The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform
Jianzhong Zhou - One of the best experts on this subject based on the ideXlab platform.
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effects of laser peening on residual stresses and Fatigue crack growth properties of ti 6al 4v titanium alloy
Optics and Lasers in Engineering, 2014Co-Authors: Jianzhong Zhou, Jie Sheng, Shu Huang, L D Zuo, Xiankai Meng, Q Tian, Y H Han, Weili ZhuAbstract:Abstract The effects of laser peening (LP) with different laser peening coverage rates on residual stresses and Fatigue crack growth (FCG) properties of Ti–6Al–4V titanium alloy were investigated. Residual stresses after LP and micro-structure with different Fatigue Striation patterns on fracture cross-sections were analyzed. Compressive residual stresses and dense dislocation arrangements can be obtained in the superficial layer after LP. The influence of compressive residual stresses induced under different LP coverage rates on FCG properties was revealed. LP coverage rate had an apparent influence on FCG properties as confirmed by the Fatigue Striation spacing on fracture cross-sections. Moreover, FCG rate decreased with the increase of compressive residual stresses perpendicular to the crack growth direction, which indicated that LP had an obvious inhibitory effects on FCG.
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Effects of laser peening with different coverage areas on Fatigue crack growth properties of 6061-T6 aluminum alloy.
International Journal of Fatigue, 2013Co-Authors: Shu Huang, Jie Sheng, Meng Xiankai, Jianzhong Zhou, Kaiyu Luo, L D Zuo, Liming Dai, H.y. RuanAbstract:Abstract The effects of coverage area on Fatigue crack growth (FCG) properties of 6061-T6 aluminum alloy subject to multiple laser peening (LP) impacts were investigated. Residual stress, micro-structure and Fatigue Striation pattern on fracture cross-sections were analyzed. Compressive residual stresses and dense dislocation arrangements can be found in the superficial layer after LP. LP coverage area has a direct influence on FCG properties as verified by different size of shell ridges and Fatigue Striation spacing on fracture cross-sections. Meanwhile, FCG rate decreases with the increase of compressive residual stresses distribution perpendicular to the crack growth direction in the initial FCG stage.
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effect of repeated impacts on mechanical properties and Fatigue fracture morphologies of 6061 t6 aluminum subject to laser peening
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2012Co-Authors: Jianzhong Zhou, Jie Sheng, Shu Huang, H.y. Ruan, Changwen Wang, Kangmin Chen, H S ChenAbstract:Abstract The effect of repeated impacts on mechanical properties and Fatigue fracture morphologies of 6061-T6 aluminum subject to laser peening (LP) were investigated. Compared with the untreated samples, nano-hardness and Fatigue lives of the samples subjected to 1-3 LP impacts increased by 18.1–59.1% and 7.3–99.4%, respectively. Residual stress presented compressive state on the superficial layer of the samples after LP, and the value increased with the increase of the impact number. LP caused the location of Fatigue crack initiation (FCI) transferring from the top surface to sub-surface, and the distance from FCI to the top surface increased with the increase of the impact number. Meanwhile, the Fatigue Striation spacing (FSS) on the Fatigue crack growth (FCG) area decreased with the increase of the impact number. In addition, the enhancement mechanism of LP on the resistance of FCI and FCG were discussed.
Shu Huang - One of the best experts on this subject based on the ideXlab platform.
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Effect of laser peening with different energies on Fatigue fracture evolution of 6061-T6 aluminum alloy
Optics and Laser Technology, 2016Co-Authors: Jie Sheng, S. Q. Xu, J.z. Zhou, Shu Huang, J Z Lu, H F ZhangAbstract:To deeply understand the effect of laser peening (LP) with different laser pulse energies on 6061-T6 aluminum alloy, the Fatigue fracture morphologies evolution process at various Fatigue crack growth (FCG) stages and the corresponding strengthen mechanism were investigated. At the initial stage of FCG, more Fatigue micro-cliffs were found after LP, while the Fatigue Striation spacing simultaneously reduced. A "stop-continue" phenomenon of crack propagation was discovered for laser peened samples. The Fatigue Striation spacing at the middle stage of FCG increased significantly while compared with that at the initial stage, in addition, the Fatigue Striation spacing decreased with an increase in laser pulse energy. Fracture morphologies in transition region of laser peened samples exhibit a mixing fracture characteristic of Striations and dimples. The laser peened sample with laser pulse energy of 7 J presents more circuitous growing paths. Due to the complex stress state induced by LP, dimples with different sizes appeared in the final fracture region.
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effects of laser peening on residual stresses and Fatigue crack growth properties of ti 6al 4v titanium alloy
Optics and Lasers in Engineering, 2014Co-Authors: Jianzhong Zhou, Jie Sheng, Shu Huang, L D Zuo, Xiankai Meng, Q Tian, Y H Han, Weili ZhuAbstract:Abstract The effects of laser peening (LP) with different laser peening coverage rates on residual stresses and Fatigue crack growth (FCG) properties of Ti–6Al–4V titanium alloy were investigated. Residual stresses after LP and micro-structure with different Fatigue Striation patterns on fracture cross-sections were analyzed. Compressive residual stresses and dense dislocation arrangements can be obtained in the superficial layer after LP. The influence of compressive residual stresses induced under different LP coverage rates on FCG properties was revealed. LP coverage rate had an apparent influence on FCG properties as confirmed by the Fatigue Striation spacing on fracture cross-sections. Moreover, FCG rate decreased with the increase of compressive residual stresses perpendicular to the crack growth direction, which indicated that LP had an obvious inhibitory effects on FCG.
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Effects of laser peening with different coverage areas on Fatigue crack growth properties of 6061-T6 aluminum alloy.
International Journal of Fatigue, 2013Co-Authors: Shu Huang, Jie Sheng, Meng Xiankai, Jianzhong Zhou, Kaiyu Luo, L D Zuo, Liming Dai, H.y. RuanAbstract:Abstract The effects of coverage area on Fatigue crack growth (FCG) properties of 6061-T6 aluminum alloy subject to multiple laser peening (LP) impacts were investigated. Residual stress, micro-structure and Fatigue Striation pattern on fracture cross-sections were analyzed. Compressive residual stresses and dense dislocation arrangements can be found in the superficial layer after LP. LP coverage area has a direct influence on FCG properties as verified by different size of shell ridges and Fatigue Striation spacing on fracture cross-sections. Meanwhile, FCG rate decreases with the increase of compressive residual stresses distribution perpendicular to the crack growth direction in the initial FCG stage.
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effect of repeated impacts on mechanical properties and Fatigue fracture morphologies of 6061 t6 aluminum subject to laser peening
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2012Co-Authors: Jianzhong Zhou, Jie Sheng, Shu Huang, H.y. Ruan, Changwen Wang, Kangmin Chen, H S ChenAbstract:Abstract The effect of repeated impacts on mechanical properties and Fatigue fracture morphologies of 6061-T6 aluminum subject to laser peening (LP) were investigated. Compared with the untreated samples, nano-hardness and Fatigue lives of the samples subjected to 1-3 LP impacts increased by 18.1–59.1% and 7.3–99.4%, respectively. Residual stress presented compressive state on the superficial layer of the samples after LP, and the value increased with the increase of the impact number. LP caused the location of Fatigue crack initiation (FCI) transferring from the top surface to sub-surface, and the distance from FCI to the top surface increased with the increase of the impact number. Meanwhile, the Fatigue Striation spacing (FSS) on the Fatigue crack growth (FCG) area decreased with the increase of the impact number. In addition, the enhancement mechanism of LP on the resistance of FCI and FCG were discussed.
Jie Sheng - One of the best experts on this subject based on the ideXlab platform.
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Effect of laser peening with different energies on Fatigue fracture evolution of 6061-T6 aluminum alloy
Optics and Laser Technology, 2016Co-Authors: Jie Sheng, S. Q. Xu, J.z. Zhou, Shu Huang, J Z Lu, H F ZhangAbstract:To deeply understand the effect of laser peening (LP) with different laser pulse energies on 6061-T6 aluminum alloy, the Fatigue fracture morphologies evolution process at various Fatigue crack growth (FCG) stages and the corresponding strengthen mechanism were investigated. At the initial stage of FCG, more Fatigue micro-cliffs were found after LP, while the Fatigue Striation spacing simultaneously reduced. A "stop-continue" phenomenon of crack propagation was discovered for laser peened samples. The Fatigue Striation spacing at the middle stage of FCG increased significantly while compared with that at the initial stage, in addition, the Fatigue Striation spacing decreased with an increase in laser pulse energy. Fracture morphologies in transition region of laser peened samples exhibit a mixing fracture characteristic of Striations and dimples. The laser peened sample with laser pulse energy of 7 J presents more circuitous growing paths. Due to the complex stress state induced by LP, dimples with different sizes appeared in the final fracture region.
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effects of laser peening on residual stresses and Fatigue crack growth properties of ti 6al 4v titanium alloy
Optics and Lasers in Engineering, 2014Co-Authors: Jianzhong Zhou, Jie Sheng, Shu Huang, L D Zuo, Xiankai Meng, Q Tian, Y H Han, Weili ZhuAbstract:Abstract The effects of laser peening (LP) with different laser peening coverage rates on residual stresses and Fatigue crack growth (FCG) properties of Ti–6Al–4V titanium alloy were investigated. Residual stresses after LP and micro-structure with different Fatigue Striation patterns on fracture cross-sections were analyzed. Compressive residual stresses and dense dislocation arrangements can be obtained in the superficial layer after LP. The influence of compressive residual stresses induced under different LP coverage rates on FCG properties was revealed. LP coverage rate had an apparent influence on FCG properties as confirmed by the Fatigue Striation spacing on fracture cross-sections. Moreover, FCG rate decreased with the increase of compressive residual stresses perpendicular to the crack growth direction, which indicated that LP had an obvious inhibitory effects on FCG.
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Effects of laser peening with different coverage areas on Fatigue crack growth properties of 6061-T6 aluminum alloy.
International Journal of Fatigue, 2013Co-Authors: Shu Huang, Jie Sheng, Meng Xiankai, Jianzhong Zhou, Kaiyu Luo, L D Zuo, Liming Dai, H.y. RuanAbstract:Abstract The effects of coverage area on Fatigue crack growth (FCG) properties of 6061-T6 aluminum alloy subject to multiple laser peening (LP) impacts were investigated. Residual stress, micro-structure and Fatigue Striation pattern on fracture cross-sections were analyzed. Compressive residual stresses and dense dislocation arrangements can be found in the superficial layer after LP. LP coverage area has a direct influence on FCG properties as verified by different size of shell ridges and Fatigue Striation spacing on fracture cross-sections. Meanwhile, FCG rate decreases with the increase of compressive residual stresses distribution perpendicular to the crack growth direction in the initial FCG stage.
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effect of repeated impacts on mechanical properties and Fatigue fracture morphologies of 6061 t6 aluminum subject to laser peening
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2012Co-Authors: Jianzhong Zhou, Jie Sheng, Shu Huang, H.y. Ruan, Changwen Wang, Kangmin Chen, H S ChenAbstract:Abstract The effect of repeated impacts on mechanical properties and Fatigue fracture morphologies of 6061-T6 aluminum subject to laser peening (LP) were investigated. Compared with the untreated samples, nano-hardness and Fatigue lives of the samples subjected to 1-3 LP impacts increased by 18.1–59.1% and 7.3–99.4%, respectively. Residual stress presented compressive state on the superficial layer of the samples after LP, and the value increased with the increase of the impact number. LP caused the location of Fatigue crack initiation (FCI) transferring from the top surface to sub-surface, and the distance from FCI to the top surface increased with the increase of the impact number. Meanwhile, the Fatigue Striation spacing (FSS) on the Fatigue crack growth (FCG) area decreased with the increase of the impact number. In addition, the enhancement mechanism of LP on the resistance of FCI and FCG were discussed.
Chow-shing Shin - One of the best experts on this subject based on the ideXlab platform.
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Cyclic Fatigue behavior of nickel-titanium dental rotary files in clinical simulated root canals.
Journal of the Formosan Medical Association, 2017Co-Authors: Chih-wen Chi, Chun-pin Lin, Chow-shing ShinAbstract:Background/purpose Dental rotary instruments can be applied in multiple conditions of canals, but unpredictable Fatigue fracture may happen. This study evaluated the Fatigue lives of two batches of nickel–titanium (NiTi) dental rotary files operating in clinically simulated root canals. Methods Single-step cyclic Fatigue tests were carried out to assess the performance of two batches of NiTi files (ProTaper and ProFile) in nine combinations of simulated canals (cylinder radii 5 mm, 7.5 mm, and 10 mm, and insertion angles 20°, 40°, and 60°). Two-step cyclic Fatigue tests were carried out in simulated root canals with the same radius by using the following two sets of insertion angles: (20°, 40°), (20°, 60°), (40°, 20°), and (60°, 20°). Fracture surfaces were observed by scanning electron microscopy. Results The single-step cyclic Fatigue results showed that cyclic Fatigue lives of the files decreased with increasing insertion angles or decreasing cylinder radius. The ProFile #25 .04 file was more Fatigue resistant than the ProTaper F2 file. In two-step cyclic Fatigue tests, the total Fatigue lives were usually more than 100% when the files operated at a lower strain and then at a higher strain. By scanning electron microscopy, a larger area of Fatigue Striation corresponded to a longer Fatigue life. Conclusion Cyclic Fatigue life can be influenced by the strains and geometries of files. The Fatigue life was prolonged when the files operated at a lower strain and then at a higher strain. However, the Fatigue life was shortened if the loading sequence was reversed.
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Cyclic Fatigue behavior of nickel–titanium dental rotary files in clinical simulated root canals
Elsevier, 2017Co-Authors: Chih-wen Chi, Chun-pin Lin, Chow-shing ShinAbstract:Dental rotary instruments can be applied in multiple conditions of canals, but unpredictable Fatigue fracture may happen. This study evaluated the Fatigue lives of two batches of nickel–titanium (NiTi) dental rotary files operating in clinically simulated root canals. Methods: Single-step cyclic Fatigue tests were carried out to assess the performance of two batches of NiTi files (ProTaper and ProFile) in nine combinations of simulated canals (cylinder radii 5 mm, 7.5 mm, and 10 mm, and insertion angles 20°, 40°, and 60°). Two-step cyclic Fatigue tests were carried out in simulated root canals with the same radius by using the following two sets of insertion angles: (20°, 40°), (20°, 60°), (40°, 20°), and (60°, 20°). Fracture surfaces were observed by scanning electron microscopy. Results: The single-step cyclic Fatigue results showed that cyclic Fatigue lives of the files decreased with increasing insertion angles or decreasing cylinder radius. The ProFile #25 .04 file was more Fatigue resistant than the ProTaper F2 file. In two-step cyclic Fatigue tests, the total Fatigue lives were usually more than 100% when the files operated at a lower strain and then at a higher strain. By scanning electron microscopy, a larger area of Fatigue Striation corresponded to a longer Fatigue life. Conclusion: Cyclic Fatigue life can be influenced by the strains and geometries of files. The Fatigue life was prolonged when the files operated at a lower strain and then at a higher strain. However, the Fatigue life was shortened if the loading sequence was reversed
Weili Zhu - One of the best experts on this subject based on the ideXlab platform.
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effects of laser peening on residual stresses and Fatigue crack growth properties of ti 6al 4v titanium alloy
Optics and Lasers in Engineering, 2014Co-Authors: Jianzhong Zhou, Jie Sheng, Shu Huang, L D Zuo, Xiankai Meng, Q Tian, Y H Han, Weili ZhuAbstract:Abstract The effects of laser peening (LP) with different laser peening coverage rates on residual stresses and Fatigue crack growth (FCG) properties of Ti–6Al–4V titanium alloy were investigated. Residual stresses after LP and micro-structure with different Fatigue Striation patterns on fracture cross-sections were analyzed. Compressive residual stresses and dense dislocation arrangements can be obtained in the superficial layer after LP. The influence of compressive residual stresses induced under different LP coverage rates on FCG properties was revealed. LP coverage rate had an apparent influence on FCG properties as confirmed by the Fatigue Striation spacing on fracture cross-sections. Moreover, FCG rate decreased with the increase of compressive residual stresses perpendicular to the crack growth direction, which indicated that LP had an obvious inhibitory effects on FCG.
