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J C Williams - One of the best experts on this subject based on the ideXlab platform.
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influence of hydrogen on dwell Fatigue Response of near alpha titanium alloys
Acta Materialia, 2020Co-Authors: V Sinha, R B Schwarz, M J Mills, J C WilliamsAbstract:Abstract The prior studies have investigated the influence of internal hydrogen on dwell-Fatigue behavior of near-α titanium alloys primarily in the lamellar microstructural condition. In the current study, the effects of internal hydrogen, in the range 10–230 ppm (by weight), on the dwell-Fatigue behavior of Ti-6242Si alloy were investigated. The examined alloy had a bimodal microstructure comprising approximately 70 vol% primary α grains and 30 vol% transformed β regions. The dwell-Fatigue life generally increased with increasing hydrogen content. The dwell-Fatigue lives were longer by a factor of as high as 6 for high (≥150 ppm) hydrogen contents than for the low ( 150 ppm) hydrogen contents. Specifically, these facets were inclined at ∼8 – 17° from the basal plane. Therefore, the longer dwell-Fatigue lives observed for the alloys with hydrogen contents ≥150 ppm could not be explained on the basis of any differences in crystallography of the facets at crack-initiation sites. The longer dwell-Fatigue lives for higher hydrogen contents can be explained within the framework of time-dependent load shedding from the soft microtextured regions (MTRs) to the hard MTRs if the local stress redistribution at the soft MTR/hard MTR boundary due to the hold at maximum load is reduced with increasing hydrogen content.
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effects of hydrogen on Fatigue behavior of near alpha titanium alloys
Scripta Materialia, 2018Co-Authors: V Sinha, R B Schwarz, M J Mills, J C WilliamsAbstract:Abstract The influence of hydrogen content on Fatigue Response was examined for a near-α titanium alloy, Ti-6Al-2Sn-4Zr-2Mo-0.1Si, in bimodal microstructural condition with ~70 vol% primary α. The hydrogen content was varied in the range 7–127 ppm (by weight). The fracture mechanism at crack-initiation sites changed from ductile tearing with localized plasticity in low (
V Sinha - One of the best experts on this subject based on the ideXlab platform.
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influence of hydrogen on dwell Fatigue Response of near alpha titanium alloys
Acta Materialia, 2020Co-Authors: V Sinha, R B Schwarz, M J Mills, J C WilliamsAbstract:Abstract The prior studies have investigated the influence of internal hydrogen on dwell-Fatigue behavior of near-α titanium alloys primarily in the lamellar microstructural condition. In the current study, the effects of internal hydrogen, in the range 10–230 ppm (by weight), on the dwell-Fatigue behavior of Ti-6242Si alloy were investigated. The examined alloy had a bimodal microstructure comprising approximately 70 vol% primary α grains and 30 vol% transformed β regions. The dwell-Fatigue life generally increased with increasing hydrogen content. The dwell-Fatigue lives were longer by a factor of as high as 6 for high (≥150 ppm) hydrogen contents than for the low ( 150 ppm) hydrogen contents. Specifically, these facets were inclined at ∼8 – 17° from the basal plane. Therefore, the longer dwell-Fatigue lives observed for the alloys with hydrogen contents ≥150 ppm could not be explained on the basis of any differences in crystallography of the facets at crack-initiation sites. The longer dwell-Fatigue lives for higher hydrogen contents can be explained within the framework of time-dependent load shedding from the soft microtextured regions (MTRs) to the hard MTRs if the local stress redistribution at the soft MTR/hard MTR boundary due to the hold at maximum load is reduced with increasing hydrogen content.
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effects of hydrogen on Fatigue behavior of near alpha titanium alloys
Scripta Materialia, 2018Co-Authors: V Sinha, R B Schwarz, M J Mills, J C WilliamsAbstract:Abstract The influence of hydrogen content on Fatigue Response was examined for a near-α titanium alloy, Ti-6Al-2Sn-4Zr-2Mo-0.1Si, in bimodal microstructural condition with ~70 vol% primary α. The hydrogen content was varied in the range 7–127 ppm (by weight). The fracture mechanism at crack-initiation sites changed from ductile tearing with localized plasticity in low (
Adam T. Clare - One of the best experts on this subject based on the ideXlab platform.
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The influence of shot peening on the Fatigue Response of Ti-6Al-4V surfaces subject to different machining processes
International Journal of Fatigue, 2018Co-Authors: Zhengkai Xu, J. Dunleavey, M. Antar, Richard Hood, G. Kucukturk, Christopher J. Hyde, Adam T. ClareAbstract:Machining processes are known to drastically impact the performance and lifetime of a component subjected to Fatigue in service. Therefore, understanding the effect of manufacturing processes on surface integrity is vital to determine their suitability for any given application. As part of a wider study investigating multiple production operations, results are presented here which characterise the Fatigue performance and failure mechanisms of Ti-6Al-4V specimens subject to conventional (end milling, surface grinding) and non-conventional machining processes (abrasive waterjet machining, wire electrical discharge machining, large area electron beam melting). Post process shot peening was then applied on each of the 5 different surfaces generated and the resulting Fatigue Response similarly evaluated. The abrasive waterjet machined specimens generally exhibited the longest Fatigue life, particularly at higher applied stress (≥ 700 MPa) irrespective of surface condition. Despite the difference in process mechanisms, Fatigue results for the milled and wire electrical discharge machined surfaces were comparable. Examination of the Fatigue specimen fracture surfaces however, revealed that the locations of crack initiation were inconsistent for the different processes and conditions assessed. In general, post process shot peening increased the Fatigue strength/life of all the evaluated specimens, regardless of the base machining operation.
Meslet Alhajri - One of the best experts on this subject based on the ideXlab platform.
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the Fatigue and final fracture behavior of sic particle reinforced 7034 aluminum matrix composites
Composites Part B-engineering, 2002Co-Authors: T S Srivatsan, Meslet AlhajriAbstract:Abstract In this research paper, the cyclic stress-amplitude-controlled Fatigue Response and fracture behavior of aluminum alloy 7034 discontinuously reinforced with silicon carbide particulates (SiCp) is presented. In view of the limited ambient temperature ductility, test specimens of the 7034/SiCp composite, in both the under-aged and peak-aged conditions, were cyclically deformed under stress-amplitude-control at an elevated temperature corresponding to the aging temperature of the alloy. The cyclic Fatigue tests were conducted at two different load ratios with the objective of documenting the conjoint influences of intrinsic composite microstructural effects, nature of loading, and magnitude of cyclic stress amplitude on cyclic Fatigue life and fracture characteristics. The final fracture behavior of the composite is discussed in light of the concurrent and mutually interactive influences of composite microstructural effects, deformation characteristics of the composite constituents, nature of loading, and resultant Fatigue life.
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influence of silicon carbide particulate reinforcement on quasi static and cyclic Fatigue fracture behavior of 6061 aluminum alloy composites
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2002Co-Authors: T S Srivatsan, Meslet Alhajri, M Petraroli, Bruce A Hotton, Paul C LamAbstract:In this paper, the quasi-static and cyclic Fatigue fracture behavior of aluminum alloy 6061 discontinuously-reinforced with fine particulates of silicon carbide are presented and discussed. The discontinuous particulate-reinforced 6061 aluminum alloy was cyclically deformed to failure at ambient temperature under stress-amplitude controlled conditions. The influence of volume fraction of particulate reinforcement on high cycle Fatigue Response is presented. The underlying mechanisms governing the fracture behavior during quasi-static and cyclic Fatigue deformation are discussed and rationalized in light of concurrent and mutually interactive influences of composite microstructural features, deformation characteristics of the metal matrix and reinforcement particulate, nature of loading and ductility of the microstructure.
M J Mills - One of the best experts on this subject based on the ideXlab platform.
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influence of hydrogen on dwell Fatigue Response of near alpha titanium alloys
Acta Materialia, 2020Co-Authors: V Sinha, R B Schwarz, M J Mills, J C WilliamsAbstract:Abstract The prior studies have investigated the influence of internal hydrogen on dwell-Fatigue behavior of near-α titanium alloys primarily in the lamellar microstructural condition. In the current study, the effects of internal hydrogen, in the range 10–230 ppm (by weight), on the dwell-Fatigue behavior of Ti-6242Si alloy were investigated. The examined alloy had a bimodal microstructure comprising approximately 70 vol% primary α grains and 30 vol% transformed β regions. The dwell-Fatigue life generally increased with increasing hydrogen content. The dwell-Fatigue lives were longer by a factor of as high as 6 for high (≥150 ppm) hydrogen contents than for the low ( 150 ppm) hydrogen contents. Specifically, these facets were inclined at ∼8 – 17° from the basal plane. Therefore, the longer dwell-Fatigue lives observed for the alloys with hydrogen contents ≥150 ppm could not be explained on the basis of any differences in crystallography of the facets at crack-initiation sites. The longer dwell-Fatigue lives for higher hydrogen contents can be explained within the framework of time-dependent load shedding from the soft microtextured regions (MTRs) to the hard MTRs if the local stress redistribution at the soft MTR/hard MTR boundary due to the hold at maximum load is reduced with increasing hydrogen content.
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effects of hydrogen on Fatigue behavior of near alpha titanium alloys
Scripta Materialia, 2018Co-Authors: V Sinha, R B Schwarz, M J Mills, J C WilliamsAbstract:Abstract The influence of hydrogen content on Fatigue Response was examined for a near-α titanium alloy, Ti-6Al-2Sn-4Zr-2Mo-0.1Si, in bimodal microstructural condition with ~70 vol% primary α. The hydrogen content was varied in the range 7–127 ppm (by weight). The fracture mechanism at crack-initiation sites changed from ductile tearing with localized plasticity in low (
