Curriculum Vitaes
Profile Information
- Affiliation
- Professor, Faculty of Science and Technology, Department of Engineering and Applied Sciences, Sophia University
- Degree
- 博士（工学）(工学院大学)
- Contact information
- hisamori
sophia.ac.jp - Researcher number
- 80317510
- J-GLOBAL ID
- 200901033684274272
- researchmap Member ID
- 1000293757
1999－ •Department of Engineering and Applied Science, Faculty of Science and Technology, Sophia Univers, Structional and functional biomaterials
1999－ •Department of Engineering and Applied Science, Faculty of Science and Technology, Sophia Univers, Environmental strength and furacture strenngth
In late years aging in my country lets affection of motor function such as osteoporosis by alteration such as a bone or articular cartilage, osteoarthritis of spine, osteoarthritis increase. Therefore be aimed for improvement of rich quality of life in health, and the living habits that took in sports are spreading broadly. However, with increase and aging of the action population, locomotorium injury such as a fracture, ligamentous breakdown, a cartilage injury increases again, too. A treatment of such a locomotorium disorder is one of a future medical problem. It is important to return attribute of locomotorium, configuration, a physical characteristic to an as possible original physiological state.
I study organism material replacing it in a bone, cartilage, band, arthrosis.
Study in particular medicine and science and technology studies from a confluent point of view.
(Subject of research)
JSPS Research for the Future Program
Fatigue characteristic evaluation of bio-titanium alloy
Effects of Mechanical Stress on Corrosion Resistance of Metallic Biomaterials
Evaluation of corrotion wear of Co-Cr alloy
Fatigue characteristic evaluation of beta-bio-titanium alloy
Influence of surface modification of bio metal material cause to organism
Fracture characteristic of bio-apatite ceramics
HAP Ceramics and HAP layer Formed on It's Surface in a Simulated Body Fluid
Preparation and bio-function evaluation of organic - inorganic hybrid bio composites
Construction of fatigue life improvement by surface treatment technology of titanium alloy for medical cares
Fatigue characteristics evaluation of β type titanium alloy having a notch
Fatigue characteristics evaluation of titanium alloy having a hole
Fatigue characteristics evaluation of SUS316L steel having a hole
Evaluation of Fatigue Characteristic of Ti-6Al-4V alloy shaped by Metal Powder Layered Method
Evaluation of fatigue properties of electron beamed and laser peened Ti-6Al-4V ELI alloy
Evaluation of 4-point Bending Fatigue Properties for Titanium Alloy Interlocking Nail
Effect of notch factor on torsional fatigue property of pure titanium and stainless steel
Evaluation of corrosion wear characteristics of biomedical Co-Cr alloy with a surface modification by ELID grinding
Evaluation of corrosion fatigue properties of pre-strained SUS316 and SUS304 steel
Effect of notches on fatigue properties of β titanium alloy
Proposal of evaluation method of adhesion strength of apatite films deposited on titanium alloy
Evaluation of fatigue characteristic of titanium alloy by shot-peening
Evaluating of corrosion wear resistance of Co-Cr alloy with designed surface by scratch
Investigation on Bad Fit of Locking Plate for Osteosynthesis
Evaluation of shear adhesion strength of titanium alloy coated with apatite thin film
Evaluation of bending fatigue properties of three-dimensional modeling titanium alloy subjected to surface modification process
Fabrication of artificial bone by reef-building coral and its characteristics
Evaluation of the torsional fatigue characteristics of the titanium alloy
Evaluation of fretting fatigue properties of titanium alloy
Evaluation of fatigue characteristic of Pure titanium alloy by shot-peening
Influence of simulated body fluid on the interface strength test of apatite coating titanium
Evaluation of the corrosion characteristics of the injection molding machine for SKD61 material
Fatigue strength of pure titanium which has been subjected to shot peening and its mechanism
Evaluation of load applied to the knee brace with a link mechanism
Evaluation of corrosive wear characteristics of the titanium-based metal material that has been subjected to surface design
Torsional fatigue characterization of surface-modified 3D modeling titanium alloy
Evaluation of the fatigue characteristics of the 3D layered manufacturing cobalt chromium alloy
Examination of the low profile of the spinal implant
Influence of microstructure on the fatigue properties of pure titanium employing severe plastic deformation for grain refinement.（
Evaluation of interfacial strength in thin-film coating material for medical use
Evaluation of the distal fixing strength of the intramedullary nail implant
Effect of strength due to laser marking to medical titanium material
Development of lower limb muscle strength measurement equipment
Evaluation of fretting fatigue characteristics of the different medical metal material
Evaluation of torsional fatigue characteristics of the β titanium alloy
(Proposed theme of joint or funded research)
Mechanics characteristics evaluation of medical material
Research Interests
29Research Areas
5Research History
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Apr, 2011 - Mar, 2012
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Oct, 2009 - Mar, 2010
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Sep, 2009 - Mar, 2010
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Apr, 2004 - Mar, 2009
Committee Memberships
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Jun, 2012 - Mar, 2014
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Apr, 2012 - Mar, 2014
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Aug, 2011 - Aug, 2013
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May, 2011 - May, 2013
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Oct, 2011 - Mar, 2012
Awards
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Mar, 2024
Papers
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PROGRESSES IN FRACTURE AND STRENGTH OF MATERIALS AND STRUCTURES, 1-4, 353-358 2219-2222, 2007Many kinds of materials are currently used as artificial bone substitutes. Hydroxyapatite (HA), the same as the main inorganic component of bone, is one of commonly used bio-ceramics and has excellent bioactivity and biocompatibility with hard tissues. However, it has problems as the bone filler or bone tissue-engineering scaffold due to low fracture toughness and low degradation rate. Recently, biodegradable materials for bone tissue have been developed to respond the requirement. Collagen, the same as the main organic component of bone, is biocompatible, biodegradable and promotes cell adhesion. A composites associated with HA is expected to have early osteoconduction and bone replacement ability, The present study was to fabricate bone-like composites consist of HA and collagen. Besides the ossiferous ability of the material in vivo is evaluated by using rabbits. Bone-like composites were successfully fabricated in this study, associating the collagen with HA. And the composites presented good osteoconductive and bone replacement potential.
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INTERNATIONAL JOURNAL OF MODERN PHYSICS B, 20(25-27) 3567-3572, Oct, 2006Many kinds of materials are currently used as artificial bone substitutes. Hydroxyapatite (HA), the same as the main inorganic component of bone, is one of commonly used bio-ceramics and has excellent bioactivity and biocompatibility with hard tissues. However, it has problems as the bone filler or bone tissue-engineering scaffold due to low fracture toughness and low degradation rate. Recently, biodegradable materials for bone tissue have been developed to respond the requirement. Collagen, the same as the main organic component of bone, is biocompatible, biodegradable and promotes cell adhesion. A composites associated with HA is expected to have early osteoconduction and bone replacement ability. The present study was to fabricate bone-like composites consist of HA and collagen. Besides the ossiferous ability of the material in vivo is evaluated by using rabbits. Bone-like composites were successfully fabricated in this study, associating the collagen with HA. And the composites presented good osteoconductive and bone replacement potential.
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Proceedings of the 1992 Annual Meeting of JSME/MMD, 2006 375-376, 2006
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The proceedings of the JSME annual meeting, 2006 459-460, 2006A bone-like composite that is composed of HA and collagen protein is reported to be bioactive and enhance bone growth. We have reported HA/Col. composite with precipitation method had been replaced by bone within 8 weeks. However, this composite is difficult to have sufficient mechanical property and formability. In this study, we have developed a composite that has improved formability by adding CMC gel to HA/Col. Mechanical property of this composite was evaluated by compressive strength test. Bioactivity was evaluated by soaking the composite in simulated body fluid. Results of measuring Ca^<2+> concentration in SBF after soaking indicate possibility of the bioactivity.
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The proceedings of the JSME annual meeting, 2006 439-440, 2006
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The proceedings of the JSME annual meeting, 2006 447-448, 2006The damage accumulation mechanism of Ti-6Al-4V alloy under simultaneous corrosion and fatigue was studied. Corrosion fatigue characteristics of the alloy were evaluated by using newly developed corrosion-fatigue system, with special attention to synergetic effects of corrosion and fatigue on repassivation behavior. Two types of corrosion fatigue tests, potentiostatic polarization test with fatigue damage and free corrosion potential measurement test with simulataneous application of fatigue were carried out. In corrosion fatigue test, the electric current density increased as the frequency of fatigue became higher. This is caused by surface corrosion reaction occurred with development of cracks. However, the number of cycle to failure did not change with the frequency of fatigue. Therefore, it was shown that fatigue does not influence the corrosion fatigue damage. It was also shown that titanium alloy was superior in corrosion resistance.
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The proceedings of the JSME annual meeting, 2006 449-450, 2006Two types of notched specimen of Ti-6Al-4V simulated screw configuration were prepared and cyclic fatigue test was performed in air to study fatigue property of titanium screw. Effect of heat-treatment on fatigue strength was also investigated. As a result, the specimen having a smaller notch diameter showed higher fatigue strength (N_f=10^7) than that of larger one. This result indicates that fatigue strength of notched screw can be organized with its stress concentration factor. Heat-treatment improves tensile and fatigue strength, but, endurance ratio (fatigue strength/tensile strength) become lower compared as-received materials, which supports the idea that heat-treatment affected strongly to the tensile strength not to the fatigue properties.
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Orthopaedic ceramic implants, 25 37-45, 2006
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Zairyo/Journal of the Society of Materials Science, Japan, 54(9) 940-945, Sep, 2005Titanium and its alloys are currently in use as implant materials for orthopaedic surgery. These alloys own outstanding corrosion resistance due to a dense and passive oxide film of a few nanometers' thickness on their surfaces. When these alloys are implanted in a living body, implanted surface material removal takes place because of mechanical wear and corrosion. Material degradation, due to simultaneous chemical and mechanical effects, limits long-term use of metallic biomaterials, such as stainless steels and titanium alloys. Thus, it is very important to investigate synergistic interaction between wear and corrosion. The aim of the present study is to clarify the damage accumulation mechanism of Ti-6Al-4V alloys under the simultaneous reaction of corrosion and wear. For this purpose, first, we developed a new tribocorrosion system and then we estimated corrosion wear characteristics of the alloys with special attention focused on the effects scratching rate on repassivation behavior. Two types of corrosion wear tests were carried out. One was a free corrosion potential measurement with simultaneous application of wear damage and the other was potentiostatic polarization testing with wear damage. To discuss the corrosion wear mechanism, the damaged surfaces were carefully observed by a scanning electron microscope. It was concluded that in corrosion wear environment, a transition of wear type from abrasive to adhesive was observed with an increase in the scratching rates. A higher scratching rate prevented regeneration of passive films on worn surfaces, resulting in the generation of relatively large corrosion pits and changes in wear form. These results suggested that the scratching rate was an important factor that affected the damage accumulation process.
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Zairyo/Journal of the Society of Materials Science, Japan, 54(7) 748-753, Jul, 2005A calcium phosphate compound (Hydroxyapatite) has similar composition and crystal structure to an organism bone. Except an absorbent calcium phosphate compound, the composition that resembled apatite and a deposit having configuration generate it on the surface of apatite ceramic in vivo. In other words apatite ceramics does an organism bone and direct bonding through an apatite deposit without causing negativism. Generally this function is named bioactivity. These functions can inhibit ionic elution, roosting, wear and fretting occurring in metal biomaterial, and be extremely important from a point of view to use in vivo. However, ceramics material is extremely inferior in mechanical properties in comparison with metal material. Therefore, an application to locus accompanied by high load is difficult. It is used as bone filling material such as shank or body of vertebra under the present conditions. In other words low load is applied to locus to be accompanied by. Therefore, static load than cyclic load is important when long-term use was considered. However, bioactivity ability of apatite ceramic material and relation of mechanical properties were not clarified. A fatigue characteristic in consideration of organism environment is particularly unclear. Furthermore, it is necessary to evaluate a fatigue characteristic and crack propagation behavior when microstructure changes by apatite and chemical reaction with body fluid. This study, a static fatigue characteristic of apatite ceramics in simulated body fluid environment was examined.
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Proceedings of the 1992 Annual Meeting of JSME/MMD, 2005 473-474, 2005
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Proceedings of the 1992 Annual Meeting of JSME/MMD, 2005 331-332, 2005
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The proceedings of the JSME annual meeting, 2005 449-450, 2005Compact tension specimen of hydroxyapatite ceramics (HAp) was prepared and cyclic corrosion fatigue test was performed in air, deionized water and simulated body fluid (SBF) to investigate the corrosion fatigue property of HAp. The environment where corrosion fatigue strength (N_f=10^7) was the lowest was deionized water environment. Subsequently was SBF environment, air environment. Corrosion fatigue fracture was observed with scanning electron microscope (SEM) to clarify this mechanism. As a result, as for the corrosion fatigue fracture configuration, fracture in transgranular was observed with high stress condition. On the other hand, intergranular fracture was observed with low stress condition. That is to say, it was stress dependence type with a short life time of case, and it was environment dependence type with a long life time of case. In addition, two corrosion fatigue fracture configuration was observed to SBF environment when soak was done for a long time. The fracture surface which intergranular fracture and apatite precipitated surface was observed. By the time that apatite precipitated, improvement of fracture stress was shown in a SN curve. Therefore, it was shown that corrosion fatigue strength had higher on SBF environment than deionized water environment
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The proceedings of the JSME annual meeting, 2005 451-452, 2005The study made an artificial bone of calcium phosphate bone cement and the new composites materials that content collagen and apatite. In addition, a microstructure change and crystal structure change to simulated body fluid environment were evaluated. Evaluated a compressive strength examination of the composites materials that did soak in simulated body fluid environment. In the case of the composites materials which collagen and apatite were content many in, the calcium phosphate bone paste changed in apatite easily. However, compressive strength is extremely low collagen of organic matter influences this thing. Therefore, increase quantity of collagen and apatite when considered that it changes to a bone. In other words it became clear with quantity of addition of collagen and apatite that control of a mechanical properties was possible.
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ADVANCED MATERIALS DEVELOPMENT & PERFORMANCE CONFERENCE, 54 323-324, 2005
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Journal of the Society of Materials Science, Japan, 53(4) 417-423, Apr, 2004
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The proceedings of the JSME annual meeting, 2004 313-314, 2004Pure titanium and titanium alloy are generally used as orthopaedic implants like total hip arthroplasty because of its high strength and high biocompatibility. Stability of bone-implant interfacial bonding is a critical factor for successful total hip arthroplasty. Because of the problems of loosening and dissolution of harmful ion with cemented techniques, alternative cement-less fixation of the total hip arthroplasty has been developed. Plasma spray coating of bone-like apatite is an example to add strong bonding capability with bone to metallic materials. However, this physical coating treatment shows weak base-coating bonding strength and difficult to apply on irregular surface. Chemical treatments do not have such drawbacks. The alkali-heat treatment method, developed by Kokubo et al, is a kind of chemical treatment to enhance the bone-bonding strength of pure titanium. This technique involves soaking the implant in an alkali solution and subsequent heating, resulting in a strong bone-bonding ability and a high bone affinity. This study transplants alkali heat treated titanium alloy on the rabbit femoral bone and examined in vivo interfacial bonding strength.
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Proceedings of the 1992 Annual Meeting of JSME/MMD, 2004 145-146, 2004
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The proceedings of the JSME annual meeting, 2004 125-126, 2004Compact tension specimen of hydroxyapatite ceramics (HAp) was prepared and cyclic fatigue test was performed in air, deionized water and simulated body fluid (SBF) to investigate the fatigue property of HAp. The environment where fatigue limit stress (N_f=10^7) was the lowest was deionized water environment. Subsequently was SBF environment, air environment. Fatigue fracture was observed with scanning electron microscope (SEM) to clarify this mechanism. As a result, as for the fatigue fracture configuration, fracture in transgranular was observed with high stress condition. On the other hand, intergranular fracture was observed with low stress condition. That is to say, it was stress dependence type with a short life time of case, and it was environment dependence type with a long life time of case. In addition, two fatigue fracture configuration was observed to SBF environment when soak was done for a long time. The fracture surface which intergranular fracture and apatite precipitated surface was observed. By the time that apatite precipitated, improvement of fracture stress was shown in a S-N curve. Therefore, it was shown that fatigue limit stress had higher on SBF environment than deionized water environment.
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Zairyo/Journal of the Society of Materials Science, Japan, 53(1) 101-107, 2004Metals are by far the oldest materials used in surgical procedures. Titanium alloys are hoped to be used much more for applications as implant materials in the orthopedic and dental medical fields because of their mechanical properties, such as biocompatibility, corrosion resistance and specific strength compared with other metallic implant materials. The performance of any biomedical material is controlled by two characteristics, biofunctionality and biocompatibility. Biofunctionality defines the ability of the device to perform the required function, whereas biocompatibility determines the compatibility of the material with the body. This biocompatibility is improved by coating the surface in contact with living tissues with calcium phosphates, specially hydroxyapatite. Some of the new implants utilize titanium alloys substructure coated with a thin layer of calcium phosphates ceramics, hydroxyapatite, or the plasma spray technique. Hydroxyapatite coating are designed to produce a bioactive surface promoting bone growth and inducing a direct bond between the implant and the hard tissues. The titanium metal also forms the bone like apatite layer on its surface in simulated body fluid, when it has been previously treated with NaOH aqueous solution to form a sodium titanium hydro gel layer on its surface. In the present study, surface structural changes of Ti-6Al-4V alloys with the alkali treatments and mechanical property in simulated body fluid were investigated. Thus it is expected that alkali treated titanium alloys could also form the bone like apatite layer on its surface in the living body and bond to living bone through the apatite layer. Studies have demonstrated that the bone bonding ability of titanium alloys could be evaluated by testing the titanium alloys in a simulated body fluid. In test results of with apatite coating specimens extremely higher fracture strength, compared with monolithic Ti-6Al-4V alloys whose fracture strength was 60MPa m1/2. For apatite coating Ti-6Al-4V alloys the general tendencies in the fracture strength depending upon apatite coating were understood as follows. With apatite coating Ti-6Al-4V alloys it is recognized that speculated that this tight bond might be attributed to a graded interface structure between the apatite layer and the substrates.
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7th world biomaterials congress 2004 : transactions : held May 17-21, 2004 : Sydney, Australia. : May 2004, Sydney, Australia, 809, 2004
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7th world biomaterials congress 2004 : transactions : held May 17-21, 2004 : Sydney, Australia. : May 2004, Sydney, Australia, 1762, 2004
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Advances in experimental mechanics : proceedings of the 12th International Conference on Experimental Mechanics, 50-51, 2004
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Orthopaedic ceramic implants : proceedings of Japanese Society of Orthopaedic Ceramic Implants, 23/24(24) 85-94, 2004
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BIOMATERIALS, 24(8) 1447-1457, Apr, 2003To evaluate the biological reactions to metal ions potentially released from prosthetic implants, we examined the ability of metal ions to produce bone-resorbing cytokines and the underlying mechanism using synoviocytes and bone marrow (BM) macrophages. The cells were incubated with NiCl(2), CoCl(2), CrCl(3) or Fe(2)(SO(4))(3) at optimal concentrations, which are detectable in joint fluid following total joint arthroplasty. The production of interleukin-1beta, interleukin-6 and tumor necrosis factor-alpha were enhanced by all metal ions tested as determined by enzyme-linked immunosorbent assay. From the results of electrophoresis mobility shift assay, all metal ions enhanced the DNA-binding activity of nuclear factor kappaB (NF-kappaB), and p50-p65 heterodimers and p50 homodimers were the major subunits. These effects of the metal ions were considerably blocked by pyrrolidine dithiocarbamate (PDTC) known as a radical scavenger. An electron spin resonance study clearly demonstrated the ability of metal ions to generate activated oxygen species (AOS), especially hydroxyl radicals (. OH), which accounts for PDTC-blockade of metal ion-induced NF-kappaB activation and subsequent cytokine production. Taken together, our data raised the possibility that small amounts of metal ions released from prosthetic implants activate synoviocytes and BM macrophages through the AOS-mediated process (i.e. the redox pathway), and contribute to the initiation of osteolysis at the bone-implant interface. (C) 2002 Elsevier Science Ltd. All rights reserved.
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Proceedings of the 1992 Annual Meeting of JSME/MMD, 2003 699-700, 2003
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Proceedings of the 1992 Annual Meeting of JSME/MMD, 2003 191-192, 2003
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The proceedings of the JSME annual meeting, 2003 307-308, 2003Apatite ceramics were bonds to living bone through an apatite layer that is formed on its surface in the body. It has been confirmed by SEM observation and thin film X-ray diffraction that the apatite layer can be reproduced on the surface of the hydroxyapatite ceramics even in an a cellular simulated body fluid with ion concentrations nearly equal to those of human blood plasma. In this study, we examined a static fatigue characteristic of hydroxyapatite ceramics. Examination environment is as follows, in simulated body fluid environment and laboratory environment. As a result, in SBF environment was inferior to the laboratory environment in the static fatigue characteristic. That it was trans-granular fracture was observed than static fatigue fracture side observation results in SBF environment of the specimen. It was inter-granular fracture in laboratory environment. A difference of such a fracture configuration has an influence on a static fatigue characteristic.
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9th Int. Conf. on the Mechanical Behavior of Materials, Y5, 2003
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Orthopaedic ceramic implants, 22(11) 9-17, 2003
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Proceedings of the 1992 Annual Meeting of JSME/MMD, 2002 753-754, 2002
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Evaluation of Crack Propagation Properties of Bio-Reconcilable Ti-6Al-4V Alloys by Surface TreatmentThe proceedings of the JSME annual meeting, 2002 389-390, 2002Metallic materials are widely used for orthopedic implants like artificial hip joints that bear high loads throughout its use. However, they are not capable of bonding directly to living bone. This problem will be solved if the metallic material forms hydroxyapatite (HAp) on its surface enabling living bone to bond to the metal. In this study we tried to evaluate fatigue crack propagation properties of bone-induced Ti-6Al-4V alloys in simulated body fluid (SBF), which simulates the human blood plasma in terms of ion concentrations. Bone-inducing function was added on Ti-6Al-4V alloys by coating HAp through surface treatment The fatigue crack propagation test of bone-induced Ti-6Al-4V alloys was performed under a SBF environment at 37℃. The result of the fatigue test is analyzed in terms of the fatigue crack extension rate (da/dN) vs. the stress intensity factor plots (⊿k). At stable crack propagation filed in the da/dN- ⊿k curve, the crack propagation rates of the HAp coated Ti-6Al-4V alloys and alkali-heat treatment Ti-6Al-4V alloys specimens were higher than the Ti-6Al-4V alloys without the coating. This difference is possibly caused by the stress corrosion cracking (SCC). The SEM observations of fatigue fracture surface during stable crack extension showed the evidence of SCC that occurs during fatigue crack extension in SBF environment that is observe in the coated Ti-6Al-4V and Alkali-Heat Treatment Ti-6Al-4V alloys specimens.
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日本脊椎脊髄病学会, 13(1) 212-217, Jan, 2002 Peer-reviewed
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ECF14: fracture mechanics beyond 2000: proceedings of the 14th Biennial Conference on Fracture - ECF14, held in Cracow, Poland, 8-13 September,2002, under auspices of the European Structural Integrity Society and American Society for Testing and Materials, 1(A(1)) 683, 2002
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Biological and Medical Engineering, 12 175, 2002
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Tissue Engineering, 7(5) 635-674, Oct, 2001
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Journal of Japanese Society for Biomaterials, 19(4) 3-13, Aug, 2001
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The Society of Material Science JAPAN, 50(5) 558, May, 2001
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Proceedings of the 1992 Annual Meeting of JSME/MMD, 2001 275-276, 2001
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Proceedings of the 1992 Annual Meeting of JSME/MMD, 2001 529-530, 2001The number of aged person is increasing having a disease for bone, tooth and innards. So the necessity of these substitute materials must be increasing. Alumina ceramics are used for substitute materials as bonehead of a thighbone joint, because of its high strength and bio-inert properties. For many biomaterials a fracture occurs due to both corrosion and fatigue. In this study, effects of similar body fluid (SBF) environment on mechanical properties and microstructure of Al_2O_3 were investigated. Microstructural changes of Al_2O_3 ceramics due to SBF corrosion degradation were also examined by scanning electron microscope after long time immersion into SBF at 37℃. Degradation of bending strength and fracture toughness (K_C) were evaluated.
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Nihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A, 67(657) 844-851, 2001High-temperature and high-pressure water corrosion behaviors of Y 2O3 doped Zirconia (ZrCh2) were investigated in term of with the microstructural changes, residual strength characteristics and tetragonal to monoclinic phase transformation. Sintered ZrO2 ceramics bodies with 2, 3, 4, 6 and 8mol% Y2O3 doped ZrO2 were made using a pressure less sintering method at 1 450°C, respectively. These ZtO2 ceramics were corroded in high-temperature and high-pressure water condition such as 150°C-300°C. Corrosion damage of the decrease Y2O3 dope ZrO2 ceramics occurred preferentially on ZrO2 particle after long-term immersion in high-temperature and high-pressure water environment. The tetragonal to monoclinic phase transformation occurred in decrease Y2O3 doped tetragonal ZrO2 ceramics due to high-temperature and high-pressure water corrosion. For improvement of the corrosion characteristics (thermal stability) of the ZrO2 ceramics, are important increasing the Y2O3 doped within a range in which no remarkable residual strength degradation is recognized. CeO2 doped ZrO 2 ceramics were useful to improvement the thermal stability of Y 2O3 doped ZrO2 without loss of the fracture strength. CeO2 doped ZrO2 ceramics also have superior residual strength characteristics compared to Y-ZrO2 ceramics. In addition design concepts used to obtain water- corrosion-resistant high strength and high toughness ZrO2 ceramics were proposed.
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Materials science for the 21st century, B 265-268, 2001
Misc.
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2016(69) 115-116, Mar 15, 2016
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2015 "GS0607-427-1"-"GS0607-427-3", Nov 21, 2015Barrel, nozzle and screw are plasticization parts of injection molding machines that works under high processing temperature. These parts are also exposed to corrosive gas and acid environment came from molten plastics. These combined factors cause considerable corrosion damage on plasticization parts. Furthermore, frictions with glass-filled polymers in molten plastic give rise to wear damages simultaneously on plasticization parts. In this study, the electrochemical test has been conducted on SKD61 specimens in the solute H_2SO_4 dissolving nylon66-25wt.% fiberglass. It was found that oxide film formation was promoted due to the oxidation reaction between SKD61 surface and the solution while the regenerative ability of the oxide film of SKD61 was deteriorated. The corrosion wear test was also conducted by using Alumina ceramics ball on SKD61 disk specimens. Destruction of the oxide film of SKD61 due to friction was confirmed. The regenerative ability of oxide film was also verified in the test.
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2015 "OS1313-426-1"-"OS1313-426-3", Nov 21, 2015Shot peening (SP) is one of the surface modification technologies to enhance fatigue strength. In this study, the mechanism of enhancement of bending fatigue property of shot peened pure titanium (JIS 2) was investigated. Surface roughness, vickers hardness of surface and subsurface, and bending fatigue strength was measured. Surface roughness and hardness of surface and subsurface were increased by SP. The bending fatigue strength was increased highly by SP because increasing of hardness effected more greatly than increasing of surface roughness. The maximum of amount of increase 2.7 times in 10^7 cycles. It was found that the bending fatigue strength was increased by increasing of hardness of surface and subsurface by SP. Therefore, it is obvious that fatigue strength of pure titanium is increased highly by SP.
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2015 "OS1314-447-1"-"OS1314-447-3", Nov 21, 2015Torsion fatigue tests were conducted for circumferentially notched bars specimens of Ti-6Al-4V alloy to evaluate fatigue strength. The notch sensitivity was studied by using blunt (stress concentration factor Kt=2.0) and sharp (Kt=4.0) notched specimens. The number of cycles to failure was obtained and the crack initiation life was estimated from the applied torque to the specimens. The number of cycles to failure and fatigue strength decreased with increasing the value of stress concentration factor. When compared at the same fatigue life, the crack initiation life of Kt=4.0 specimen was much shorter than that of Kt=2.0. The crack propagation behaviors were analyzed by observing fractured surface. When stress amplitude is low, the tensile crack propagated toward a 45° direction of the longitudinal axis of the specimen, while under high stress amplitude, the shear crack propagated in the circumferential direction both in blunt and sharp notched specimens forming flat fracture surface. The fracture surface showed factory-roof pattern under middle stress amplitude. The angle of a fracture plane of the blunt notch under low stress amplitude was 45° to the axial direction. The formation of factory-roof may increase contact areas in the fractured surface, thus increase crack propagation life.
Books and Other Publications
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Japan Institute of Metals and Materials, Oct, 2014 (ISBN: 9784889030761)
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Jul, 2013 (ISBN: 9784890447725)
Presentations
33Professional Memberships
16Research Projects
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教育研究資金, 公益社団法人軽金属奨学会, Apr, 2022 - Mar, 2024
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Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, Apr, 2019 - Mar, 2022
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Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Japan Society for the Promotion of Science, Apr, 2016 - Mar, 2019
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Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Japan Society for the Promotion of Science, Apr, 2013 - Mar, 2016
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Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B), Japan Society for the Promotion of Science, 2010 - 2012
Industrial Property Rights
7Social Activities
5Other
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Sep, 2018 - Sep, 2018これから疲労設計に携わろうとする若手技術者，新たに耐疲労設計を必要とする技術者や疲労研究を従事する大学院生など，いわゆる疲労に関する初心者を対象に，疲労の基礎的知識から具体的な設計の初歩を講述する講習会
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Aug, 2017 - Aug, 2017これから疲労設計に携わろうとする若手技術者，新たに耐疲労設計を必要とする技術者や疲労研究を従事する大学院生など，いわゆる疲労に関する初心者を対象に，疲労の基礎的知識から具体的な設計の初歩を講述する講習会
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Sep, 2016 - Sep, 2016これから疲労設計に携わろうとする若手技術者，新たに耐疲労設計を必要とする技術者や疲労研究を従事する大学院生など，いわゆる疲労に関する初心者を対象に，疲労の基礎的知識から具体的な設計の初歩を講述する講習会
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Aug, 2015 - Sep, 2015これから疲労設計に携わろうとする若手技術者，新たに耐疲労設計を必要とする技術者や疲労研究を従事する大学院生など，いわゆる疲労に関する初心者を対象に，疲労の基礎的知識から具体的な設計の初歩を講述する講習会