Additive manufacturing of stellite 6 superalloy by direct laser metal deposition – Part 2: Effects of scanning pattern and laser power reduction in differrent layers

Moradi, Mahmoud; Hasani, Arman; Beiranvand, Zeinab Malekshahi; Ashoori, A.

doi:10.1016/j.optlastec.2020.106455

Cited by 35 publications

(19 citation statements)

References 33 publications

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“…It is expected that the catchment factor increases by increasing the powder feed rate, but the powder feed rate has a turning point. It means that the powder feed rate increases to a certain extent, but suddenly it makes a situation for absorbing more powder, and in this stage, the amount of catchment declines [50].…”

Section: Catchmentmentioning

confidence: 99%

Direct Laser Metal Deposition (DLMD) Additive Manufacturing (AM)of Inconel 718 Superalloy: Elemental, Microstructural and Physical Properties Evaluation

Moradi

Pourmand

Hasani

et al. 2021

Preprint

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In this study direct laser metal deposition (DLMD) technique is adopted for the additive manufacturing (AM) of Inconel 718 Superalloy. To conduct the experiments, a 1 kW fiber laser with a coaxial nozzle head is used. The effects of scanning speed (for two values of 2.5 and 5 mm/s) as well as powder feed rate (for two values of 17.94 and 28.52 g/min) on the process were investigated. Characteristics of the 3D printed wall specimens such as the geometrical dimensions (width and height), microstructure observations, and the microhardness were obtained. In order to study the stability of the 3D manufactured walls, the height stability was considered for the investigation. Optical microscopy (OM), field emission electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), and mapping analysis were performed to derive the microstructural features of the additive manufactured samples. The Vickers microhardness test is used to evaluate the hardness distributions of additively manufactured parts. Catchment concept of the powder in DLMD process is used for explaining different trends of the process. Results indicated that, by decreasing the scanning speed, the width and height of the deposited layer increase. The average width of the additively manufactured samples directly depends on the scanning speed and the powder feed rate. Scanning speed has a reverse effect on the height stability; that is, the lower the scanning speed, the larger the stability. Microstructural results showed that because of the solidification process, the alloying elements will be accumulated in the grain boundaries. The non-uniform cooling rate and non-steady solidification rates of molten area in additive manufacturing process, the microhardness values of the additively manufactured samples following a fluctuated trend.

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Section: Catchmentmentioning

confidence: 99%

Direct Laser Metal Deposition (DLMD) Additive Manufacturing (AM)of Inconel 718 Superalloy: Elemental, Microstructural and Physical Properties Evaluation

Moradi

Pourmand

Hasani

et al. 2021

Preprint

Self Cite

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“…Due to its large primary carbides such as M7C3 and M23C6 that are dispersed in the Co-Cr matrix, this type of Stellite is harder and more wear-resistant [ 8 , 10 ]. Hence, they are used as coatings for high-temperature applications with severe abrasion and gouging [ 11 , 12 ]. Therefore, the excellent combination of wear and corrosion resistance at high temperatures has made hypereutectic Stellite 6 a proper candidate for the surface hardening of 17-4 PH [ 13 , 14 , 15 ].…”

Section: Introductionmentioning

confidence: 99%

“…There are various effective processing parameters in the LMD process (such as laser power and scanning speed) that must be considered to achieve a favorable cohesion and metallurgical bonding between the deposited layer and BM [15,[23][24][25]. Moradi et al [11] indicated that the lower grain size, lower distortion, higher microhardness, and higher stability can be achieved by employing a unidirectional scanning pattern in direct laser metal deposition of Stellite 6 powders on DIN 1.2714 hot work tool steel. In addition, Mazzucato et al [24] studied the effect of the process parameters on the shape and properties of the laser metal deposited (LMDed) 316 L. It was concluded that the powder feed rate can preclude a suitable bonding formation when low laser energies are used.…”

Section: Introductionmentioning

confidence: 99%

Effect of Laser Metal Deposition Parameters on the Characteristics of Stellite 6 Deposited Layers on Precipitation-Hardened Stainless Steel

et al. 2021

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Laser metal deposition (LMD) is one of the manufacturing processes in the industries, which is used to enhance the properties of components besides producing and repairing important engineering components. In this study, Stellite 6 was deposited on precipitation-hardened martensitic stainless steel (17-4 PH) by using the LMD process, which employed a pulsed Nd:YAG laser. To realize a favor deposited sample, the effects of three LMD parameters (focal length, scanning speed, and frequency) were investigated, as well as microstructure studies and the results of a microhardness test. Some cracks were observed in the deposited layers with a low scanning speed, which were eliminated by an augment of the scanning speed. Furthermore, some defects were found in the deposited layers with a high scanning speed and a low frequency, which can be related to the insufficient laser energy density and a low overlapping factor. Moreover, various morphologies were observed within the microstructure of the samples, which can be attributed to the differences in the stability criterion and cooling rate across the layer. In the long run, a defect-free sample (S-120-5.5-25) possessing suitable geometrical attributes (wetting angle of 57° and dilution of 25.1%) and a better microhardness property at the surface (≈335 Hv) has been introduced as a desirable LMDed sample.

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“…In addition to RS, the scanning pattern also affects the microstructure and other properties, as reported by Moradi et al (2020) and Wan et al (2018). However, few studies discuss the effects of the scanning pattern on performance and the accurate assessment of its comprehensive impact.…”

Section: Introductionmentioning

confidence: 99%

Effects of different scanning patterns on nickel alloy-directed energy deposition based on thermal analysis

Zhang

Jing

et al. 2021

Virtual and Physical Prototyping

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A novel and comprehensive evaluation index considering various processing parameters in additive manufacturing with four different scanning patterns was proposed. The relationship between the evaluation index and the performance of parts made by directed energy deposition was established and verified by experiments. The differences of thermal evolution between four scanning patterns were analysed. Comprehensive evaluation indices corresponding to different scanning patterns were calculated by integrating the contributions of various parameters, such as delamination, warping, porosity, heat accumulation, cooling rate, dendrite spacing, and deposition efficiency. The comprehensive evaluation indices off our scanning patterns were ranked in the following order (from lowest to highest): single-track zigzag, single-track, bidirection, and spiral inward patterns. The performance of the single-track zigzag pattern was the best, and that of the spiral inward pattern was the worst. The single-track and bi-direction patterns showed intermediate performances under the same conditions. The closer the index is to zero, the better the performance. This index can be used for the quantitative evaluation of process quality and prediction of performance. It provides guidance for additive manufacturing process development and optimisation, reduces workload, and provides a new idea for quantitative performance evaluation and prediction of parts fabricated by additive manufacturing.

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Additive manufacturing of stellite 6 superalloy by direct laser metal deposition – Part 2: Effects of scanning pattern and laser power reduction in differrent layers

Cited by 35 publications

References 33 publications

Direct Laser Metal Deposition (DLMD) Additive Manufacturing (AM)of Inconel 718 Superalloy: Elemental, Microstructural and Physical Properties Evaluation

Direct Laser Metal Deposition (DLMD) Additive Manufacturing (AM)of Inconel 718 Superalloy: Elemental, Microstructural and Physical Properties Evaluation

Effect of Laser Metal Deposition Parameters on the Characteristics of Stellite 6 Deposited Layers on Precipitation-Hardened Stainless Steel

Effects of different scanning patterns on nickel alloy-directed energy deposition based on thermal analysis

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