The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Ali Fatemi - One of the best experts on this subject based on the ideXlab platform.
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Defects in additive manufactured metals and their effect on Fatigue Performance: A state-of-the-art review
Progress in Materials Science, 2020Co-Authors: Niloofar Sanaei, Ali FatemiAbstract:Abstract Additive manufacturing (AM) is emerging as an alternative to conventional subtractive manufacturing methods with the goal to deliver unique and complex net or near-net shaped parts. AM components should operate under various loading conditions, from static to complex dynamic multiaxial loadings, therefor, Fatigue Performance is often a key consideration. Intrinsic AM defects such as Lack of Fusion (LOF) defects, porosities, and un-melted particles are important for Fatigue as a local phenomenon which usually starts at stress concentrations. Defects can be minimized by process optimization and/or post-processing but may not be fully eliminated. Full-scale testing, which is typically very costly and often necessary to assess reliability for Fatigue Performance of safety critical components, could be reduced by robust analytical Fatigue Performance prediction techniques. This work reviews the literature on the influential microstructural attributes on Fatigue Performance of AM parts with a focus on generated defects. This includes AM defect characterization and statistical analysis methods, as well as effect of process parameters and post-processing on defects, and consequently Fatigue Performance. The review also includes defect-based, microstructure-sensitive, and multiscale models proposed in the literature for modeling the effect of defects on Fatigue Performance and provides an outlook for additional research needed.
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critical assessment of the Fatigue Performance of additively manufactured ti 6al 4v and perspective for future research
International Journal of Fatigue, 2016Co-Authors: D H Warner, Ali Fatemi, Nam PhanAbstract:Abstract To realize the potential benefits of additive manufacturing technology in airframe and ground vehicle applications, the Fatigue Performance of load bearing additively manufactured materials must be understood. Due to the novelty of this rapidly developing technology, a very limited, yet swiftly evolving literature exists on the topic. Motivated by these two points, we have attempted to catalog and analyze the published Fatigue Performance data of an additively manufactured alloy of significant technological interest, Ti–6Al–4V. Focusing on uniaxial Fatigue Performance, we compare to traditionally manufactured Ti–6Al–4V, discussing failure mechanisms, defects, microstructure, and processing parameters. We then attempt to identify key knowledge gaps that must be addressed before AM technology can safely and effectively be employed in critical load bearing applications.
Nam Phan - One of the best experts on this subject based on the ideXlab platform.
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critical assessment of the Fatigue Performance of additively manufactured ti 6al 4v and perspective for future research
International Journal of Fatigue, 2016Co-Authors: D H Warner, Ali Fatemi, Nam PhanAbstract:Abstract To realize the potential benefits of additive manufacturing technology in airframe and ground vehicle applications, the Fatigue Performance of load bearing additively manufactured materials must be understood. Due to the novelty of this rapidly developing technology, a very limited, yet swiftly evolving literature exists on the topic. Motivated by these two points, we have attempted to catalog and analyze the published Fatigue Performance data of an additively manufactured alloy of significant technological interest, Ti–6Al–4V. Focusing on uniaxial Fatigue Performance, we compare to traditionally manufactured Ti–6Al–4V, discussing failure mechanisms, defects, microstructure, and processing parameters. We then attempt to identify key knowledge gaps that must be addressed before AM technology can safely and effectively be employed in critical load bearing applications.
M Ramulu - One of the best experts on this subject based on the ideXlab platform.
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Fatigue Performance evaluation of selective laser melted ti 6al 4v
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2014Co-Authors: Paul D Edwards, M RamuluAbstract:Abstract Additive Manufacturing of titanium components holds promise to deliver benefits such as reduced cost, weight and carbon emissions during both manufacture and use. To capitalize on these benefits, it must be shown that the mechanical Performance of parts produced by Additive Manufacturing can meet design requirements that are typically based on wrought material Performance properties. Of particular concern for safety critical structures are the Fatigue properties of parts produced by Additive Manufacturing. This research evaluates the Fatigue properties of Ti–6Al–4V specimens produced by the Selective Laser Melting additive manufacturing process. It was found that the Fatigue life is significantly lower compared to wrought material. This reduction in Fatigue Performance was attributed to a variety of issues, such as microstructure, porosity, surface finish and residual stress. There was also found to be a high degree of anisotropy in the Fatigue Performance associated with the specimen build orientation.
K.j. Stevens - One of the best experts on this subject based on the ideXlab platform.
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Fatigue Performance and microanalysis of heat treated 2205 duplex stainless steel
Materials Science and Technology, 1999Co-Authors: K.j. StevensAbstract:The reduced corrosion Fatigue Performance of a heat treated grade of duplex SAF 2205 stainless steel has been quantified using Wohler rotating bending Fatigue machines. The reduction in Fatigue Performance has been related to elemental profiles around intergranular and intragranular precipitates and grain boundary segregation measured using EDAX analysis and scanning transmission electron microscopy.
Zhanqiang Liu - One of the best experts on this subject based on the ideXlab platform.
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Surface integrity and Fatigue Performance of 17-4PH stainless steel after cutting operations
Surface and Coatings Technology, 2016Co-Authors: Guoliang Liu, Xiangyu Wang, Bin Zou, Chuanzhen Huang, Zhanqiang LiuAbstract:The 17-4PH stainless steel has been applied as a substitute of titanium to make jet engine parts, and Fatigue life of the machined surfaces are very important due to its high reliability and safety demand. In this work, a series of experiments were conducted to investigate the impact of the cutting operations on the surface integrity, and its further influence on the Fatigue life. It was confirmed that the Fatigue Performance of the machined surface was determined by the interactions of the surface integrity characteristics, including the work hardening, surface roughness and residual stress field. The softened layer under the machined surface and the compressive residual stress field were generated under all cutting conditions, resulting in the improved Fatigue life when compared to the polished specimens. The plastic deformation and the resulting work hardening on the machined surface were enhanced continuously with an increase in each of the cutting parameters, which could cause significant decrease of the Fatigue Performance of the workpiece. The influence of surface roughness on the Fatigue Performance could be overshadowed by other surface integrity characteristics, since its effect was weakened by the curved feed marks generated on the face-milled surfaces. The cutting parameters could influence the Fatigue Performance of the machined components significantly by changing their surface integrity.
