The Experts below are selected from a list of 4479 Experts worldwide ranked by ideXlab platform
H. Wang - One of the best experts on this subject based on the ideXlab platform.
-
Residual Stress Relaxation in the film/substrate system due to creep deformation
Journal of Applied Physics, 2007Co-Authors: Xiujuan Zhang, H. WangAbstract:An analytical model is developed to estimate the effect of creep deformation on the Stress Relaxation and distribution in the film/substrate bilayer structure during prolonged exposure to high temperature. In the model, either the film or the substrate subjecting to high-temperature creep is considered. Closed-form solutions for the Residual Stresses in the film and the substrate are derived. A relationship between the Stress Relaxation rate in the film/substrate system and the Relaxation time is obtained. Case studies show that the ratios of the biaxial modulus and the thickness of the film to those of the substrate, the creep parameters, and the exposure temperature have significant influence on the Residual Stress Relaxation rate.
-
Residual Stress Relaxation in the film substrate system due to creep deformation
Journal of Applied Physics, 2007Co-Authors: Xiujuan Zhang, H. WangAbstract:An analytical model is developed to estimate the effect of creep deformation on the Stress Relaxation and distribution in the film/substrate bilayer structure during prolonged exposure to high temperature. In the model, either the film or the substrate subjecting to high-temperature creep is considered. Closed-form solutions for the Residual Stresses in the film and the substrate are derived. A relationship between the Stress Relaxation rate in the film/substrate system and the Relaxation time is obtained. Case studies show that the ratios of the biaxial modulus and the thickness of the film to those of the substrate, the creep parameters, and the exposure temperature have significant influence on the Residual Stress Relaxation rate.
Omar Suliman Zaroog - One of the best experts on this subject based on the ideXlab platform.
-
Modeling of Residual Stress Relaxation of fatigue in 2024-T351 aluminium alloy
International Journal of Fatigue, 2011Co-Authors: Omar Suliman Zaroog, Barkawi Sahari, Aidy Ali, Rizal ZahariAbstract:The initial induced compressive Residual Stresses relax during component operating life and it is important to consider the Relaxation phenomenon in the design of the component. In this study, 2024-T 351 aluminium alloy specimens were shot peened under three different shot-peening intensities. Cyclic tests for two load magnitudes were performed for 1, 2, 10, 1000 and 10,000 cycles. The initial and final Residual Stresses and the cold work after each loading cycle were measured for the three shot-peening intensities and for the two load magnitudes using X-ray diffraction. The initial and final microhardnesses after each loading cycle load were also measured for the three shot-peening intensities. The results showed that the reduction in the Residual Stress, microhardness and cold work are dependent on the applied load. An empirical model was proposed to estimate the Residual Stress Relaxation. The presented model incorporates parameters including the degree of cold work, initial induced Residual Stress and the number of applied loading cycles.
-
Micro-Hardness and Residual Stress Relaxation of 2024 T351 Aluminum Alloy
Key Engineering Materials, 2011Co-Authors: Omar Suliman Zaroog, Barkawi Sahari, Aidy Ali, Rizal ZahariAbstract:The Residual Stress Relaxation can be divided into two stages: The first cycle Relaxation and the following cycles. In both stages, Residual Stress relaxed considerably from the initial state. The aim of this study is to investigate the Residual Stress Relaxation and microhardness reduction after first and second cyclic load. A 2024 T351 aluminum alloy specimens were shot peened into three shot peening intensities. The fatigue test for first and second cyclic loads of two loads 15.5 kN and 30 kN was performed. The initial Residual Stress and Residual Stress after the first and second cycle Stress was measured for the three shot peening intensities using X-ray diffraction. Microhardness test was performed for each specimen. The results showed that the Residual Stress Relaxation for first cycle was reached more than 40% of the initial Residual Stress and it depends on the load amplitude, and microhardness decreased for the first cycle reached 22% and also it depended on load amplitude.
-
Prediction of Residual Stress Relaxation of Shot Peened 2024-T351 Aluminum Alloy: Part 1
Key Engineering Materials, 2011Co-Authors: Omar Suliman Zaroog, Aidy Ali, Barkawi SahariAbstract:It is important to account for Residual Stress Relaxation phenomenon in the design of the component. Specimens of 2024-T351 aluminium alloy were used in this study. The specimens were shot peened under three different shot peening intensities. Cyclic tests for two load magnitudes were performed for 1, 2, 10, 1000 and 10000 cycles. Residual Stresses, microhardness and the cold work percentage were measured at initial state and after each loading cycle for the three shot peening intensities and for the two loads. The study revealed that most of the drop in the Residual Stress, microhardness and cold work happened in the first cycle are dependent on the applied load.
-
Prediction of Residual Stress Relaxation of shot peened 2024-T351 aluminum alloy: Part 2
Key Engineering Materials, 2011Co-Authors: Omar Suliman Zaroog, Aidy Ali, Barkawi SahariAbstract:The initial compressive Residual Stresses induced or inherent in a component will not remain stable during the life of the component, it relax and redistributed. In design of the component, it is important to consider the Relaxation of Residual Stress phenomenon. In this study, equations to predict Residual Stress Relaxation of 2024 T351 aluminium alloy specimens were proposed. The equations developed from the experimental data of 2024 T351 aluminium alloy specimens that were shot peened under three different shot peening intensities and undergoing cyclic tests for two load magnitudes for 1, 2, 10, 1000 and 10000 cycles. The Residual Stress, cold work and microhardness results were recorded after each cyclic load as well as the initial state. The presented model incorporates parameters including the degree of cold work, initial induced Residual Stress and the number of applied loading cycles.
-
Residual Stress Relaxation of shot-peened 2024-T351 aluminium alloy
2011Co-Authors: Omar Suliman ZaroogAbstract:Near surface tensile Residual Stresses tend to accelerate the initiation and growth phases of the fatigue process while compressive Residual Stresses close to a surface may prolong fatigue life and consider as beneficial Residual Stresses. Shot peening process used to induce beneficial compressive Residual Stress in materials. However, the Residual Stresses may relax due to thermal, static mechanical load and cyclic load. Even with partial Relaxation, there found a beneficial effect of compressive Residual Stress on fatigue life. The problem is how much is the Relaxation? To answer this question a 2024 T351 aluminium alloy specimens were shot peened into three shot peening intensities 0.0054 A, 0.0067 A and 0.009 A. The cyclic test for the two loads magnitude, 15.5 kN and 30 kN, was performed for the 1, 2, 10, 1000 and 10000 cycles. The initial Residual Stress and Residual Stress as well as cold work after each cyclic load were measured for the three shot peening intensities and for the two magnitudes of loads using X-ray diffraction method. Initial and after microhardness of each cyclic load were measured for the three shot peening intensities. The results showed that the most Relaxation of the initial Residual Stress took place in the first cycle; the initial Residual Stress was relaxed by 46% after first cycle in the load 30 kN and shot peening intensity of 0.0054 A. Relaxation of Residual Stresses occurred within first loading cycles were increasing with increasing loading Stress amplitude and due to quasi-static Relaxation effects. The Residual Stress after the first cycle found to relax depends on the load amplitude. The maximum Relaxation found is 54% of the initial Residual Stress in the shot peen intensity of 0.0054 A after 10000 cycles for the load of 30 kN. The changed in the Relaxation percentages of all specimens from 10 cyclic load to 10000 cyclic load is in the range of 5-8% of the initial Residual Stress. Microhardnesses were found to decrease depending on the load amplitude. A load of 30 kN made microhardness in the specimens decrease more than the 15.5 kN load. The microhardness was reduced by 39%, given a shot peen intensity of 0.009 A after 10000 cycles under a load of 30 kN. From observations and results, empirical equations to estimate the Residual Stress Relaxation were proposed. The equations incorporated the number of cycles and cold work to predict the amount of Residual Stress Relaxation. Finally, the results of the estimation are in a good agreement with experimental data.
Chuanhai Jiang - One of the best experts on this subject based on the ideXlab platform.
-
Residual Stress Relaxation and micro structural development of the surface layer of 18crnimo7 6 steel after shot peening during isothermal annealing
Materials & Design, 2014Co-Authors: Peng Fu, Chuanhai JiangAbstract:Abstract The variations of micro-structure, Residual Stress and micro-hardness for 18CrNiMo7-6 steel after triple shot peening (SP) in function of annealing time and temperature were studied. X-ray diffraction line profile analysis (XRDLPA) was used to identify variation of micro-structure and Residual Stress Relaxation behaviors on the top surface of 18CrNiMo7-6 steel after SP during isothermal annealing. The results show that the micro-strain, dislocation density, stored energy, compressive Residual Stress (CRS) and micro-hardness on the top surface of 18CrNiMo7-6 steel after SP decrease with the increase of annealing time. But the domain size increases with increasing annealing time at four different temperatures. Indeed, the change rates of micro-structure, Residual Stress and micro-hardness are bigger at a higher annealing temperature or for a longer annealing time.
-
Residual Stress Relaxation of Shot-Peened Deformation Surface Layer on Duplex Stainless Steel Under Applied Loading
Journal of Materials Engineering and Performance, 2013Co-Authors: Qiang Feng, Chuanhai JiangAbstract:The Relaxation of Residual Stress in shot-peened surface layer of duplex stainless steel S32205 under static and cyclic loading was investigated. The results reveal that the compressive Residual Stress is relaxed under applied tensile Stress. The Relaxation of Residual Stress in longitudinal direction is more obvious than that in transverse direction in both austenite and ferrite. When the applied Stress is beyond the yield strength of the materials, the Relaxation of the Residual Stress becomes drastic. Under cyclic loading, the Residual Stress Relaxation occurs fast in the first few cycles, it then becomes stable gradually. A model was used to quantitatively calculate the Residual Stress under cyclic loading with different applied tensile Stresses. The Relaxation behavior is determined by the applied loading, the number of cycles, dislocation density, and the Residual Stress gradient. The Relaxation behavior difference under cyclic loading between ferrite and austenite is discussed.
-
Influence of annealing on the shot-peened surface of duplex stainless steel at elevated temperatures
Nuclear Engineering and Design, 2013Co-Authors: Qiang Feng, Chuanhai Jiang, Ke ZhanAbstract:Abstract In order to investigate the Residual Stress Relaxations of shot-peened surface, isothermal annealing treatments were carried out on duplex stainless steel (DSS) S32205 after shot peening (SP) with temperature ranging from 600 to 700 °C. A new phase with a tetragonal crystal structure (σ-phase) appears apparently at the annealing temperature of 700 °C for 64 min. The rates of Residual Stress Relaxation in austenite (γ-phase) are higher than that in ferrite (α-phase) under the corresponding annealing temperature for 64 min. The Residual-Stress Relaxation process during isothermal annealing could be described by Zener–Wert–Avrami function. The activation enthalpy for Residual Stress Relaxation in γ-phase is lower than that in α-phase. At temperature of 700 °C, the microhardness increases gradually after reduction at the initial stage because the strengthening of the new σ-phase is dominating with the prolongation of annealing time, the content-increased γ-phase may also have a certain contribution.
Xiujuan Zhang - One of the best experts on this subject based on the ideXlab platform.
-
Residual Stress Relaxation in the film/substrate system due to creep deformation
Journal of Applied Physics, 2007Co-Authors: Xiujuan Zhang, H. WangAbstract:An analytical model is developed to estimate the effect of creep deformation on the Stress Relaxation and distribution in the film/substrate bilayer structure during prolonged exposure to high temperature. In the model, either the film or the substrate subjecting to high-temperature creep is considered. Closed-form solutions for the Residual Stresses in the film and the substrate are derived. A relationship between the Stress Relaxation rate in the film/substrate system and the Relaxation time is obtained. Case studies show that the ratios of the biaxial modulus and the thickness of the film to those of the substrate, the creep parameters, and the exposure temperature have significant influence on the Residual Stress Relaxation rate.
-
Residual Stress Relaxation in the film substrate system due to creep deformation
Journal of Applied Physics, 2007Co-Authors: Xiujuan Zhang, H. WangAbstract:An analytical model is developed to estimate the effect of creep deformation on the Stress Relaxation and distribution in the film/substrate bilayer structure during prolonged exposure to high temperature. In the model, either the film or the substrate subjecting to high-temperature creep is considered. Closed-form solutions for the Residual Stresses in the film and the substrate are derived. A relationship between the Stress Relaxation rate in the film/substrate system and the Relaxation time is obtained. Case studies show that the ratios of the biaxial modulus and the thickness of the film to those of the substrate, the creep parameters, and the exposure temperature have significant influence on the Residual Stress Relaxation rate.
Barkawi Sahari - One of the best experts on this subject based on the ideXlab platform.
-
Modeling of Residual Stress Relaxation of fatigue in 2024-T351 aluminium alloy
International Journal of Fatigue, 2011Co-Authors: Omar Suliman Zaroog, Barkawi Sahari, Aidy Ali, Rizal ZahariAbstract:The initial induced compressive Residual Stresses relax during component operating life and it is important to consider the Relaxation phenomenon in the design of the component. In this study, 2024-T 351 aluminium alloy specimens were shot peened under three different shot-peening intensities. Cyclic tests for two load magnitudes were performed for 1, 2, 10, 1000 and 10,000 cycles. The initial and final Residual Stresses and the cold work after each loading cycle were measured for the three shot-peening intensities and for the two load magnitudes using X-ray diffraction. The initial and final microhardnesses after each loading cycle load were also measured for the three shot-peening intensities. The results showed that the reduction in the Residual Stress, microhardness and cold work are dependent on the applied load. An empirical model was proposed to estimate the Residual Stress Relaxation. The presented model incorporates parameters including the degree of cold work, initial induced Residual Stress and the number of applied loading cycles.
-
Micro-Hardness and Residual Stress Relaxation of 2024 T351 Aluminum Alloy
Key Engineering Materials, 2011Co-Authors: Omar Suliman Zaroog, Barkawi Sahari, Aidy Ali, Rizal ZahariAbstract:The Residual Stress Relaxation can be divided into two stages: The first cycle Relaxation and the following cycles. In both stages, Residual Stress relaxed considerably from the initial state. The aim of this study is to investigate the Residual Stress Relaxation and microhardness reduction after first and second cyclic load. A 2024 T351 aluminum alloy specimens were shot peened into three shot peening intensities. The fatigue test for first and second cyclic loads of two loads 15.5 kN and 30 kN was performed. The initial Residual Stress and Residual Stress after the first and second cycle Stress was measured for the three shot peening intensities using X-ray diffraction. Microhardness test was performed for each specimen. The results showed that the Residual Stress Relaxation for first cycle was reached more than 40% of the initial Residual Stress and it depends on the load amplitude, and microhardness decreased for the first cycle reached 22% and also it depended on load amplitude.
-
Prediction of Residual Stress Relaxation of Shot Peened 2024-T351 Aluminum Alloy: Part 1
Key Engineering Materials, 2011Co-Authors: Omar Suliman Zaroog, Aidy Ali, Barkawi SahariAbstract:It is important to account for Residual Stress Relaxation phenomenon in the design of the component. Specimens of 2024-T351 aluminium alloy were used in this study. The specimens were shot peened under three different shot peening intensities. Cyclic tests for two load magnitudes were performed for 1, 2, 10, 1000 and 10000 cycles. Residual Stresses, microhardness and the cold work percentage were measured at initial state and after each loading cycle for the three shot peening intensities and for the two loads. The study revealed that most of the drop in the Residual Stress, microhardness and cold work happened in the first cycle are dependent on the applied load.
-
Prediction of Residual Stress Relaxation of shot peened 2024-T351 aluminum alloy: Part 2
Key Engineering Materials, 2011Co-Authors: Omar Suliman Zaroog, Aidy Ali, Barkawi SahariAbstract:The initial compressive Residual Stresses induced or inherent in a component will not remain stable during the life of the component, it relax and redistributed. In design of the component, it is important to consider the Relaxation of Residual Stress phenomenon. In this study, equations to predict Residual Stress Relaxation of 2024 T351 aluminium alloy specimens were proposed. The equations developed from the experimental data of 2024 T351 aluminium alloy specimens that were shot peened under three different shot peening intensities and undergoing cyclic tests for two load magnitudes for 1, 2, 10, 1000 and 10000 cycles. The Residual Stress, cold work and microhardness results were recorded after each cyclic load as well as the initial state. The presented model incorporates parameters including the degree of cold work, initial induced Residual Stress and the number of applied loading cycles.
-
Residual Stress Relaxation and surface hardness of a 2024-t351 aluminium alloy
Materials Testing-Materials and Components Technology and Application, 2010Co-Authors: Omar Suliman Zaroog, Barkawi Sahari, Aidy Ali, Rizal ZahariAbstract:Abstract For design it is generally important to consider the Residual Stress Relaxation. In the study for this contribution, 2024 T351 Aluminium alloy specimens were shot peened at three different shot peening intensities, followed by fatigue tests for two loads. Fatigue tests were divided into two stages. The Residual Stresses and micro-hardness were measured at initial and after each cyclic load for the three shot peening intensities and the two aforementioned sets of loads. The results showed that the Residual Stresses and micro-hardness of the specimens were decreased. Moreover, the Relaxation depended on the fatigue load amplitude. Residual Stress Relaxation reached 54% of the initial Residual Stress while the micro-hardness Relaxation reached 39% of the initial micro-hardness. Most of the Residual Stress Relaxation occurred during the first cycle. The Relaxation of the initial Residual Stress is severe when there is low shot peening intensity and high applied load, and the reduction of the micro-ha...