Characterization of 17-4PH alloy processed by selective laser melting

Ponnusamy, P.; Masood, Syed H.; Palanisamy, Suresh; Rashid, Rizwan Abdul Rahman; Ruan, Dong

doi:10.1016/j.matpr.2017.07.196

Cited by 18 publications

(8 citation statements)

References 8 publications

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“…The results show that laser power at 270 W, vertical orientation, layer thickness of 30 µm and defocus distance of -6 mm exhibit an improved mechanical performance [153,154]. Study on microstructural analysis of 17-4PH stainless steel under various heat treatments, atom-probe field ion microscopy (APFIM) and transmission electron microscopy (TEM) show that hardness and yield strength increase after aging at 400 °C, over a prolonged aging (400 °C at 5000 h) [155]. Using two different atomizing media (nitrogen and water) and two different SLM post-processing (solutionizing at 1050 °C and 315 °C, aging at 482 °C for each temperature), mechanical properties and microstructural characterization are analyzed.…”

Section: Laser Powder Bed Fusion Additive Manufacturingmentioning

confidence: 98%

Conventional and Additively Manufactured Stainless Steels: A Review

Michla

Rajini

Krishnasamy

et al. 2021

Trans Indian Inst Met

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For the last three decades, enormous manufacturing processes have been widely employed in the field of transportation (aviation, automobile and marine) as well as various industrial sectors. Among the invented techniques, conventional manufacturing plays a versatile and cost effective role, but additive manufacturing (AM) possesses a more significant advantage of handling complicated parts or complex geometrical structures. The conventional processes were used from ancient times until the development of other advanced techniques. In recent development of technology, AM technology has shown a tremendous change in the manufacturing field. The process of development in AM began with polymers, then to composites and advanced to nanocomposites, continuously. AM provides a waste-free production management system with enhanced processes. Therefore, this detailed and compendious review describes the different stainless steels fabricated through conventional and AM techniques. It is evident that AM proves better than other several conventional techniques, by three dimensional (3D) printing of quality and complex stainless steels components that are impossible to manufacture through other methods. Notwithstanding, there still need of much efforts to improve AM technique by reducing the manufacturing cost, supporting mass production and printing large stainless steel components.With an increase in invention of various efficient state-of-the-art engineering software, robots in manufacturing, artificial intelligence and smart manufacturing, the aforementioned drawbacks of AM technique/3D printing of various stainless steel structures will be soon eradicated.

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Section: Laser Powder Bed Fusion Additive Manufacturingmentioning

confidence: 98%

Conventional and Additively Manufactured Stainless Steels: A Review

Michla

Rajini

Krishnasamy

et al. 2021

Trans Indian Inst Met

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“…Ponnusamy [135] investigated the effect of defocus distance of the laser beam on the surface characteristics of 17-4 PH stainless-steel parts manufactured by L-PBF. The results showed that the maximum microhardness was about 414 HV with minimal surface roughness for samples with a defocus of -4 mm at 85% laser power (maximum power 300 W).…”

Section: Effect Of Process Parameters On Hardnessmentioning

confidence: 99%

Laser Powder Bed Fusion of Precipitation-Hardened Martensitic Stainless Steels: A Review

Zai

Zhang

Wang

et al. 2020

Metals

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Martensitic stainless steels are widely used in industries due to their high strength and good corrosion resistance performance. Precipitation-hardened (PH) martensitic stainless steels feature very high strength compared with other stainless steels, around 3-4 times the strength of austenitic stainless steels such as 304 and 316. However, the poor workability due to the high strength and hardness induced by precipitation hardening limits the extensive utilization of PH stainless steels as structural components of complex shapes. Laser powder bed fusion (L-PBF) is an attractive additive manufacturing technology, which not only exhibits the advantages of producing complex and precise parts with a short lead time, but also avoids or reduces the subsequent machining process. In this review, the microstructures of martensitic stainless steels in the as-built state, as well as the effects of process parameters, building atmosphere, and heat treatments on the microstructures, are reviewed. Then, the characteristics of defects in the as-built state and the causes are specifically analyzed. Afterward, the effect of process parameters and heat treatment conditions on mechanical properties are summarized and reviewed. Finally, the remaining issues and suggestions on future research on L-PBF of martensitic precipitation-hardened stainless steels are put forward.Metals 2020, 10, 255 2 of 25 types of microstructures can be obtained with different heat treatment processes [9]. The typical temperature range for aging heat treatment for this alloy is 480-620 • C [1]. Under the H900 condition (aging temperature: 482 • C, time: 1 h), the precipitation in 17-4 PH stainless steel begins with Cu-rich precipitates (bcc, body center cubic) that maintain a coherent relationship with the matrix, which would lead to an increase in tensile strength and toughness [4]. These precipitates can transform into non-coherent Cu-rich particles (fcc, face center cubic) after extended aging at 400 • C [5]. After experiencing over-aging, the precipitates are coarsened. The number of precipitates is reduced, and the coherence relationship is also destroyed [6,10]. These changes together lead to a decrease in mechanical strength, but an increase in ductility and impact toughness.PH stainless steels are widely used in the aerospace industry [11,12], the marine industry [13], nuclear reactor components [14], chemical process equipment [15], and medical apparatus due to their high tensile strength, impact strength, fracture toughness, and corrosion resistance at typical service temperatures below 300 • C [15,16]. Most of these parts are important load-bearing components of heavy machinery in a demanding service environment. However, PH stainless steels have poor workability and machinability due to their high strength and high hardness, which result in a long production cycle and difficulties in obtaining desired shapes through conventional machining and forming processes [17].Due to the high strength and high hardness of PH steels, they are difficult to b...

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“…In the SLM study done by Metelkova et al [23], the variation of the width with defocusing is less evident. Ponnusamy et al [25] evaluated the influence of the laser defocus distance on the surface properties, microstructure, and hardness of the SLM parts, when applying a high constant input energy. This research shows increasing hardening with a negative defocus.…”

Section: Introductionmentioning

confidence: 99%

Laser Defocusing Effect on the Microstructure and Defects of 17-4PH Parts Additively Manufactured by SLM at a Low Energy Input

Leo

Cabibbo

Prete

et al. 2021

Metals

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In this paper, the microstructure, defects, hardness, and tensile strength of the 17-4PH specimens manufactured additively using the selective laser melting (SLM) technique were studied. The analyzed parts (10 mm size cubic specimens and tensile specimens) were manufactured with different defocus parameter values (−1, 0, +1 mm) in order to evaluate this effect with a low power laser (38 W). The study was carried out on three different sections of each cubic specimen, one perpendicular to the laser beam or SLM manufacturing direction (transversal section), and another two parallel to the laser beam direction (longitudinal sections). The specimens microstructures were analyzed with an X-ray diffraction technique, as well as optical, scanning electron, and transmission electron microscopes. Image J software was used to characterize the defects and phase ratio. In addition, hardness and tensile tests were performed according to the corresponding standards. The results show that the amount of austenitic phase and the average grain size varied with defocusing. The percentage of defective area was less than 0.25%. The analyzed defocus distance did not affect the number and average size of the defects. Adjusting the defocusing SLM parameter is important for manufacturing parts with good mechanical properties.

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Characterization of 17-4PH alloy processed by selective laser melting

Cited by 18 publications

References 8 publications

Conventional and Additively Manufactured Stainless Steels: A Review

Conventional and Additively Manufactured Stainless Steels: A Review

Laser Powder Bed Fusion of Precipitation-Hardened Martensitic Stainless Steels: A Review

Laser Defocusing Effect on the Microstructure and Defects of 17-4PH Parts Additively Manufactured by SLM at a Low Energy Input

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