Yoshio Harada
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View article: OS1519 Effect of interlayer thickness on fatigue behavior of A5052 aluminum alloy with DLC/anodic oxide hybrid coating
OS1519 Effect of interlayer thickness on fatigue behavior of A5052 aluminum alloy with DLC/anodic oxide hybrid coating Open
Anodic oxide layer was formed on A5052 aluminum alloy, and subsequently DLC was deposited on it to fabricate DLC/anodic-oxide hybrid coating. Rotating bending fatigue testes have been performed using the hybrid-coated specimens with differ…
View article: Effect of Film Elastic Modulus on Fatigue Behaviour of DLC-Coated Wrought Magnesium Alloy AZ61
Effect of Film Elastic Modulus on Fatigue Behaviour of DLC-Coated Wrought Magnesium Alloy AZ61 Open
Plane bending fatigue tests were conducted using DLC-coated magnesium alloy AZ61 with two different film elastic moduli in order to investigate the effect of film elastic modulus on fatigue behaviour. Fatigue strength was improved by DLC f…
View article: G030094 Fatigue Behavior of A5052 Aluminum Alloy with DLC/Thermally Sprayed WC-12Co Hybrid Coatings
G030094 Fatigue Behavior of A5052 Aluminum Alloy with DLC/Thermally Sprayed WC-12Co Hybrid Coatings Open
Cantilever type rotating bending fatigue tests were performed using A5052 aluminum alloy with hybrid coating of tungsten carbide including 12% cobalt (WC-12Co) interlayer and diamond-like carbon (DLC) film in order to investigate the effec…
View article: Effect of DLC Film on Fatigue Behavior in Alloy Steels with Different Hardness and Inclusion Size
Effect of DLC Film on Fatigue Behavior in Alloy Steels with Different Hardness and Inclusion Size Open
Rotary bending fatigue tests have been conducted using DLC-coated alloy steels, SKD11, SKD61 and SNCM439, with different hardness and carbide or inclusion size in order to investigate the effect of DLC film on the fatigue behavior. DLC fil…
View article: In Situ Observation of Creep and Fatigue Failure Behavior for Plasma-Sprayed Thermal Barrier Coating Systems
In Situ Observation of Creep and Fatigue Failure Behavior for Plasma-Sprayed Thermal Barrier Coating Systems Open
In order to investigate crack initiation sites and the crack propagation behavior in connection with the microstructure of thermal barrier coating (TBC) systems under creep and fatigue loadings, the failure behavior was observed in situ fo…
View article: Young's Modulus of Thermal Barrier Coating and Oxidation Resistant Coating Bonded to Stainless Substrate by Four-Point Bending
Young's Modulus of Thermal Barrier Coating and Oxidation Resistant Coating Bonded to Stainless Substrate by Four-Point Bending Open
Young's modulus of thermal barrier coating (TBC) is one of the most essential mechanical properties on the designing of high performance TBC system. This paper describes one of the round-robin test results of New Energy and Industrial Tech…
View article: In Situ Observation of Creep and Fatigue Failure Behavior for Plasma-Sprayed Thermal Barrier Coating Systems(<Special Issue>Thermal Barrier Coating Systems for Gas Turbines)
In Situ Observation of Creep and Fatigue Failure Behavior for Plasma-Sprayed Thermal Barrier Coating Systems(Thermal Barrier Coating Systems for Gas Turbines) Open
In order to investigate crack initiation sites and the crack propagation behavior in connection with the microstructure of thermal barrier coating (TBC) systems under creep and fatigue loadings, the failure behavior was observed in situ fo…
View article: Fatigue Behaviour of Stainless Steel with HVOF and Atmospheric Plasma Sprayed Alumina Ceramics
Fatigue Behaviour of Stainless Steel with HVOF and Atmospheric Plasma Sprayed Alumina Ceramics Open
Rotating bending fatigue tests have been conducted in laboratory air using type 403 stainless steel with Al_2O_3 coating thermally sprayed by high velocity oxygen fuel (HVOF) process. Two different coating thicknesses of 150μm and 300μm we…
View article: Effect of Bond-Coat Processing on Creep and Fatigue Strength Properties of Plasma Sprayed Thermal Barrier Coating Systems
Effect of Bond-Coat Processing on Creep and Fatigue Strength Properties of Plasma Sprayed Thermal Barrier Coating Systems Open
In order to clarify different manners of failure behavior for plasma sprayed thermal barrier coating (TBC) systems under the complicated modes of thermal-mechanical-chemical loadings, the stress rupture properties was evaluated in air and …
View article: OS0816 Standardization for evaluating mechanical properties of heat resistant coatings : Residual stress measurement based on bending displacement method
OS0816 Standardization for evaluating mechanical properties of heat resistant coatings : Residual stress measurement based on bending displacement method Open
遮熱コーティングの残留応力測定手法の標準化を目的として,コーティング施工後の部材の変形量から固有ひずみ法に基づく残留応力分布の推定方法を検討している.大気プラズマ溶射法によるコーティング施工時に試験片の片端を固定し,自由端側の変位量を逐次計測する方法を用いて,施工時の試験片の変形挙動を調べ,冷却後に残存する変形量からコーティング部材の残留応力分布を推定した.その結果,遮熱コーティング部材の残留応力測定方法として,本手法の有効性を確認することができた.
View article: OS0813 Microstructural Features of Mechanical Failure Behavior for Electron Beam Physical Vapor Deposited Thermal Barrier Coating System
OS0813 Microstructural Features of Mechanical Failure Behavior for Electron Beam Physical Vapor Deposited Thermal Barrier Coating System Open
高温酸化により組成・組織を変化させたEB-PVD法TBCシステムを対象に,機械的損傷挙動のその場観察を室温と900℃で実施し,損傷劣化挙動に及ぼす組織学的因子の影響について,未酸化材およびプラズマ溶射TBCシステムの場合と対比しながら検討した.その結果,EB-PVD法トップコート(TC)層は,TC柱状晶間ギャップの開閉口挙動に起因した優れたひずみ収容機能を発揮する反面,高温酸化によりTGO層の厚膜化やTC層のち密化が促進され,TCのはく離抵抗性が著しく低下することが明らかと…
View article: Effect of Coating Process Condition on High-Temperature Oxidation and Mechanical Failure Behavior for Plasma Sprayed Thermal Barrier Coating Systems
Effect of Coating Process Condition on High-Temperature Oxidation and Mechanical Failure Behavior for Plasma Sprayed Thermal Barrier Coating Systems Open
In order to clarify the thermal and/or mechanical failure behavior of the plasma sprayed thermal barrier coating (TBC) system in connection with their coating characteristics depending on the coating process condition, two kinds of the fai…
View article: The Important Role of Engineering in Corrosion Control of Heavy Oil Fired Boilers
The Important Role of Engineering in Corrosion Control of Heavy Oil Fired Boilers Open
重油燃焼ボイラで発生する高温腐食は，典型的なバナジウム腐食として知られ，腐食された管を調査すると，酸化層の下に金属硫化層と浸炭現象が存在している．これらの現象は，合成灰による実験室腐食試験では明らかにすることができない．高温腐食を防止するためMgO，Mg(OH)2などの添加剤が燃料中へ注入されている．添加剤とバナジウム化合物との化学反応によって形成される高融点で，腐食性のない反応生成物によって，管の腐食速度は減少する．しかし，これらの添加剤は，白色のMg添加剤が燃焼室管に付…
View article: OS0817 Activities toward Standardization for evaluating mechanical properties of thermal barrier coatings : Measurement of residual stress by stress-relief method
OS0817 Activities toward Standardization for evaluating mechanical properties of thermal barrier coatings : Measurement of residual stress by stress-relief method Open
本研究では,大気プラズマ溶射法によって製作した遮熱コーティング試験片の残留応力について,組合せはりの理論を適用し,応力解放法により測定した.一連の測定結果を紹介するとともに,この手法により残留応力を測定する際の今後の課題についても検討した.
View article: OS0818 Standardization for evaluating mechanical properties of heat resistant coatings : Flexural strength measurement
OS0818 Standardization for evaluating mechanical properties of heat resistant coatings : Flexural strength measurement Open
NEDO委託「耐熱コーティング膜の特性評価試験方法に関する標準化調査事業」の一環として,遮熱コーティングの曲げ強さ試験方法の標準化を目指し,大気プラズマ溶射法によって作製したボンドコート(BC)試験片および遮熱コーティング(TBC)試験片を対象に,4点曲げ試験法によってコーティングに引張もしくは圧縮負荷を加えた際の曲げ特性を調べた.その結果,BC試験片では,引張負荷条件下でコーティングに損傷が発生するひずみ量は基材に対するコーティングの膜厚比に強く依存して変化する一方,TB…
View article: OS0814 Standardization for evaluating mechanical properties of heat resistant coatings ] Elastic modulus measurement based on bending of composite beam
OS0814 Standardization for evaluating mechanical properties of heat resistant coatings ] Elastic modulus measurement based on bending of composite beam Open
遮熱コーティングの弾性係数評価法の標準化を目的とし,4点曲げ試験を実施した.積層梁の曲げ理論を用い,常温で高精度に測定できる手法としてひずみゲージ法,高温への適用も可能なたわみ法の両手法で評価した.ひずみゲージ法では皮膜ひずみ法が最も高精度であることが分かった.たわみ法では曲げスパンが長い場合に良好に評価可能であり,適切なスパンを明らかにした.ひずみゲージ法・たわみ法とも皮膜の厚さが基材の厚さと比べて大きい場合良好に評価可能であり,適切な厚さ比を明らかにした.
View article: Sulfide Corrosion Resistance and Adhesive Strength of a High Cr-Fe Alloy Plasma Spray Coating Applied to the Inner Surface of Cylindrical Aluminum Containers of NAS Batteries to Store Electrical Power for Extended Period of Time
Sulfide Corrosion Resistance and Adhesive Strength of a High Cr-Fe Alloy Plasma Spray Coating Applied to the Inner Surface of Cylindrical Aluminum Containers of NAS Batteries to Store Electrical Power for Extended Period of Time Open
The characteristics and adhesive strength of a high Cr-Fe alloy plasma spray coating applied to the inner surface of cylindrical aluminum containers of 17 NAS battery cell used to leveling electrical power for 0.2 to 10 years were studied.…
View article: Surface Strain Measurement of Thermally Sprayed Ceramics Coatings under Static and Cyclic Loadings and Its Application to Detection of Delamination
Surface Strain Measurement of Thermally Sprayed Ceramics Coatings under Static and Cyclic Loadings and Its Application to Detection of Delamination Open
Thermally sprayed ceramic coatings are commonly used as thermal barriers at high temperature. However, delamination of the coating from substrate (base metal) under various operation conditions, including high temperature and mechanical lo…
View article: Effects of Preheating Temperature of NAS Battery Al Cylinders on the Flattening Behaviors of High Cr-Fe Alloy Plasma Spray Particles and the Adhesion Strength of Internally Sprayed Coatings
Effects of Preheating Temperature of NAS Battery Al Cylinders on the Flattening Behaviors of High Cr-Fe Alloy Plasma Spray Particles and the Adhesion Strength of Internally Sprayed Coatings Open
In order to improve the adhesion of 75 mass% Cr-Fe alloy plasma spray coatings, which provide sulfide corrosion resistance for the inner surface of NAS battery high-temperature type Al cylinders, the Al substrate temperature and the flatte…
View article: Measurement of Permeable Pores in High Cr-Fe Alloy Plasma Sprayed Coating Formed on the Inner Surface of Aluminum Container for NAS Batteries Cell
Measurement of Permeable Pores in High Cr-Fe Alloy Plasma Sprayed Coating Formed on the Inner Surface of Aluminum Container for NAS Batteries Cell Open
Test methods were studied for determining whether permeable pores exist in high Cr-Fe alloy plasma spray coatings applied to the inner surface NAS battery Al containers. Al containers were first filled with a NaOH solution. If permeable po…
View article: OS6-1-2 Effect of coating process condition on high-temperature oxidation and mechanical failure behavior for plasma sprayed thermal barrier coating systems
OS6-1-2 Effect of coating process condition on high-temperature oxidation and mechanical failure behavior for plasma sprayed thermal barrier coating systems Open
In order to clarify the thermal and / or mechanical failure behavior of the plasma sprayed thermal barrier coating (TBC) system in connection with their coating characteristics such as the coating microstructures and interfacial natures de…
View article: Effects of Preheating Temperature of NAS Battery Al Cylinders on the Flattening Behaviors of High Cr-Fe Alloy Plasma Spray Particles and the Adhesion of Internally Sprayed Coatings
Effects of Preheating Temperature of NAS Battery Al Cylinders on the Flattening Behaviors of High Cr-Fe Alloy Plasma Spray Particles and the Adhesion of Internally Sprayed Coatings Open
In order to improve the adhesion of 75 mass% Cr-Fe alloy plasma spray coatings, which provide sulfide corrosion resistance for the inner surface of NAS battery high-temperature type Al cylinders, the Al substrate temperature and the flatte…
View article: Influence of Post-Sprayed Heat Treatment Conditions on High-Temperature Oxidation Property for Plasma Sprayed Thermal Barrier Coating Systems
Influence of Post-Sprayed Heat Treatment Conditions on High-Temperature Oxidation Property for Plasma Sprayed Thermal Barrier Coating Systems Open
In order to improve the high-temperature durability of the plasma sprayed thermal barrier coating (TBC) systems, high-temperature oxidation test was conducted under the isothermal condition at 1100°C for 100 h for several kinds of TBC syst…