Vol. 8 No. 4 CONTENTS
Special issue on Special Issue on Materials Evaluation by X-ray and Neutron Diffractions
Regular Articles
Special issue on Special Issue on Materials Evaluation by X-ray and Neutron Diffractions (Vol.8 No.4)
Preface (Vol.8 No.4)
Editorial |
Takao HANABUSA and Shinichi OHYA |
163 |
Review Paper (Vol.8 No.4)
Neutron Diffraction Measurements of Residual Stresses in Engineering Materials and Components |
 |
Keisuke TANAKA, Yoshiaki AKINIWA and Makoto HAYASHI |
165 |
General Papers (Vol.8 No.4)
The Optimization of the X-ray Stress Measurement Condition on Austenitic Stainless Tubes for Electirc Power Plants |
|
Takayuki KURIMURA and Takashi KONISHI |
175 |
Modeling and Simulation of the Ψ Assembly X-ray Stress Measurement Using PSD as Detector |
|
Toru GOTO |
181 |
Effect of Plasma Protection Net on Crystal Orientation and Residual Stress in Sputtered Gallium Nitride Films |
|
Kazuya KUSAKA, Kouhei FURUTANI, Takuya KIKUMA, Takao HANABUSA and Kikuo TOMINAGA |
187 |
Preventive Effect of Shot Peening on Stress Corrosion Cracking |
|
Shinobu OKIDO, ToshihikoYOSHIMURA, Kunio ENOMOTO, Hideyo SAITO, Ren MORINAKA and Tetsuya ISHIKAWA |
193 |
X-Ray Evaluation of Pulse-Plated Crack-Free Cr Layer |
|
Yuichi KOBAYASHI, Jun-ichi NAGASAWA, Kazuo WATANABE, Toshihiko SASAKI and Yukio HIROSE |
199 |
Mechanism of Magnetic Domain Refinement on Grain-Oriented Silicon Steel by Laser Irradiation |
|
Hiroshi SUZUKI, Koichi AKITA, Hiroshi MISAWA and Muneyuki IMAFUKU |
207 |
Effect of Polarization on Deformation and Fracture of Tetragonal PZT |
|
Kaori SHIRAKIHARA, Keisuke TANAKA and Yoshiaki AKINIWA |
213 |
Regular Articles (Vol.8 No.4)
General Papers (Vol.8 No.4)
Regularity of Strain Distribution in Short-Fiber/Whisker Reinforced Composites |
|
Xiaoyu LIU, Wei WU and Naigang LIANG |
219 |
Estimation of Delayed Failure Life of Alumina Ceramic Components Subjected to Thermal Stress during Practical Service |
|
Nagatoshi OKABE, Mitsuyoshi TSUTSUMI, Masashi TANIGUCHI and Mikio ABE |
225 |
Effect of Al Ion Implantation and Hydrogen Absorption on Shape Memory Properties of Ti-Ni Alloy |
|
Teruo ASAOKA |
231 |
Changes in the Barrier Properties to Gaseous H2S Accompanying by Elongational and Bending Deformations Imposed on Silicate Deposited Nylon 6 Films |
|
Motoo KAWASAKI, Tadakazu TSUKAMOTO, Yoshiharu KIMURA, Tatsuo IWASAKI and Hideki YAMANE |
237 |
Evaluation of Sorption Behavior of Heavy Oil into Exfoliated Graphite by Wicking Test |
|
Yoko NISHI, Guangze DAI, Norio IWASHITA, Yoshihiro SAWADA and Michio INAGAKI |
243 |
Nickel-Catalyzed Carbonization of Lignocresol to Produce Crystallized Carbon Usable for Electromagnetic Shielding |
|
Xiao-Shui WANG, Tsutomu SUZUKI, Masamitsu FUNAOKA, Yoshihiko MITSUOKA, Tetsuo YAMADA and Shuji HOSOYA |
249 |
Vol.8 No.4 ABSTRACT
Neutron Diffraction Measurements of Residual Stresses in Engineering Materials and Components
Keisuke TANAKA, Yoshiaki AKINIWA and Makoto HAYASHI
Abstract:The neutron diffraction method provides a powerful nondestructive method to measure the loading and residual stresses in the interior of the materials and has been applied to the determination of the residual stress distribution in various engineering structures such as welded and brazed joints. The neutron method also gives useful information on the microscopic stress or the intergranular stress induced in single and multiphase materials by plastic deformation and fatigue. The method is also available for the determination of texture and phase transformation inside the materials. The present paper reviews the fundamentals for stress measurements and the latest applications of the neutron diffraction method in the field of materials science and engineering. Several directions of future developments of the neutron method are suggested.
Key Words:Neutron diffraction, Residual stress, Diffraction elastic constant, Plastic forming, Welded structure, Coating, Composites, Fatigue damage
The Optimization of the X-ray Stress Measurement Condition on Austenitic Stainless Tubes for Electirc Power Plants
Takayuki KURIMURA and Takashi KONISHI
Abstract:Optimization of the rapid X-ray stress measurement method and its condition on large grain
austenitic tube steel using a Ka line has been investigated. X-ray residual stress measurements were conducted using several Ka lines on several surface conditions of large grain austenitic tube steel.
Using the Vka line, the measurement time can be reduced to one third compared to the CrKb line. For a rapid measurement, a superimposing procedure of the X-ray diffraction profile from different incident beam angles (superimpose oscillation method) was also employed chieving a similar effect to that of incident beam oscillation. The best measurement condition was discussed using the above superimpose oscillation method that is an effective method for material with a large grain size.
Key Words:X-ray stress measurement, Ka line, Austenitic stainless steel, Incident beam oscillation
Modeling and Simulation of the Ψ Assembly X-ray Stress Measurement Using PSD as Detector
Toru GOTO
Abstract:Recently, the position-sensitive detector (PSD) has been becoming popular for X-ray stress measurement. However, little information is available regarding the effects of systematic errors, including mis-setting of specimen and misalignment of collimator and detector, on the stress measurement. Many factors, such as stress and X-ray broadening of the specimen, X-ray focus size, dimensions of collimator and the PSD, and goniometer radius, are complicatedly related to the effects of the systematic errors. In this paper, a model of the pusai assembly (the side inclination method) X-ray stress measurement using PSD as the detector is presented, which enables us to simulate the stress measurement under various
conditions of systematic errors.
Key Words:X-ray stress measurement, Pusai assembly, Position-sensitive detector,Systematic error, Stress error
Effect of Plasma Protection Net on Crystal Orientation and Residual Stress in Sputtered Gallium Nitride Films
Kazuya KUSAKA, Kouhei FURUTANI, Takuya KIKUMA, Takao HANABUSA and Kikuo TOMINAGA
Abstract:X-ray diffraction was carried out in order to investigate crystal orientation and residual stress in gallium nitride (GaN) films deposited on a fused quartz substrate by radio frequency (RF) planar magnetron sputtering with a net to protect against plasma exposure. GaN films were deposited at constant gas pressure, constant input power, and various substrate temperatures. The following results were obtained: (1) GaN film of good crystal orientation can be deposited by RF sputtering; (2) in all films deposited at high substrate temperature, the c-axes of GaN crystals were oriented normal to the substrate surface; (3) crystal orientation was good in films deposited at high substrate temperature Ts > 573 K,
but film deposited at Ts = 873 K peeled from the substrate; (4) good crystal orientation was attained in films deposited by sputtering with the fine mesh to protect against plasma exposure; (5) compressive residual stress was found in film deposited at low Ts below 573 K; (6) compressive residual stress was found in films deposited by RF sputtering with the
plasma protection net.
Key Words:Gallium nitride film, Radio frequency sputtering, Residual stress, Crystal orientation, Plasma protection net, X-ray diffraction
Preventive Effect of Shot Peening on Stress Corrosion Cracking
Shinobu OKIDO, ToshihikoYOSHIMURA, Kunio ENOMOTO, Hideyo SAITO, Ren MORINAKA and Tetsuya ISHIKAWA
Abstract:The effect of shot peening (SP) on stress corrosion cracking (SCC) prevention was evaluated from the viewpoints of crack initiation and propagation. It was found that the residual stress in a Type-304 stainless-steel specimen is changed?from tensile of 300 Mpa to compressive of ?800 Mpa?by shot peening, and the effective SP depth is 0.35 mm. It was also found that the crack initiation and propagation were prevented by shot peening. The mechanism by which the shot peening prevents these phenomena is explained according to the theory of superposition and loading history. That is, the prevention of crack initiation and propagation results from the fact that the compressive residual stress caused by SP decreases the applied load on the crack surface and prevents rupturing of the oxide film on the surface. Moreover, the effects of SCC prevention were shown to be valid when cyclic loading is applied after peening.
Key Words:Stress corrosion cracking, Shot peening, Residual stress , Crack initiation, Crack propagation, Stress relaxiation
X-Ray Evaluation of Pulse-Plated Crack-Free Cr Layer
Yuichi KOBAYASHI, Jun-ichi NAGASAWA, Kazuo WATANABE, Toshihiko SASAKI and Yukio HIROSE
Abstract:Several crack-free Cr plating processes using pulse-current electrolysis have been proposed for improving corrosion resistance. However, industrial applications of crack-free Cr platings are very few since these Cr layers are subjected to tensile residual stress and easily form macrocracks after plating operations, particularly at temperatures higher than 373K. The
residual stress of crack-free Cr layers deposited by pulse-current electrolysis was evaluated by the X-ray diffraction method. With changing pulse conditions, various residual stresses were measured. The specimen in which initial compressive residual stress of the Cr layer exceeded -150MPa did not form macrocracks after holding at 473K for 2h, and showed a high corrosion resistance without rusting even after a 700h neutral salt spray test (NSST). The amount of change in the residual stress as a result of heat treatment correlated with the integral breadth of the diffraction profile, and became smaller and more stable with heat treatment as the integral breadth became narrower.
Key Words:X-ray stress measurement, Pulse current electrolysis, Crack-free Cr layer, Residual
stress, Integral breadth
Mechanism of Magnetic Domain Refinement on Grain-Oriented Silicon Steel by Laser Irradiation
Hiroshi SUZUKI, Koichi AKITA, Hiroshi MISAWA and Muneyuki IMAFUKU
Abstract:The residual stress distributions near the laser-irradiated line in a crystal grain of an electrical steel sheet were measured by the X-ray stress measurement method for a single crystal, in order to clarify the mechanism of the magnetic domain refinement which can be applied to reduce the core losses. A specimen containing only one grain was cut from a grain-oriented silicon steel, and was irradiated with a laser. The distributions of the residual stresses and those of the half value width (HVW) of the diffraction profile, which indicates the plastic strain level near the laser- irradiated line, were measured before and after the stress-relief annealing, and their magnetic domain structures were observed. Before annealing, the HVW was increased near the laser-irradiated line, since the local plastic deformation was induced by the peening effect of the laser irradiation and the process of melting, cooling, and contraction after the laser irradiation. Therefore, the tensile residual stresses were induced near the laser-irradiated line. Next, the magnetic domains were refined more than they were before the laser irradiation. After annealing, the HVW was constant at the initial value, and the residual stresses were relieved. The magnetic domain then returned to its original width. Therefore, it was confirmed that the magnetic domain was refined due to the residual stress induced by the laser irradiation.
Key Words:Grain-oriented silicon steel, Laser irradiation, Core loss, Magnetic domain, Residual stress
Effect of Polarization on Deformation and Fracture of Tetragonal PZT
Kaori SHIRAKIHARA, Keisuke TANAKA and Yoshiaki AKINIWA
Abstract:
Key Words:
Regularity of Strain Distribution in Short-Fiber/Whisker Reinforced Composites
Xiaoyu LIU, Wei WU and Naigang LIANG
Abstract:Based on studies on the strain distribution in short-fiber/whisker reinforced metal matrix composites, a deformation characteristic parameter, λ is defined as a ratio of root-mean-square strain of the reinforcers identically oriented to the macro-linear strain along the same direction. Quantitative relation between λ and microstructure parameters of composites is obtained. By using λ, the stiffness moduli of composites with arbitrary reinforcer orientation density function and under arbitrary loading condition are derived.
The upper-bound and lower-bound of the present prediction are the same as those from the equal-strain theory and equal-stress theory, respectively. The present theory provides a physical explanation and theoretical base for the present commonly-used empirical formulae. Compared with the microscopic mechanical theories, the present theory is competent for stiffness modulus prediction of practical engineering composites in accuracy and simplicity.
Key Words:Short-fiber/Whisker reinforced composite, Strain distribution, Stiffness prediction, Anisotropy
Estimation of Delayed Failure Life of Alumina Ceramic Components Subjected to Thermal Stress during Practical Service
Nagatoshi OKABE, Mitsuyoshi TSUTSUMI, Masashi TANIGUCHI and Mikio ABE
Abstract:Many guide parts of Al2O3 ceramics are used as mechanical components in the hot environment of textile machines.
Some guide parts are occasionally fractured via fatigue failure due to thermal stress in service. The analysis of thermal stress requires knowledge of the heat transfer coefficients between a ceramic guide and cold airflow, as well as of the hot environment in service, because a continuous string running at a high speed of 10m/s carries cold room-temperature air to the ditch bottom of guide parts in the hot environment. However, for the heat transfer coefficients in such a situation, there has been no example of practical direct measurement in the past. Therefore, the heat transfer coefficients were estimated using an inverse analysis method, in which suitable heat transfer coefficients were estimated through trial and error, considering the correspondence of the fracture mode and strength between analytical fracture and actual fracture in service. From the analytical results for the thermal stress using the estimated heat transfer coefficients, the cause of fracture of some ceramic guides was clarified through fracture mechanics of a surface crack in a thermal stress field.
The lifetime of ceramic guides was estimated probabilistically also from the viewpoint of fracture lives in long-term service.
Key Words:Thermal stress, Heat transfer coefficients, Stress intensity factor, Delayed failure, Practical service, Mechanical components
Effect of Al Ion Implantation and Hydrogen Absorption on Shape Memory Properties of Ti-Ni Alloy
Teruo ASAOKA
Abstract:Al ion implantation was carried out with the aim of suppressing the absorption of hydrogen from the environment into the Ti-Ni shape memory alloy. A 100 nm thick, high-density Al layer was formed at the surface by ion implantation. The initial stress of martensite phase accommodation did not change by ion implantation and hydrogen absorption. On the contrary, the deformation stress corresponding to a strain of 4% in the martensite phase and shape recovery stress changed by both ion implantation and hydrogen absorption. A low dose of implantationrevealed that hydrogen absorbed near the surface diffused further into the specimen. The specimen with a high dose of ion implantation lost its shape memory properties due to the compositional change indicated by the shift of transformation temperature. In all cases, ion implantation affected the shape memory properties irrespective of the presence or absence of hydrogen, although the ion implanted layer was limited in the vicinity of the surface.
Key Words:Al ion implantation, Surface modification, Hydrogen absorption, Shape memory properties, Ti-Ni alloy
Changes in the Barrier Properties to Gaseous H2S Accompanying by Elongational and Bending Deformations Imposed on Silicate Deposited Nylon 6 Films
Motoo KAWASAKI, Tadakazu TSUKAMOTO, Yoshiharu KIMURA, Tatsuo IWASAKI and Hideki YAMANE
Abstract:The changes in the barrier properties due to the damage imposed on the SiOx deposited nylon 6 films accompanying various deformations such as bending and elongation were examined by evaluating the corrosion rate of the copper plates by H2S kept in the pouches made of the damaged films. After application of elongational deformation of as high as 2 % or less, only slight corrosion of the copper plates, almost similar to those of the copper
plates kept in the pouches made of undeformed films, was observed. After application of elongational deformations of 3 % or more, the corrosion of the copper plates was more distinct and proceeded significantly with time.
Bending deformation given to the SiOx deposited nylon films also deteriorated the barrier property to H2S when the radius of curvature at the bent part was small. Comparison of the corrosion rates of the copper plates kept in the pouches made of films deformed in various ways and undeformed commercial films shows a clear relationship between the H2 permeation rate of the films and the corrosion rate of the copper plates by H2S.
Key Words:Barrier Property, H2S Gas, Silicate Deposited Nylon 6 film,Elongation, Bending
Evaluation of Sorption Behavior of Heavy Oil into Exfoliated Graphite by Wicking Test
Yoko NISHI, Guangze DAI, Norio IWASHITA, Yoshihiro SAWADA and Michio INAGAKI
Abstract:A wicking method technique to study the sorption behavior of heavy oil into exfoliated graphite packed in a glass column was developed. The weight increase of the exfoliated graphite column during the sorption process was continuously measured. It was found that the sorption speed depended on the viscosity of heavy oils. Sorption of the A-grade heavy oil with a low kinematic viscosity was a hundred times as quick as that of the C-grade oil with a high viscosity. Packed density of the exfoliated graphite in the column affected not only sorption speed but also the sorbed amount of heavy oil, because the size of opening spaces formed among the exfoliated graphite particles and the pore volume per unit weight of exfoliated graphite decreased with increasing the packed density. The exfoliated graphite column with the higher packed density showed quicker sorption of heavy oil. Exfoliated graphite with density of 7 kg/m3 showed the largest weight of sorbed oil per unit weight of the graphite. The weight of sorbed oil per unit weight of exfoliated graphite decreased with increasing the packed density. In the saturated weight of heavy oil sorbed into the column, however, the maximum value was found when the exfoliated graphite was slightly densified from 12 to 16 kg/m3.
Key Words:Heavy oil recovery, Sorption, Exfoliated graphite, Wicking test, Capillary phenomena
Nickel-Catalyzed Carbonization of Lignocresol to Produce Crystallized Carbon Usable for Electromagnetic Shielding
Xiao-Shui WANG, Tsutomu SUZUKI, Masamitsu FUNAOKA, Yoshihiko MITSUOKA, Tetsuo YAMADA and Shuji HOSOYA
Abstract:Lignocresol (LC), which is recovered from wood by adopting phase separation system with sulfuric acid/cresol, was carbonized at 900oC for 1 h after loading with nickel alone or both nickel and sodium, and the crystal structure of carbon and the electromagnetic shielding (EMS) capacity at 50-800 MHz were evaluated for the resulting char. For comparison, four other isolated lignins were subjected to the same treatment and measurement. LC char could produce crystallized carbon (T-component) markedly by co-loading of nickel 8-9 wt% and sodium 8-10 wt% to exceed a practical standard of EMS capacity, 30 dB at 800 MHz, although nickel alone was ineffective. The capacity of the LC char with both nickel and sodium was superior or comparable to those of the corresponding other lignin chars. Without nickel, LC char resulting from the unique structure gave less amorphous carbon with larger EMS capacity than other chars. These results showed that LC was suitable as raw lignin for converting into EMS material by nickel-catalyzed carbonization.
Key Words:Lignocresol, Lignin, Nickel-catalyzed carbonization, Crystallized carbon, Electromagnetic shielding