Effect of Scanning Strategy in the L-PBF Process of 18Ni300 Maraging Steel

Rivalta, Francesco; Ceschini, Lorella; Jarfors, Anders E. W.; Stolt, Roland

doi:10.3390/met11050826

Cited by 13 publications

(11 citation statements)

References 54 publications

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“…The total strain energy density was fairly stable over the life cycle, regardless of the strain amplitude. Rivalta et al [ 11 ] studied the effects of scanning strategy on size, roughness, density, and hardness, indicating a significantly weaker influence of scanning strategy compared to residual stress and deformation. Unavoidable defects in the formation process, such as holes, cracks, splashes, and spheroidization, as well as the control of the forming structure, are important factors restricting the development of SLM technology [ 2 , 12 ].…”

Section: Introductionmentioning

confidence: 99%

Optimization of Process Parameters and Analysis of Microstructure and Properties of 18Ni300 by Selective Laser Melting

Gao

Zhao

et al. 2022

Materials

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In this research, we studied the influence of process parameters on the quality of selective laser melting of 18Ni300 maraging steel. The effects of laser power and scanning speed on the relative density and hardness of 18Ni300 were studied by single-factor experiment and the orthogonal experimental method. The relative optimal process parameters of 18Ni300 were obtained when the layer thickness was 0.03 mm, and the hatch space was 0.1 mm. The microstructures and mechanical properties of the samples formed under different process parameters were characterized. The results showed that the optimal hardness and relative density of the sample were 44.7 HRC and 99.98% when the laser power was 230 W and the scanning speed was 1100 mm/s, respectively; the microstructure of the material was uniform and dense, exhibiting few pores. Some columnar crystals appeared along the boundary of the molten pool due to vertical epitaxial growth. The orientation of fine grains at the boundary of the molten pool was random, and some coarse columnar crystals in the molten pool exhibited a certain orientational preference along the <001> orientation. In the case of optimal process parameters, the SLM-formed 18Ni300 was composed of 99.5% martensite and 0.5% retained austenite; the indentation hardness was distributed in the range of 3.2–5 GPa. The indentation modulus was between 142.8–223.4 GPa, exhibiting stronger fluctuations than the indentation hardness. The sample’s mechanical properties showed obvious anisotropy, while the tensile fracture characteristics exhibited necking. The tensile fracture morphology was ductile, and large equiaxed dimples and holes could be observed in the fiber area, accompanied by tearing characteristics.

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Section: Introductionmentioning

confidence: 99%

Optimization of Process Parameters and Analysis of Microstructure and Properties of 18Ni300 by Selective Laser Melting

Gao

Zhao

et al. 2022

Materials

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“…However, most of the materials that have been investigated were non-iron based, as their manufacturing was often combined with high production and material costs, or stainless or maraging steel [ 1 , 2 , 3 , 4 ]. Interest in the use of AM for cost-driven industries, tool steel applications in particular, has been increasing recently, which is reflected in the number of publications in the last years [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ].…”

Section: Introductionmentioning

confidence: 99%

PBF-EB of Fe-Cr-V Alloy for Wear Applications

Franke-Jurisch

Mirz

Wenz³

et al. 2022

Materials

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Due to the small variety of materials, the areas of application of additive manufacturing in the toolmaking industry are currently still limited. In order to overcome these material restrictions, AM material development for high carbon-containing iron-based materials, which are characterized by high strength, hardness, and wear resistance, must be intensified. However, these materials are often susceptible to crack formation or lack of fusion defects during processing. Therefore, these materials are preferentially suited for electron beam powder bed fusion (PBF-EB). In this paper, an Fe-Cr-V alloy with 10% vanadium is presented. Investigations were carried out on the PBF-EB system Arcam A2X. Specimens and demonstrators are characterized by a three-phase microstructure with an Fe-rich matrix and VC and M7C3 reinforcements. The resulting microstructures were characterized by scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). Furthermore, mechanical and physical properties were measured. A final field test was conducted to evaluate durability in use.

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“…In addition, laser scan strategy affects the thermal gradient, ultimately the microstructure and mechanical properties of SLM-built parts. Scanning strategy plays a remarkable role in the formation of defects such as balling effect or high residual stress [25]. Proper selection of scanning strategy increases the uniformity of temperature distribution and improves the properties of the 3D printed product [25], [26].…”

Section: Introductionmentioning

confidence: 99%

“…Scanning strategy plays a remarkable role in the formation of defects such as balling effect or high residual stress [25]. Proper selection of scanning strategy increases the uniformity of temperature distribution and improves the properties of the 3D printed product [25], [26]. Inappropriate laser parameters degrade the quality of parts by forming pores, causing cracks, or rougher surface.…”

Section: Introductionmentioning

confidence: 99%

In-Situ Monitoring and Defect Detection of Selective Laser Melting Process and Impact of Process Parameters on the Quality of Fabricated SS 316L

et al. 2022

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Selective Laser Melting (SLM) is an advanced Additive Manufacturing (AM) technique for the 3D printing of metals. SLM process parameters and different types of defects that may appear during the manufacturing process affect the quality of the final product. Setting laser parameters and online defect detection contributes to improving the quality of parts fabricated through SLM technology. In this study, the effect of the process parameters on the properties of the product built by the SLM process was investigated, and an in-situ monitoring platform was developed to detect two types of defects during the SLM process. Different samples were built from stainless steel AISI 316 L powder, utilizing various laser process parameters. Using microscopy imaging technique, the melt structure features of the constructed samples were tested, and the results were analyzed. The dependency of porosity formation on laser process parameters and scan strategy was investigated. Moreover, hardness test was performed for all built samples. The platform developed for in-situ monitoring purposes includes an AM machine equipped with pulsed laser, camera, illumination system, and powerful industrial computer equipped with Cameral Link Adapter, FPGA, and Real-Time (RT) modules. An algorithm was designed using LabVIEW R software based on Particle Analysis (PA) to cease the process in the event of detection of defect in any fused layers. The first defect was caused by changing the laser spot diameter, which altered the energy intensity of the laser on the surface, and the second defect was created by the uneven thickness of powder on the platform. The monitoring system detected both defects and stopped the process immediately according to the designed algorithm. Images were taken from the melting process layer by layer using a high-performance camera.INDEX TERMS Additive manufacturing (AM), focal point position, in-situ monitoring, laser beam diameter, laser energy density, particle analysis (PA), powder thickness, selective laser melting (SLM).

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Effect of Scanning Strategy in the L-PBF Process of 18Ni300 Maraging Steel

Cited by 13 publications

References 54 publications

Optimization of Process Parameters and Analysis of Microstructure and Properties of 18Ni300 by Selective Laser Melting

Optimization of Process Parameters and Analysis of Microstructure and Properties of 18Ni300 by Selective Laser Melting

PBF-EB of Fe-Cr-V Alloy for Wear Applications

In-Situ Monitoring and Defect Detection of Selective Laser Melting Process and Impact of Process Parameters on the Quality of Fabricated SS 316L

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