The Experts below are selected from a list of 9024 Experts worldwide ranked by ideXlab platform
H J Maier - One of the best experts on this subject based on the ideXlab platform.
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on the mechanical behaviour of titanium alloy tial6v4 manufactured by selective laser melting fatigue resistance and crack growth performance
International Journal of Fatigue, 2013Co-Authors: Stefan Leuders, Thomas Niendorf, Miriam Thöne, Andre Riemer, Thomas Troster, Hans Albert Richard, H J MaierAbstract:Abstract Direct manufacturing (DM), also referred to as additive manufacturing or additive layer manufacturing, has recently gained a lot of interest due to the feasibility of producing light-weight metallic components directly from design data. Selective laser melting is a very promising DM technique for providing near net shape components with relative high surface quality and bulk density. Still, process induced imperfections, i.e. micron sized pores and residual stresses upon processing, need to be considered for future application, e.g. in the aerospace and biomedical sectors. Moreover, fatigue loading is a critical scenario for such components and needs to be investigated thoroughly. Consequently, the current study aims at establishing sound Microstructure–Defect–property relationships under cyclic loading for a TiAl6V4 alloy processed by selective laser melting. Employing mechanical testing, hot isostatic pressing, electron microscopy and computer tomography it is shown that the micron sized pores mainly affect fatigue strength, while residual stresses have a strong impact on fatigue crack growth.
Alessandro Fortunato - One of the best experts on this subject based on the ideXlab platform.
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Effect of selective laser melting (SLM) process parameters on Microstructure and mechanical properties of 316L austenitic stainless steel
Journal of Materials Processing Technology, 2017Co-Authors: Erica Liverani, Stefania Toschi, Lorella Ceschini, Alessandro FortunatoAbstract:Metal components produced via selective laser melting (SLM) additive manufacturing (AM) can offer comparable and sometimes superior mechanical properties to those of bulk materials. Selection of the appropriate process parameters (e.g. laser power, build direction, scan hatch spacing) plays a fundamental role in determining final properties. For this reason, Microstructure, Defect formation and mechanical properties of AISI 316L components are investigated in this paper according to the process parameters used for their fabrication. A first experimental campaign establishes process parameters guaranteeing a density greater than 98%. Samples for microstructural and mechanical characterization are then produced based on these results, varying laser power from 100 W to 150 W, hatch space from 0.05 mm to 0.07 mm and orientation from 45° to 90°. A MYSINT100 SLM machine with laser power up to 150 W and spot diameter of 50 μm is employed for all experiments. The presented results establish a correlation between the process parameters and the resulting Microstructure and mechanical properties of SLM 316L specimens.
Binshi Xu - One of the best experts on this subject based on the ideXlab platform.
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Progress and Challenges of Ultrasonic Testing for Stress in Remanufacturing Laser Cladding Coating
Materials, 2018Co-Authors: Shiyun Dong, Binshi XuAbstract:Stress in laser cladding coating is an important factor affecting the safe operation of remanufacturing components. Ultrasonic testing has become a popular approach in the nondestructive evaluation of stress, because it has the advantages of safety, nondestructiveness, and online detection. This paper provides a review of ultrasonic testing for stress in remanufacturing laser cladding coating. It summarizes the recent research outcomes on ultrasonic testing for stress, and analyzes the mechanism of ultrasonic testing for stress. Remanufacturing laser cladding coating shows typical anisotropic behaviors. The ultrasonic testing signal in laser cladding coating is influenced by many complex factors, such as Microstructure, Defect, temperature, and surface roughness, among others. At present, ultrasonic testing for stress in laser cladding coating can only be done roughly. This paper discusses the active mechanism of micro/macro factors in the reliability of stress measurement, as well as the impact of stress measurement on the quality and safety of remanufacturing components. Based on the discussion, this paper proposes strategies to nondestructively, rapidly, and accurately measure stress in remanufacturing laser cladding coating.
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Progresses and Challenges of Ultrasonic Testing for Stress in Remanufacturing Laser Cladding Coating
2018Co-Authors: Shiyun Dong, Binshi XuAbstract:Stess in laser cladding coating is an important factor affecting the safe operation of remanufacturing components. Ultrasonic testing has become a hot direction in nondestructive evaluation of stress, because it has the advantages of safety, non-destructive and on-line detection. This paper provides a review of ultrasonic testing for stress in remanufacturing laser cladding coating. It summarizes the recent research outcomes on ultrasonic testing for stress, analyzes mechanism of ultrasonic testing for stress. Remanufacturing laser cladding coating shows typical anisotropic behaviors, the ultrasonic testing signal in laser cladding coating is influenced by many complex factors, such as Microstructure, Defect, temperature and surface roughness, etc. At present, ultrasonic testing for stress in laser cladding coating can only be done roughly. The paper discusses active mechanism of micro / macro factors to the reliability of stress measurement and the impact of stress measurement to the quality and safety of remanufacturing components. Base on the discussion, the paper proposes strategies for acquisition of nondestructive, rapid and accurate measurement of stress in remanufacturing laser cladding coating.
Nam Phan - One of the best experts on this subject based on the ideXlab platform.
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fatigue of additive manufactured ti 6al 4v part ii the relationship between Microstructure material cyclic properties and component performance
International Journal of Fatigue, 2020Co-Authors: Reza Molaei, Nima Shamsaei, Ali Fatemi, Niloofar Sanaei, Jonathan W Pegues, Shuai Shao, P Li, D H Warner, Nam PhanAbstract:Abstract Part I of these two-part paper series focused on the process and structure relationships, effect of powder feedstock, fabrication parameters, and post fabrication treatments on the resulting Microstructure, Defect characteristics, and surface quality of the fabricated Ti-6Al-4V parts. This second part extends the study by evaluating the effect of the aforementioned factors on axial, torsion, and multiaxial fatigue behavior of the additively manufactured (AM) Ti-6Al-4V specimens. Despite the advantages of additive manufacturing techniques discussed in Part I, they are still rarely used in fatigue critical load carrying applications, partly due to insufficient understanding of fatigue behavior and its dependence on variations in material Microstructure and Defects. This becomes even more challenging when other process characteristics of AM including build orientation, residual stresses, and surface roughness are considered. This paper discusses these effects, as well as machine-to-machine variability and the effects of specimen geometry and size, post heat treatment, and multiaxial stress state. Experimental uniaxial, torsion, and multiaxial fatigue test results recently generated by the authors for laser beam powder bed fusion- produced Ti-6Al-4V alloy are reviewed. The observed behaviors and the influence of the aforementioned effects are then related to the resulting Microstructure and Defect characteristics discussed in Part I. Fatigue life prediction results for specimens based on the effective Defect size calculated by extreme value statistics (EVS) of the internal Defects and surface roughness are also presented and compared with experimental data. The observed behaviors and specimen test results are then used for fatigue life analysis and predictions of a link component as an illustrative application example.
Stefan Leuders - One of the best experts on this subject based on the ideXlab platform.
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on the mechanical behaviour of titanium alloy tial6v4 manufactured by selective laser melting fatigue resistance and crack growth performance
International Journal of Fatigue, 2013Co-Authors: Stefan Leuders, Thomas Niendorf, Miriam Thöne, Andre Riemer, Thomas Troster, Hans Albert Richard, H J MaierAbstract:Abstract Direct manufacturing (DM), also referred to as additive manufacturing or additive layer manufacturing, has recently gained a lot of interest due to the feasibility of producing light-weight metallic components directly from design data. Selective laser melting is a very promising DM technique for providing near net shape components with relative high surface quality and bulk density. Still, process induced imperfections, i.e. micron sized pores and residual stresses upon processing, need to be considered for future application, e.g. in the aerospace and biomedical sectors. Moreover, fatigue loading is a critical scenario for such components and needs to be investigated thoroughly. Consequently, the current study aims at establishing sound Microstructure–Defect–property relationships under cyclic loading for a TiAl6V4 alloy processed by selective laser melting. Employing mechanical testing, hot isostatic pressing, electron microscopy and computer tomography it is shown that the micron sized pores mainly affect fatigue strength, while residual stresses have a strong impact on fatigue crack growth.