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Hiroshi ASANUMA, Genji HAKODA
Article type: Article
Pages
395-396
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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This paper describes fabrication of active composites working at higher temperatures without using polymer based materials. In this study, continuous SiC fiber reinforced aluminum composite was laminated with unreinforced aluminum plate by the interphase forming/bonding method using copper insert. The obtained material was curved during cooling form hot pressing temperature. Curvature of the composite at room temperature increased with increasing length of specimen, that is, length of the SiC reinforcement fiber in the experimental range up to 60mm. The composite at room temperature was actuated by heating, and its curvature decreased and became zero at the temperature of about 570K, which was decreased by reduction of length of the composite. This temperature and the curvature at room temperature after thermal cycle were reproducible. Continuous SiC fiber reinforced nickel active composite was also tried to be fabricated by the similar method. Curvature of the obtained material was also successfully changed as a function of temperarure up to higher than 800K.
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Toshio ISHII, Hiroshi ASANUMA
Article type: Article
Pages
397-398
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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This paper describes development of simple strain sensors to be embedded in aluminum and its composites. In this study, nickel wire and titanium wire were selected because they were easily covered with uniform oxide layers by oxidation in air and they wrought as insulators when they were embedded in aluminum matrix. Effects of diameter of wire and type of wire on sensitivity of strain measurement when tensile tested were investigated and the following results were obtained. (1) Sensitivity of strain measurement by NiO/Ni composite fiber embedded in aluminum matrix increased by decreasing its diameter. (2) TiO_2/Ti composite fiber could also be successfully embedded in aluminum plate by hot pressing in air without damage. Its sensitivity of strain measurement was twice as high as that of NiO/Ni fiber of the same diameter.
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Masahiro Hirano, Hideki Hosoda, Hiroaki Suzuki, Shuichi Miyazaki
Article type: Article
Pages
399-400
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Diaphragm type microactuators utilizing Ti-Ni thin films sputter-deposited on a Si wafer were fabricated by the photolithography method. The dynamic behavior of the actuators were characterized by measuring the movement of the actuators during heating and cooling. The temperature variation was achieved by sending or cutting off electric current alternatively. The displacement of the movement depended on the electric current, the switching ratio of the electric current and frequency of the actuation.
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Noboru SUGIMOTO, Tsuyoshi SAITO
Article type: Article
Pages
401-402
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Normality checking functions are essential for measuring systems to identify hazards of machinery or chemical plants. In this paper, logical relationship between the normality checking and the hazard detecting in safety confirmation systems is formulated and basic requirements of the measuring system are discussed. As an example satisfying those conditions, the structure of a dangerous gas detection system using gas-chromatography is shown.
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Yoshikazu MORIKAWA, Yoshikatsu ENOKIDA, Tomohiro NARUSE, Toshio HATTOR ...
Article type: Article
Pages
403-404
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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In many industrial machinery or power plant machinery, the accurate evaluation of mechanical behaviors of bolted joint structures are very important for the reliability improvements of these machinery. In this paper, sliding and deformation behaviors of two bolt joints with thin spacers under transverse loading conditions are studied analytically and experimentally.
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Tomoyuki HAMADA, Hiroaki KASAI, Takayuki MATSUI, Atsushi SANEKANE
Article type: Article
Pages
405-406
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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The optimum seismic shutdown level for elevators, which will reduce the number of shutdowns occurring without seismic damage, is estimated. This estimation uses maintenance record data of elevators for obtaining seismic-shutdown-ratio curves and damage-occurrence criterion, which are then used to determine the shutdown-level margin. It was thus revealed that the newly revised shutdown level (150cm/s^2) for rope elevators has a large margin to the damage occurrence criterion and the shutdown level for hydraulic elevators can be raised to 75cm/s^2,which corresponds to the safety factor comparable to rope elevators. It is concluded that seventy percent of shutdowns can be eliminated by adopting these new shutdown levels.
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Takabumi FUKUDA, Masayuki TANABE, Hisaji SHIMIZU
Article type: Article
Pages
407-408
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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This paper concerns on detection and classification of machinery conditions by the application of patter recognition. In previous paper, the Kullback discrimination information with AR model has been applied to detect the pre-assumed conditions of a compressor, (1) normal, (2) suction filter choking, (3) suction valve spring failure, (4) piston ring wear, (5) suction valve failure and combination of (2)-(5). This method could classify these conditions. In this paper, this method is compared with another similar pattern recognition method, correlation function method, from the point of anti-noise characteristics.
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Kiyotsugu SAKA
Article type: Article
Pages
409-410
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Kazuyoshi KATOH, Hiroshi TOKISUE
Article type: Article
Pages
411-412
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Turning and facing machinability was performed on the 2017 aluminum alloy by measuring cutting resistance and surface roughness. In case of cutting speed which changes every moment, cutting resistance were decreased with increasing of cutting speed. And they were decreasing with increasing of side rake angle. In case of using tool with side rake angle of 18°, tangential force by turning was higher than that of facing. If cutting speed constant, cutting resistance were decreasing with increasing of cutting speed. In case of cutting speed changed, surface roughness by turning were decreasing with increasing of cutting speed but they showed constant value of surface roughness by facing.
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Tsutomu MURAI, Susumu MIYAMOTO, Yoshinari OKI, Shinichi MATSUOKA, Seii ...
Article type: Article
Pages
413-414
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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This paper describes the effect of dies angles on the extudabirity of AZ31B magnesium alloy ranging from 30 to 90 degrees. It became clear that it can not be obtained a good surface appearance with the 90 degrees die because of the surface cracks. But extrusion pressure and mechanical property of the shapes are almost equal on these die semi-angles.
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Yasuo SUGA, Shinichiro KAWAMURA, Koich OGAWA
Article type: Article
Pages
415-416
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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In this study, the estimation of temperature distribution of weld during friction welding of different diameters of S45C carbon steels, in which complicated phenomena occur at the weld interface, using the Finite Element Method (FEM) is discussed. In calculation, the consideration of heat loss by the generation and growth of flash is very important. The system constructed can change the heat input distribution depending on the temperature distribution of weld interface, and can estimate the heat loss due to the burn-off. Then the effectiveness of this system was confirmed by comparing calculations and experimental results.
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Teruyuki SEKIYA, Kazuyoshi KATOH, Hiroshi TOKISUE
Article type: Article
Pages
417-418
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Drilling machinability of pure titanium was investigated by using a high speed steel drill. The drilling experiment was conducted changing helix angle under a dry condition. Out of roundness was worsening with increasing helix angle and it improved with increase cutting speed. Amount of eccentricity was worsening with increasing helix angle. Out of roundness and amount of eccentricity were independent of feed. The diameter of entrance was larger than diameter of exit.
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Hidenobu OHTA, Akihito MATSUMURO, Yutaka TAKAHASHI
Article type: Article
Pages
419-420
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Hidenobu OHTA, Akihito MATSUMURO, Katsuya NAGAKUBO, Yutaka TAKAHASHI
Article type: Article
Pages
421-422
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Akihisa Mori, Akihito Matsumuro, Hidenobu Ohta
Article type: Article
Pages
423-424
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Masatosi SAITOU, Tomohiro MAKABE
Article type: Article
Pages
425-426
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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We have studied the kinetic surface roughening of nickel films electrodeposited on ITO glasses at alow current density using atomic force microscopy, electron and X-ray diffraction. The AFM images of the nickel films exhibited the scaling relations represented by the growth exponent β=078±0.03 and the roughness exponent α=0.96±0.04 that is in good agreement with the prediction by the diffusion-driven growth model. Electron and X-ray diffraction revealed a preferred growth orientation of the electrodeposited nickel films, which gives an explanation for the growth exponent β greater than 1/2.
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Hiroyuki HASEGAWA, JIANBIN Ju, Keisuke HORIGAMI, Yasuo SUGA
Article type: Article
Pages
427-428
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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In automatic butt welding of relatively thin plates, it is important to control welding condition in order to obtain a sound full penetration weld. Recently, it was reported that there is an intimate relationship between the oscillation of molten pool and penetration. Accordingly, a control system of welding condition in TIG are welding according to the frequency of molten pool was constructed. But it is difficult to detect the molten pool oscillation, if width of the molten pool is under 5mm. Therefore, pulse-shielding gas oscillating method that is more sensitive in detecting oscillation than pulse current oscillating was proposed. In this study, detection system of the peculiar frequency of the molten pool and control system of the welding condition were constructed in TIG are welding with pulse-shielding gas oscillating method.
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Yasuo SUGA, Daisuke TAKENAKA, Yuto HIBIKIYA
Article type: Article
Pages
429-430
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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This paper deals with sensing of weld pool condition from reverse side and control of penetration in fixed pipe welding. In order to realize full-automatic welding of fixed pipes under high pressure atmosphere, it is important to control the back bead width properly. Accordingly, a method controlling the back bead width from the reverse side is proposed. As it is difficult to measure the back bead width directly, it is estimated by analyzing the molten pool shape and the dimensions. Furthermore, Neural Network is applied so as to estimate the relations among the parameters of the weld pool shape, welding conditions and the penetration of weld. The back bead width is controlled by controlling the welding current estimated from the output of the Neural Network. As the result of welding control experiments. The effectiveness of the proposed system in the penetration control of fixed pipes is verified.
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Yoichi AKAGAMI, Koichi Asari, Toshio MIYAZKI, Toyohisa FUJITA, Noritug ...
Article type: Article
Pages
431-432
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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The particle dispersion type ER fluid has been already synthesized to be assisted efficiently precision polishing under A.C field at low frequencies. Here observed the phenomenon of gathering particles at polishing area using visual experimental apparatus. Therefore we have tested the dense particle concentration type ER fluid and obtained the items to design for efficiently polishing fluid about viscosity of solvent and particle concentration 100cSt and 30 wt.% over respectively.
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Masahiro SHINZAWA, Hideki KYOGOKU, Shinichiro KOMATSU, Hideki NAKAYAMA
Article type: Article
Pages
433-434
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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The effects of microstructural factors and sintering conditions on mechanical properties of the sintered SUS304L stainless steel compacts made by powder injection molding were investigated. The specimen were made of water-atomized (W) and gas-atomized (G) powders which were blended with a polyamide binder system. The tensile strength and elongation of the sintered compacts were equivalent to those of the wrought steel. The tensile strength and elongation of the compact sintered at 1673 K were 520MPa and 57% respectively. The grain growth in the W-powder compact and the G-powder compact was governed by the cubic low. The restrictive force of precipitates in the W-powder compact at the grain boundary was stronger than that of pores in the G powder compact. The proof stress of the compact followed the Hall-Pecth relationship.
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Daisuke MIZUNO, Takashi MATSUOKA, Kazuhiko SAKAGUTI, Hideki KYOGOKU
Article type: Article
Pages
435-436
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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The fatigue properties of 304L stainless steel specimens made by metal injection molding with gas atomized powder and water atomized powder were investigated. The experiment was carried out under the tension-tension cyclic loading. The fatigue strength of gas atomized compact was higher than that of water atomized one. And, the residual strength test for water atomized compact specimen was also carried out. Then, the residual strength was increasing at the initial stage on the fatigue testing. However, it is clear that the residual strength was decreasing with increasing the number of cycles. Fatigue fracture regions and static fracture regions were clearly observed for the gas atomized compact, on the other hand, the fatigue fracture region could not be obviously appeared on the case of the water atomized compact.
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Hiroyuki JINUSHI, Hideki KYOGOKU, Hideki NAKAYAMA
Article type: Article
Pages
437-438
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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The effects of C addition and debinding temperature on sintering behavior of Cr-Mo steel compacts shaped by metal injection molding were investigated to carry out the control of C content of sintered compacts. The specimens were made of SCM415 steel powder and additional C powder with polyamide binder. The compacts were debound in air at various temperatures and were sintered in argon gas at 1623K for 7.2ks. The obtained results showed that the reaction M_xO+C→xM+CO (M=Metal element) is dominant for reducing oxides during sintering process and the excess or shortage of C reducing oxides in compact determines the C content which strongly affects the density and mechanical properties of sintered compacts.
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Mitsuhiro MATSUDA, Hideshi MIURA
Article type: Article
Pages
439-440
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Sintered Ni alloy steels produced by Metal Injection Molding (MIM) process showed the high density and high static fracture strength than that of the same composition materials produced by the conventional Powder Metallurgy (P/M). However, there are very few reports about the dynamic fracture characteristics of Fe-Ni-C MIM steels at the present time. In this study, the behavior of impact fracture characteristics for the sintered Ni alloy steels produced by MIM process varying Ni content from 2 to 8 mass% were investigated. The impact strength were improved with increasing Ni content, especially the improvement was remarkable in the low testing temperature.
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Akihito OTSUKA, Masakazu ACHIKITA
Article type: Article
Pages
441-442
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Metal Injection Molding (MIM) process is applied to various materials such as stainless steels, low alloy steels, titanium alloys and so on. However in case of low alloy steels including low carbon contents it is difficult to control carbon contents (0.13∿0.18mass%) and attain higher density (above 95%). In this study we used fine mixed powders for attaining higher density and added carbon for controlling appropriate carbon contents. The results were as followed. (1) MIM sintered body of High density (96%) was obtained by using fine mixed powders including 0.04mass% carbon and its carbon content was 0.14mass%. (2) Maximum tensile and yield strength was obtained at 623K tempering temperature. (3) Vickers hardness curve fro surface was comparable with that of wrought material.
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Shunsuke Takeguchi, Takao Kishitani
Article type: Article
Pages
443-444
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Kazuo Isonishi
Article type: Article
Pages
445-446
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Mechanical alloyed powder milled for fully time mainly consists of metastable and/or unstable phases. Phases of these powders would be changed to be stable phases at elevated temperature. When the composition of milled powder corresponds to intermaetallic composition, distinct exothermic reaction will also occur at the same time. Two types of MA powder having the composition of Ti-37.5mol%Si used in this investigation, amorphous powder and (Ti+Si) lamellar structure powder. This investigation discusses the relationship between phase formation from meta/unstable phase to stable phase and densification properties during pressure sintering by using vacuum hot pressing technique. It is concluded that the phase formation from meta/unstable phase enhances the densification under the applied pressure, because of the excessive deformation associated with nucleation of newly phases.
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Toshitsugu KODAKA, Eiji YUASA
Article type: Article
Pages
447-448
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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The powder of chromium, iron and titanium were mixed with aluminum powder 5and/or 10mol%each. MA (mechanical alloying) has carried out for those powders in the region of milling time of 1.8-216ks. Obtained powder were studied by the methods of X-ray diffraction, Vickers hardness measurement and differential scanning calorimeter. As a result, it can be understood that chromium is solid-soluted in alunium phase by MA for 72ks. Inaddition, the crystalline size of α-Al phase decreases while hardness is increases as milling time increases. That relationship between crystalline size and hardness satisfies the Hall-Petch relation. Furthermore, Al-Fe and Al-Ti alloys has shown a similar tendency, as well.
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Tsuyoshi YUKI, Eiji YUASA, Yuichi ODAKA
Article type: Article
Pages
449-450
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Powder mixtures of Al-25mol%Ni and Al-40mol%Ni were mechanically alloyed for various milling times. In the powder mechanically alloyed for over 18ks. AlNi (β) phases have formed. The crystallite size of AlNi (β) phases have decreased with increase of milling time, and it became to about 40mm. The Al-40mol%Ni alloy powders mechanically alloyed for 180ks were consolidated by the hot-pressing under various conditions. Density of the compact is increased with increase of hot pressing load. In addition, compression testes have been carried out to investigate mechanical properties of those compacts at room and high temperatures, and then structural change of the compact during the hot pressing.
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Yun LU, Mitsuji HIROHASHI, Takahiro TSUCHIDA, Yasuhiro SOMA
Article type: Article
Pages
451-452
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Reaction sintering using hot-press in vacuum, argon gas and atmosphere was carried out in order to increase the density of the Ni-Al system intermetallic compound. The density, microhardness and reactants of the compacts were examined and discussed. The results showed that high density Ni-Al system intermetallic compound can be obtained by reaction sintering using hot-press. The Ni-Al system intermetallic compound can be produced by reaction sintering using hot-press in argon gas and atmosphere.
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Susumu SHIMA, Hidetoshi KOTERA, Yasushi YAMAMOTO
Article type: Article
Pages
453-454
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Simulation of powder compaction in closed die is carried out by the elastic-plastic FEM. The study is focused to investigate the effect of toll kinematics in die-compaction on density variation in a multi-stepped part. Based on the simulation results, it is shown that there is an appropriate tool kinematics that provides a small variation in density in the obtained compact. It is also shown by the simulation that a slip crack-like defect can occur depending on the tool kinematics.
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Sudumu SHIMA, Hidetoshi KOTERA, Yuuki SAKAMOTO
Article type: Article
Pages
455-456
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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An elastic-plastic FEM is developed to study fundamental features of rubber isostatic pressing (RIP) with a view to performing a net-shape process. It is thus shown that the properties of the rubber, in particular Poisson's ratio, give a great influence on the shape and density distribution in obtained compacts. The thickness of the rubber mold is also influential, the thicker the mold, the nearer the shape of compact is to the cavity shape. With a view to net-shape forming, an optimization scheme is also developed for determining the cavity shape for a desired shape of compact.
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Sumio FUJIMURA, Hitoshi TAKAGI, Hiroaki ITO, Hisakazu TOMINO, Yoshihit ...
Article type: Article
Pages
457-458
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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This paper deals with powder forming behavior of ground chips which discharged while ball bearings are manufacturing. The ground chips are investigated whether it is possible to use as P/M raw material used for mechinary parts. Two kind of sintering processes were used, that is Spark Plasma Sintering (SPS) and Vacuum Sintering (VS). The density for SPS materials was higher than that for VS materials. In addition, the bending strength for SPS materials with high density was extremely high. We can conclude that the SPS is a suitable powder forming method for ground chips.
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Hiroyuki Y. SUZUKI, Kenji SHINOZAKI, Hidenori KUROKI
Article type: Article
Pages
459-460
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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A high purity (of 99.99%) and fine (of 0.2 μm) alumina powder is dispersed in the ion-exchanged water and compacted by High-speed Centrifugal Compaction Process (HCP) and Pressure Casting (PC). Green compacts are pre-sintered at 1073 K for 3.6 ks and subsequently sliced into 500 μm thick disks. The disk are immersed in diiodmethane and observed by optical microscopy with transmission light to reveal internal structures of green compacts. Although HCP and PC green compacts show almost the same green densities and sintered densities, only PC compacts contain many residual Bubbles remaining as huge pores after pre-sintering. The residual bubbles in PC compacts become larger as the viscosity of slip increases. The de bubbling effect of HCP is far greater than that of vacuum de-bubbling, whereas its efficiency is also affected by the viscosity of eh slip. In HCP, the bubbles can be removed more effectively by using a slip with low viscosity.
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Kazuhiro MATSUGI, Yubo WANG, Hisakazu OKUMURA, Tomei HATAYAMA, Osamu Y ...
Article type: Article
Pages
461-462
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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The spark sintering technique is used for the sintering of 7075-rapidly solidified aluminum powder. The various microstructures are obtained by changing of process parameters, such as the maximum sintering temperature, sintering period and cooling method after sintering. The solid soluted amount of main alloying elements increases as the maximum temperature and period increase in the sintering. Various materials sintered at 873K for 10 to 2400 sec show the same behaviour of age-hardening. On the other hand, plastic strain of material increases as the holding period in the sintering at 873K increases, and that of materials sinterd at 873K for 1200sec is same as that of solution treated materials. It is suggested on the basis of value of the plastic strain obtained from tensile test that materials sintered under the conditions of the long exposure and higher temperatures show largely solid-soluted amount of main alloying elements and promotion of sintering.
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Tadanobu INOUE, Shiro TORIZUKA, Kotobu NAGAI
Article type: Article
Pages
463-464
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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The plastic strain in a specimen introduced by compression with a pair of anvils is evaluated using a three-dimensional dynamic finite element analysis. The stress-strain relations depending on strain rate and temperature are used in the analysis. The contact condition between the anvil and the specimen is determined from the experimental result from an identically deformed screw set in the specimen. The plastic strain introduced by uni-direction compression is compared with that by bi-direction compression simultaneously or non-simultaneously given from different directions. The non-simultaneous bi-direction deformation is proposed as a method to introduce a large plastic strain widely in the specimen. The bi-direction deformation can be developed as a technique to obtain ultra-fine grain steels for thick plates.
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Shiro TORIZUKA, Tadanobu INOUE, Kotobu NAGAI
Article type: Article
Pages
465-466
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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A multi-direction deformation thermo-mechanical treatment simulator was designed and developed to verify the prediction by the FE-anaylsis on the effect of bi-direction deformation which can introduce a large plastic strain widely in a specimen. Using this simulator, both uni-direction and bi-direction deformations were performed for a 0.16%C-0.4%Si-1.4%Mn steel with a prior austenite grain size of 300μm at 1073K at a strain rate of 1/s. The microstructure was composed of grain boundary polygonal ferrite and intragranular Widmanstatten ferrite in the uni-direction deformation specimen. On the other hand, the half thickness of the specimen was composed of fine polygonal ferrite in the bi-direction deformation specimen. This region corresponds well to the region having a plastic strain more than 2. The uniform formation of the fine polygonal ferrite due to the wide introduction of the large plastic strain was verified for the bi-direction deformation.
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Akira AZUSHIMA, Koshiro AOKI, Yousuke ASADA, Yoichiro KIMURA
Article type: Article
Pages
467-468
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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In order to create high strength materials, the metal forming with large strain is one of the available forming processes. The authors have developed the repeated shear deformation process with side-pressure under high hydrostatic pressure. After 10 times of shear deformation process, a tensile strength reached at about 1000MPa. But the elongation of material was considerably small. In this study, the ultra low carbon steels deformed up to 10 times by shear deformation process were annealed, and the properties were investigated. The elongation of material was increased with decreasing Vickers hardness and tensile strength.
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Akira AZUSHIMA, Koshiro AOKI, Yousuke ASADA, Youichirou KIMURO
Article type: Article
Pages
469-470
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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In order to develop the high strength materials, the forming process with large strain is one of available processes. The authors have developed the repeated shear deformation process with side-pressure under high hydrostatic pressure. In this study, the 0.25%, 0.15% and 0.05% Carbon-Steels are deformed by shear deformation process, and the property of materials are investigated. The 0.25% Carbon-Steel specimen was pressed without rotation (route A) or with rotation of 90° after one pass (route C). Vickers hardness and tensile strength increased about twice as large as those of as-received materials after first process. After first process, the texture from bottom of specimen developed at center in the plane and 6 poles around it.
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Yoshitaka ADACHI, Toshiro TOMIDA, Shigeharu HINOTANI, Masaaki FUJIOKA, ...
Article type: Article
Pages
471-472
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Ultra-refinement of α grains via transformation from heavily deformed-largely supercooled γ and dynamic recrystallization accelerated by heavy deformation is studied.
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Norikazu MATSUKURA, Masahiro NOMURA, Kouichi MAKII, Shigenobu NANBA
Article type: Article
Pages
473-474
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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It has been tried to refine ferrite grain size due to ferrite recrystallization and ferrite transformation from deformed austenite applying large strain in (γ+α) dual-phase region. In this study, the microstructure before deformation was optimized for grain refinement. It is found that both low deformation temperature (750∿800℃) and relatively low α fraction are effective for grain size refinement in this process, then 1.1μm grained material was obtained by increasing carbon content for reducing α fraction and lowering deformation temperature.
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Koshiro AOKI, Yasuyuki KATAOKA, Akira AZUSHIMA
Article type: Article
Pages
475-476
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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In order to develop the high strength materials, the forming process with large strain is one of available processes. The authors have developed the repeated shear deformation process with side pressure under high hydrostatic pressure. In this study, the aluminum base materials (pure aluminum and Al-Mg alloy) are deformed by shear deformation process with or without side pressure, and the effect of side pressure for properties of those materials are investigated. Vickers hardness had no effect on the side pressure, however, the side pressure influenced bulk form of workpiece and deformation texture. After 10 times shear deformation process with side pressure, fine grain structures were obtained. Tensile strength increased about twice as those of as-received materials after 10 times deformation process.
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Yoshihiro SAITO, Hiroshi UTSUNOMIYA, Hiroyuki SUZUKI, Tetsuo SAKAI
Article type: Article
Pages
477-478
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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ECAE (Equal Channel Angular Extrusion) process was successfully used as an intense straining process to obtain ultra-fine grained metals. However, the process is essentially discontinuous and the productivity is quite low for industrial purposes. The authors have proposed a novel continuous shear deformation process called 'conshearing' to solve this problem. This process can be also used as a texture-control method of long coiled strips by shear textures. Commercial purity aluminum annealed strips (1100-O) are successfully consheared at room temperature. The whole process is repeated up to four passes. The changes in structure, texture and mechanical properties in conshearing process and in subsequent annealing are investigated. It is found that the r-value, i.e. deep drawability is remarkably improved.
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M. OTSUKA, H. HAYASHI, T. ITOU, T. UEKI
Article type: Article
Pages
479-480
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Toshio HAGA
Article type: Article
Pages
481-482
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Aluminum alloy strips were cast using a melt drag twin roll caster (MDTRC). Casting speed (roll speed) of MDTRC was much higher than that of conventional type twin roll caster for aluminum alloy. Microstructure of the strip became fine as the roll speed became high. Tensile strength and elongation of Al-6%Si strip cast using MDTRC was better than that of ingots cast by mold casting.
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Hideto SUZUKI, Souichiro NISHINO, Kunio OHYA
Article type: Article
Pages
483-484
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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From the viewpoint of the hybridization of experiment and simulation, we examined the new technique on shape freezing property evaluation of the automotive steel board with various strength levels. The simple V-bending test was carried out and some effects (e.g. microstructure, radius of curvature and bending angle) on shape freezing property were evaluated individually. The total amount of the elastic strain became useful evaluation guideline of the shape freezing property that is not influenced in the kind of material and forming condition. By this evaluation system which hybridized simple bending test and simple FEM simulation, the prediction of spring back error will become possible in practical manufacturing.
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Weimin LIN, Hitoshi OHMORI, Yutaka YAMAGATA, Sei Moriyasu, Akitake MAK ...
Article type: Article
Pages
485-486
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Libo ZHOU, Hiroshi EDA, Jun SHIMIZU, Hirotami NAKANO, Ryo KONDO
Article type: Article
Pages
487-488
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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This research project has successfully developed a one-stop manufacturing system, using fixed abrasive grinding wheel instead of free sully, to provide a totally integrated environment for φ300mm silicon wafer manufacturing to achieve the surface integrity equal to or better than the current lapping, etching and polishing processes. The key component developed for this system is the giant magnetostrictive actuator, which is used to precisely position the grinding head against the workpiece for non-defect grinding. With the closed-loop feedback control, the actuator is able to move half a ton of payload at the resolution of 6.25Å. The first trail test has shown the result of surface roughness Ra less than 1nm and global flatness less than 0.2μm.
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Tsunemoto KURIYAGAWA, Yinbiao GUO, Katsuo SYOJI
Article type: Article
Pages
489-490
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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This paper deals with a new type of radial pattern structure wheel for better surface roughness and flatness of workpiece in ultra-precision plane honing. To analyze the machining principle of honing and distinguish the influence on machining accuracy by dynamic pressure of coolant in different conditions, it is obvious that radial pattern wheel has higher machining flatness and lower surface roughness than this of spiral pattern wheel. Further, to set different machining parameters and carry on the honing experiment with two kinds of pattern structure wheels and workpiece, a good experiment data has been obtained. By this result, the best pattern structure of wheel further can be carried out.
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Akira MOCHIZUKI, Gorou Satou, Yutaka Nagasawa
Article type: Article
Pages
491-492
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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An efficient mechanism which consists of a heat roller and a pressure roller for flattening crumpled paper was developed. Mechanical properties of papers with some crumples or folds were measured experimentally, and the paper was heated by a hot wind under tension. Folds in the paper were optically observed. And it was found that applying heat make the paper stronger. Furthermore it was found that there makes another folds in the paper unless stretching the paper in an orthogonal. direction to paper feeding direction. Mechanical model for flattening crumpled paper was proposed. The numerical result was good agreement with experimental result.
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Hitomi YAMAGUCHI, Takeo SHINMURA
Article type: Article
Pages
493-494
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Vibratory burnishing processes produce smoothly finished surfaces on metal works by the relative motion between the work and the hardened steel tools in vibratory burnishing equipment. This process has the advantage of increasing the fatigue strength of the work surface by the tools' impingement on the work. As this process is a mass finishing process, it is difficult to achieve the precise control of the processing force as well as the tools' action on the work. This study proposes a new magnetic field assisted burnishing process using magnetically controlled motion of the tools and work. This paper presents the processing principle and a developed burnishing machine. The experiments, involved the burnishing of stainless steel and aluminum alloy bars, show the feasibility of process to achieve smoothly finished surface, work hardening, and the impartment of the residual compressive stress on the work surfaces.
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