The Experts below are selected from a list of 18168 Experts worldwide ranked by ideXlab platform
Lijun Song - One of the best experts on this subject based on the ideXlab platform.
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phase congruency melt pool edge extraction for Laser Additive Manufacturing
Journal of Materials Processing Technology, 2017Co-Authors: Lijun Song, Fanghua Wang, Xu HanAbstract:Abstract Melt pool geometry, as one of the most important built attributes that reflect the stability of an Additive Manufacturing process, has been widely used for process monitoring and process control. Currently, intensity-based gray-level image processing is generally used to extract the melt pool boundaries. However, selection of proper threshold is challenging due to the intensity-related noise and disturbance from blurred areas, flares and speckles. This paper presents a phase congruency melt pool edge extraction approach that performs well for phase-invariant but intensity-variant image boundary extraction. The results show that the phase congruency edge extraction approach can not only robustly handle disturbances from blurred areas, flares, black areas and incandescent droplets, but also obtain more accurate melt pool geometries. A real-time melt pool monitoring system is developed to monitor a geometrically dependent and time varying melt pool evolution during an Additive Manufacturing process.
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Melt-pool motion, temperature variation and dendritic morphology of Inconel 718 during pulsed- and continuous-wave Laser Additive Manufacturing: A comparative study
Materials and Design, 2017Co-Authors: Simeng Li, Keyang Liu, Wenjia Xiao, Yanqin Li, Xu Han, Jyoti Mazumder, Lijun SongAbstract:Pulsed-wave Laser Additive Manufacturing offers a number of advantages, such as a lower heat accumulation, a higher cooling rate, finer microstructures and improved mechanical properties over continuous-wave Laser Additive Manufacturing. However, how pulsed Laser acts on the melt pool motion, thermal field and hence microstructure is not clear. In this work, a three-dimensional transport model utilizing the level set method is developed to simulate the transient melt pool motion, heat/mass transfer and fluid flow for pulsed-wave Laser Additive Manufacturing. A boundary restriction on the fluid velocity along the liquid/gas interface is employed to confine the liquid flow within the melt pool. The simulated melt pool geometry and temperature are compared with experimental measurements. Moreover, melt pool geometry/motion, temperature variation, and their influence on the microstructure of fabricated samples using both pulsed- and continuous-wave Lasers are analyzed. It is found that pulsed-wave Laser Additive Manufacturing features a rounder shaped melt pool, a periodically heartbeat-like motion of the melt pool and a doubled cooling rate. The higher tilt angle of the solidification front results in a dendrite growth direction more tilted to the Laser scanning direction and the higher cooling rate results in finer columnar dendrites.
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Laves phase control of Inconel 718 alloy using quasi-continuous-wave Laser Additive Manufacturing
Materials and Design, 2017Co-Authors: H. Xiao, Simeng Li, Xu Han, Jyoti Mazumder, Lijun SongAbstract:Nb segregation and Laves phase formation are known to be detrimental to mechanical properties of Inconel 718. However, effective efforts to suppress Nb segregation and Laves phase formation are still lacking. In this work, a quasi-continuous-wave (QCW) Laser Additive Manufacturing (LAM) is used to control Nb segregation and Laves phase formation. Thermal behaviors of the molten pool, microstructural evolution and mechanical response of the fabricated samples to aging treatment were investigated. Compared to continuous wave (CW) LAM, QCW-LAM results in a refined and equiaxed dendrite microstructure, a reduced Nb segregation, and attended fine and discrete Laves phase particles, due to an improved cooling rate with one order of magnitude and a decreased solidification time of the molten pool. In addition, the QCW sample shows a good response to aging treatment with a higher hardness and more desired tensile properties due to the reduced Nb segregation, the obtained fine discrete Laves phase and the refined dendrite microstructure. The tensile strength (~ 1404.1 MPa), the yield strength (~ 1120.6 MPa) and the ductility (~ 12.4 pct) of the aged QCW sample are higher than the ASTM limits of the wrought Inconel 718 alloy.
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Real-Time Composition Monitoring Using Support Vector Regression of Laser-Induced Plasma for Laser Additive Manufacturing
IEEE Transactions on Industrial Electronics, 2017Co-Authors: Lijun Song, Wenkang Huang, Jyoti MazumderAbstract:Laser Additive Manufacturing has gained widespread adoption in recent years. However, process diagnosis and process control lag behind the progresses of other key technologies, which make the product quality control a challenging problem. This work proposes an operating parameter conditioned support vector regression (SVR) method that uses processing parameter conditioned kernel function to achieve a processing parameter independent in-situ composition prediction. Two different features of Laser-induced plasma, spectral line-intensity-ratio, and both spectral line-intensity-ratio and spectral integrated intensity were used to train the SVR. Composition measurements using a calibration curve method, partial least square regression, and artificial neural networks are also performed for comparison. The results show that the SVR with both spectral line-intensity-ratio and spectral integrated intensity as inputs has the best performance due to linearly separable point clusters in the high-dimensional space. Laser power independent composition prediction is achieved and real-time composition predictions are validated. It is proved that the operating parameter conditioned SVR provides a more accurate, a more universal, and an operating parameter independent prediction. Moreover, operating parameter conditioned SVR provides a potential data-driven-based approach for real-time composition monitoring of the Laser Additive Manufacturing process.
Jyoti Mazumder - One of the best experts on this subject based on the ideXlab platform.
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Melt-pool motion, temperature variation and dendritic morphology of Inconel 718 during pulsed- and continuous-wave Laser Additive Manufacturing: A comparative study
Materials and Design, 2017Co-Authors: Simeng Li, Keyang Liu, Wenjia Xiao, Yanqin Li, Xu Han, Jyoti Mazumder, Lijun SongAbstract:Pulsed-wave Laser Additive Manufacturing offers a number of advantages, such as a lower heat accumulation, a higher cooling rate, finer microstructures and improved mechanical properties over continuous-wave Laser Additive Manufacturing. However, how pulsed Laser acts on the melt pool motion, thermal field and hence microstructure is not clear. In this work, a three-dimensional transport model utilizing the level set method is developed to simulate the transient melt pool motion, heat/mass transfer and fluid flow for pulsed-wave Laser Additive Manufacturing. A boundary restriction on the fluid velocity along the liquid/gas interface is employed to confine the liquid flow within the melt pool. The simulated melt pool geometry and temperature are compared with experimental measurements. Moreover, melt pool geometry/motion, temperature variation, and their influence on the microstructure of fabricated samples using both pulsed- and continuous-wave Lasers are analyzed. It is found that pulsed-wave Laser Additive Manufacturing features a rounder shaped melt pool, a periodically heartbeat-like motion of the melt pool and a doubled cooling rate. The higher tilt angle of the solidification front results in a dendrite growth direction more tilted to the Laser scanning direction and the higher cooling rate results in finer columnar dendrites.
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Effects of Laser modes on Nb segregation and Laves phase formation during Laser Additive Manufacturing of nickel-based superalloy
Materials Letters, 2017Co-Authors: H. Xiao, L. M. Cha, S. M. Li, W.j. Xiao, Y Q Li, Jyoti Mazumder, L J SongAbstract:Nb-bearing nickel-based superalloys were fabricated by Laser Additive Manufacturing using both continuous-wave (CW) and quasi-continuous-wave (QCW) Laser modes. Effects of Laser modes on Nb segregation and Laves phase morphology were investigated. The responses to aging treatments of two different fabricated samples were also investigated. CW mode tends to develop columnar dendrites, relative severe Nb segregation and continuous distributed Laves phase, while QCW mode tends to produce fine equiaxed dendrites, less Nb segregations and fine discrete Laves phase. In addition, the QCW sample responses better to aging treatment than the CW sample.
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Laves phase control of Inconel 718 alloy using quasi-continuous-wave Laser Additive Manufacturing
Materials and Design, 2017Co-Authors: H. Xiao, Simeng Li, Xu Han, Jyoti Mazumder, Lijun SongAbstract:Nb segregation and Laves phase formation are known to be detrimental to mechanical properties of Inconel 718. However, effective efforts to suppress Nb segregation and Laves phase formation are still lacking. In this work, a quasi-continuous-wave (QCW) Laser Additive Manufacturing (LAM) is used to control Nb segregation and Laves phase formation. Thermal behaviors of the molten pool, microstructural evolution and mechanical response of the fabricated samples to aging treatment were investigated. Compared to continuous wave (CW) LAM, QCW-LAM results in a refined and equiaxed dendrite microstructure, a reduced Nb segregation, and attended fine and discrete Laves phase particles, due to an improved cooling rate with one order of magnitude and a decreased solidification time of the molten pool. In addition, the QCW sample shows a good response to aging treatment with a higher hardness and more desired tensile properties due to the reduced Nb segregation, the obtained fine discrete Laves phase and the refined dendrite microstructure. The tensile strength (~ 1404.1 MPa), the yield strength (~ 1120.6 MPa) and the ductility (~ 12.4 pct) of the aged QCW sample are higher than the ASTM limits of the wrought Inconel 718 alloy.
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Real-Time Composition Monitoring Using Support Vector Regression of Laser-Induced Plasma for Laser Additive Manufacturing
IEEE Transactions on Industrial Electronics, 2017Co-Authors: Lijun Song, Wenkang Huang, Jyoti MazumderAbstract:Laser Additive Manufacturing has gained widespread adoption in recent years. However, process diagnosis and process control lag behind the progresses of other key technologies, which make the product quality control a challenging problem. This work proposes an operating parameter conditioned support vector regression (SVR) method that uses processing parameter conditioned kernel function to achieve a processing parameter independent in-situ composition prediction. Two different features of Laser-induced plasma, spectral line-intensity-ratio, and both spectral line-intensity-ratio and spectral integrated intensity were used to train the SVR. Composition measurements using a calibration curve method, partial least square regression, and artificial neural networks are also performed for comparison. The results show that the SVR with both spectral line-intensity-ratio and spectral integrated intensity as inputs has the best performance due to linearly separable point clusters in the high-dimensional space. Laser power independent composition prediction is achieved and real-time composition predictions are validated. It is proved that the operating parameter conditioned SVR provides a more accurate, a more universal, and an operating parameter independent prediction. Moreover, operating parameter conditioned SVR provides a potential data-driven-based approach for real-time composition monitoring of the Laser Additive Manufacturing process.
Reinhart Poprawe - One of the best experts on this subject based on the ideXlab platform.
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Laser Additive Manufacturing of Zn porous scaffolds: Shielding gas flow, surface quality and densification
Journal of Materials Science and Technology, 2019Co-Authors: Peng Wen, Maximilian Voshage, Lucas Jauer, Yanzhe Chen, Reinhart Poprawe, Yu Qin, Johannes Henrich SchleifenbaumAbstract:Zn based metals have exhibited promising prospects as a structural material for biodegradable applications. Pure Zn porous scaffolds were produced by Laser powder bed fusion (LPBF) based on data files of designing and CT scanning. Massive Zn evaporation during Laser melting largely influenced the formation quality during LPBF of Zn metal. The metal vapor in processing chamber was blown off and suctioned out efficiently by an optimized gas circulation system. Numerical analysis was used to design and testify the performance of gas flow. The surface of scaffolds was covered with numerous particles in different sizes. Processing pores occurred near the outline contour of struts. The average grain size in width was 8.5 μm, and the hardness was 43.8 HV. Chemical plus electrochemical polishing obtained uniform and smooth surface without processing pores, but the diameter of struts reduced to 250 μm from the design value 300 μm. The poor surface quality and processing pores were resulted by the splashing particles included spatters and powders due to the recoil force of evaporation, and the horizontal movement of liquid metal due to overheating and wetting. The insufficient melting at the outline contour combined with good wetting of Zn liquid metal further increased the surface roughness and processing pores.
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Laser Additive Manufacturing of zn metal parts for biodegradable applications processing formation quality and mechanical properties
Materials & Design, 2018Co-Authors: Peng Wen, Maximilian Voshage, Lucas Jauer, Yanzhe Chen, Johannes Henrich Schleifenbaum, Reinhart Poprawe, Yu QinAbstract:Abstract Zn based metals have exhibited promising applications for biodegradable implants. Only a handful of very recent reports were found on Additive Manufacturing of Zn metal by selective Laser melting (SLM). This work provided a systematic study on densification, surface roughness and mechanical properties regarding SLM of Zn metal. Single track surface after Laser melting was rugged and twisted with a large amount of attached particles due to severe Zn evaporation. For SLM produced solid parts, the relative density was more than 99.50%; the surface roughness Sa was 9.15–10.79 μm for as-melted status and 4.83 μm after sandblasting, both comparable to optimal results obtained by SLM of common metals. The microstructure was made up of fine columnar grains. The average values of hardness, elastic modulus, yield strength, ultimate strength and elongation were 42 HV, 23GPa, 114 MPa, 134 MPa, and 10.1% respectively, better than those obtained by most Manufacturing methods. The superior mechanical properties were attributed to high densification and fine grains resulted by optimal processing control of Zn evaporation and Laser energy input. Cardiovascular stents were printed out to demonstrate Additive Manufacturing ability for complicated structures. All the results indicate the encouraging prospect of Additive Manufacturing of Zn based metals for biodegradable applications.
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Laser Additive Manufacturing of ultrafine TiC particle reinforced Inconel 625 based composite parts: Tailored microstructures and enhanced performance
Materials Science and Engineering: A, 2015Co-Authors: Chen Hong, Moritz Alkhayat, Wolf Urban, Sainan Cao, Pengpeng Yuan, D D Gu, Donghua Dai, Andres Gasser, Ingomar Kelbassa, Minlin Zhong, Andreas Weisheit, Dongdong Gu, Reinhart PopraweAbstract:Laser metal deposition (LMD) Additive Manufacturing process was applied to produce ultrafine TiC particle reinforced Inconel 625 composite parts. The effects of Laser energy input per unit length (LEIPUL) on microstructure development, densification response, and mechanical performance including wear performance and tensile properties were comprehensively studied. A relationship of processing conditions, microstructural characteristics, mechanical performance, and underlying strengthening mechanisms was proposed for a successful LMD of high-performance Inconel based composite parts. It revealed that using an insufficient LEIPUL of 33kJ/m lowered the densification behavior of LMD-processed parts, due to the appearance of residual large-sized pores in inter-layer areas of the parts. An increase in LEIPUL above 100kJ/m yielded the near fully dense composite parts after LMD. On increasing LEIPUL, the TiC reinforcing particles became significantly refined and smoothened via the elevated melting of particle surfaces and the dispersion state of ultra-fine reinforcing particles was homogenized due to the efficient action of Marangoni flow within the molten pool. The dendrites of Ni–Cr ? matrix underwent a successive change from an insufficiently developed, disordered microstructure to a refined, ordered microstructure with the increase of LEIPUL. However, the columnar dendrites of the matrix were coarsened apparently at an excessive LEIPUL of 160kJ/m because of the elevated thermalization of the input Laser energy. The formation of the refined columnar dendrites of Ni–Cr ? matrix combined with the homogeneously distributed ultra-fine reinforcing particles contributed to the enhancement of wear performance of LMD-processed composites with a considerably low coefficient of friction (COF) of 0.30 and reduced wear rate of 1.3×10?4mm3/Nm. The optimally prepared TiC/Inconel 625 composite parts demonstrated a ductile fracture mode with a sufficiently high tensile strength of 1077.3MPa, yield strength of 659.3MPa, and elongation of 20.7%. The superior tensile properties of LMD-processed parts were attributed to the significant grain refinement effect of the matrix during Laser processing and the efficient prohibition of ultrafine reinforcing particles on the mobility of dislocations.
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Laser Additive Manufacturing of metallic components materials processes and mechanisms
International Materials Reviews, 2012Co-Authors: Dongdong Gu, Wilhelm Meiners, Konrad Wissenbach, Reinhart PopraweAbstract:AbstractUnlike conventional materials removal methods, Additive Manufacturing (AM) is based on a novel materials incremental Manufacturing philosophy. Additive Manufacturing implies layer by layer shaping and consolidation of powder feedstock to arbitrary configurations, normally using a computer controlled Laser. The current development focus of AM is to produce complex shaped functional metallic components, including metals, alloys and metal matrix composites (MMCs), to meet demanding requirements from aerospace, defence, automotive and biomedical industries. Laser sintering (LS), Laser melting (LM) and Laser metal deposition (LMD) are presently regarded as the three most versatile AM processes. Laser based AM processes generally have a complex non-equilibrium physical and chemical metallurgical nature, which is material and process dependent. The influence of material characteristics and processing conditions on metallurgical mechanisms and resultant microstructural and mechanical properties of AM proc...
Xu Han - One of the best experts on this subject based on the ideXlab platform.
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phase congruency melt pool edge extraction for Laser Additive Manufacturing
Journal of Materials Processing Technology, 2017Co-Authors: Lijun Song, Fanghua Wang, Xu HanAbstract:Abstract Melt pool geometry, as one of the most important built attributes that reflect the stability of an Additive Manufacturing process, has been widely used for process monitoring and process control. Currently, intensity-based gray-level image processing is generally used to extract the melt pool boundaries. However, selection of proper threshold is challenging due to the intensity-related noise and disturbance from blurred areas, flares and speckles. This paper presents a phase congruency melt pool edge extraction approach that performs well for phase-invariant but intensity-variant image boundary extraction. The results show that the phase congruency edge extraction approach can not only robustly handle disturbances from blurred areas, flares, black areas and incandescent droplets, but also obtain more accurate melt pool geometries. A real-time melt pool monitoring system is developed to monitor a geometrically dependent and time varying melt pool evolution during an Additive Manufacturing process.
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Melt-pool motion, temperature variation and dendritic morphology of Inconel 718 during pulsed- and continuous-wave Laser Additive Manufacturing: A comparative study
Materials and Design, 2017Co-Authors: Simeng Li, Keyang Liu, Wenjia Xiao, Yanqin Li, Xu Han, Jyoti Mazumder, Lijun SongAbstract:Pulsed-wave Laser Additive Manufacturing offers a number of advantages, such as a lower heat accumulation, a higher cooling rate, finer microstructures and improved mechanical properties over continuous-wave Laser Additive Manufacturing. However, how pulsed Laser acts on the melt pool motion, thermal field and hence microstructure is not clear. In this work, a three-dimensional transport model utilizing the level set method is developed to simulate the transient melt pool motion, heat/mass transfer and fluid flow for pulsed-wave Laser Additive Manufacturing. A boundary restriction on the fluid velocity along the liquid/gas interface is employed to confine the liquid flow within the melt pool. The simulated melt pool geometry and temperature are compared with experimental measurements. Moreover, melt pool geometry/motion, temperature variation, and their influence on the microstructure of fabricated samples using both pulsed- and continuous-wave Lasers are analyzed. It is found that pulsed-wave Laser Additive Manufacturing features a rounder shaped melt pool, a periodically heartbeat-like motion of the melt pool and a doubled cooling rate. The higher tilt angle of the solidification front results in a dendrite growth direction more tilted to the Laser scanning direction and the higher cooling rate results in finer columnar dendrites.
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Laves phase control of Inconel 718 alloy using quasi-continuous-wave Laser Additive Manufacturing
Materials and Design, 2017Co-Authors: H. Xiao, Simeng Li, Xu Han, Jyoti Mazumder, Lijun SongAbstract:Nb segregation and Laves phase formation are known to be detrimental to mechanical properties of Inconel 718. However, effective efforts to suppress Nb segregation and Laves phase formation are still lacking. In this work, a quasi-continuous-wave (QCW) Laser Additive Manufacturing (LAM) is used to control Nb segregation and Laves phase formation. Thermal behaviors of the molten pool, microstructural evolution and mechanical response of the fabricated samples to aging treatment were investigated. Compared to continuous wave (CW) LAM, QCW-LAM results in a refined and equiaxed dendrite microstructure, a reduced Nb segregation, and attended fine and discrete Laves phase particles, due to an improved cooling rate with one order of magnitude and a decreased solidification time of the molten pool. In addition, the QCW sample shows a good response to aging treatment with a higher hardness and more desired tensile properties due to the reduced Nb segregation, the obtained fine discrete Laves phase and the refined dendrite microstructure. The tensile strength (~ 1404.1 MPa), the yield strength (~ 1120.6 MPa) and the ductility (~ 12.4 pct) of the aged QCW sample are higher than the ASTM limits of the wrought Inconel 718 alloy.
Johannes Henrich Schleifenbaum - One of the best experts on this subject based on the ideXlab platform.
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Laser Additive Manufacturing of copper chromium niobium alloys using gas atomized powder
International Journal of Materials Research, 2020Co-Authors: Dora Maischner, Andreas Weisheit, Johannes Henrich Schleifenbaum, Udo Fritsching, Anoop Kini, Volker Uhlenwinkel, Tim BiermannAbstract:Abstract Copper–chrome–niobium alloys exhibit excellent thermal and electrical properties combined with high strength at elevated temperatures. Additive Manufacturing techniques such as Laser metal...
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Laser Additive Manufacturing of biodegradable magnesium alloy WE43: A detailed microstructure analysis.
Acta Biomaterialia, 2019Co-Authors: Florian Bär, Lucas Jauer, Johannes Henrich Schleifenbaum, Leopold Berger, Güven Kurtuldu, Robin Schäublin, Jörg F. LöfflerAbstract:Abstract WE43, a magnesium alloy containing yttrium and neodymium as main alloying elements, has become a well-established bioresorbable implant material. Implants made of WE43 are often fabricated by powder extrusion and subsequent machining, but for more complex geometries Laser powder bed fusion (LPBF) appears to be a promising alternative. However, the extremely high cooling rates and subsequent heat treatment after solidification of the melt pool involved in this process induce a drastic change in microstructure, which governs mechanical properties and degradation behaviour in a way that is still unclear. In this study we investigated the changes in the microstructure of WE43 induced by LPBF in comparison to that of cast WE43. We did this mainly by electron microscopy imaging, and chemical mapping based on energy-dispersive X-ray spectroscopy in conjunction with electron diffraction for the identification of the various phases. We identified different types of microstructure: an equiaxed grain zone in the center of the Laser-induced melt pool, and a lamellar zone and a partially melted zone at its border. The lamellar zone presents dendritic lamellae lying on the Mg basal plane and separated by aligned Nd-rich nanometric intermetallic phases. They appear as globular particles made of Mg3Nd and as platelets made of Mg41Nd5 occurring on Mg prismatic planes. Yttrium is found in solid solution and in oxide particles stemming from the powder particles’ shell. Due to the heat influence on the lamellar zone during subsequent Laser passes, a strong texture developed in the bulk material after substantial grain growth. Statement of Significance Additively manufactured magnesium alloys have the potential of providing a major breakthrough in bone-reconstruction surgery by serving as biodegradable porous scaffold material. This study is the first to report in detail on the microstructure development of the established magnesium alloy WE43 fabricated by the Additive Manufacturing process of Laser Powder Bed Fusion (LPBF). It presents unique microstructural features which originate from the Laser-melting process. An in situ transmission electron microscopy heating experiment further demonstrates the development of two distinct intermetallic phases in Additively manufactured WE43 alloys. While one forms already during solidification, the other precipitates due to the ongoing heat treatment during LPBF processing.
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Laser Additive Manufacturing of Zn porous scaffolds: Shielding gas flow, surface quality and densification
Journal of Materials Science and Technology, 2019Co-Authors: Peng Wen, Maximilian Voshage, Lucas Jauer, Yanzhe Chen, Reinhart Poprawe, Yu Qin, Johannes Henrich SchleifenbaumAbstract:Zn based metals have exhibited promising prospects as a structural material for biodegradable applications. Pure Zn porous scaffolds were produced by Laser powder bed fusion (LPBF) based on data files of designing and CT scanning. Massive Zn evaporation during Laser melting largely influenced the formation quality during LPBF of Zn metal. The metal vapor in processing chamber was blown off and suctioned out efficiently by an optimized gas circulation system. Numerical analysis was used to design and testify the performance of gas flow. The surface of scaffolds was covered with numerous particles in different sizes. Processing pores occurred near the outline contour of struts. The average grain size in width was 8.5 μm, and the hardness was 43.8 HV. Chemical plus electrochemical polishing obtained uniform and smooth surface without processing pores, but the diameter of struts reduced to 250 μm from the design value 300 μm. The poor surface quality and processing pores were resulted by the splashing particles included spatters and powders due to the recoil force of evaporation, and the horizontal movement of liquid metal due to overheating and wetting. The insufficient melting at the outline contour combined with good wetting of Zn liquid metal further increased the surface roughness and processing pores.
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Laser Additive Manufacturing of zn metal parts for biodegradable applications processing formation quality and mechanical properties
Materials & Design, 2018Co-Authors: Peng Wen, Maximilian Voshage, Lucas Jauer, Yanzhe Chen, Johannes Henrich Schleifenbaum, Reinhart Poprawe, Yu QinAbstract:Abstract Zn based metals have exhibited promising applications for biodegradable implants. Only a handful of very recent reports were found on Additive Manufacturing of Zn metal by selective Laser melting (SLM). This work provided a systematic study on densification, surface roughness and mechanical properties regarding SLM of Zn metal. Single track surface after Laser melting was rugged and twisted with a large amount of attached particles due to severe Zn evaporation. For SLM produced solid parts, the relative density was more than 99.50%; the surface roughness Sa was 9.15–10.79 μm for as-melted status and 4.83 μm after sandblasting, both comparable to optimal results obtained by SLM of common metals. The microstructure was made up of fine columnar grains. The average values of hardness, elastic modulus, yield strength, ultimate strength and elongation were 42 HV, 23GPa, 114 MPa, 134 MPa, and 10.1% respectively, better than those obtained by most Manufacturing methods. The superior mechanical properties were attributed to high densification and fine grains resulted by optimal processing control of Zn evaporation and Laser energy input. Cardiovascular stents were printed out to demonstrate Additive Manufacturing ability for complicated structures. All the results indicate the encouraging prospect of Additive Manufacturing of Zn based metals for biodegradable applications.
