katsushi Kusaka, Journal of the Japan Society of Powder and Powder Metallurgy, 27, 152 (1980)［2］Yoshinori Takayama, Nobuyuki Koura, Yasushi Idemoto, Hiroshi Yanagishita, Takashi Nakane, Masashi kawamura, Naotaka Tanabe, Journal of Ceramic Society of Japan, 107, 437 (1999)［3］Naotaka Minami, Nobuyuki Koura, Journal of the Surface Finishing Society of Japan, 43, 93 (1992)［4］A.K.Jha, N.Khare, Physica C, 469, 811 (2009) Figure 1

Certain types of ceramics have property that shows direct bonding to living bone tissue in vivo, and are referred to as bioactive materials. As a bioactive material, Bioglass® was discovered and developed in early 1970’s, inorganic glasses and materials based on them have been studied for bone substitutes for tissue repairing. In addition, elucidation of the mechanism by which they express their high biological affinity has been studied. The author has been interested in elucidating the mechanisms by which inorganic glasses show high biological affinity to bond to living bone, and has carried out fundamental research, as well as developing novel biomaterials based on the materials chemistry of glasses and ceramics. The science and technology of the bioactive glasses have made a significant contribution to the field of medicine. Whilst, 2022 has been designated as the International Year of Glass by the United Nations General Assembly, and events commemorating the science, technology and art associated with glass are being held around the world. As part of these events, a special feature on glass science and bioinspired materials was also held at the 2022 Spring Meeting of the Japan Society of Powder and Powder Metallurgy. Against this background, this paper describes the review of the author’s achievement awards, with a particular focus on glass and biomaterials, and the development of novel materials using bioinspired methods.

Heating mechanism of spark plasma sintering

透析を用いたコロイド状 CoAl 系層状複水酸化物ナノ粒子のサイズ制御 ………………………………………………………………………

Journal of the Japan Society of Powder and Powder Metallurgy Index