Effects of particle characteristics on the microstructure and mechanical properties of 17-4 PH stainless steel fabricated by laser-powder bed fusion

Irrinki, Harish; Jangam, John Samuel Dilip; Pasebani, Somayeh; Badwe, Sunil; Stitzel, Jason; Kate, Kunal H.; Gülsoy, H. Özkan; Atre, Sundar V.

doi:10.1016/j.powtec.2018.03.025

Cited by 77 publications

(34 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[1][2][3][4][5][6][7][8][9][10] In general, the above processing conditions along with powder characteristics such as size, shape, and purity significantly determine the density, microstructures, and properties obtained from L-PBF parts. [6][7][8][11][12][13][14][15][16][17] In our former work, 18,19 a comprehensive study was performed to understand the role powder characteristics such as powder type, shape, and size along with L-PBF processing conditions on densification, mechanical properties, and microstructure of 17-4 PH stainless steel L-PBF parts. It was found that the % theoretical density, ultimate tensile strength, and hardness of L-PBF parts are sensitive to L-PBF processing conditions and starting powder shape, size, and type.…”

Section: Introductionmentioning

confidence: 99%

Microstructures, properties, and applications of laser sintered 17‐4PH stainless steel

Irrinki

Nath

Alhofors³

et al. 2019

J Am Ceram Soc

Self Cite

View full text Add to dashboard Cite

The effects of hot isostatic pressing (HIP) on the densification, mechanical properties, and microstructures of laser‐powder bed fusion (L‐PBF) 17‐4 PH stainless steel parts were studied using gas‐ and water‐atomized powders. The % theoretical density, ultimate tensile strength, yield strength, elongation, and hardness of as‐printed and HIP‐ed L‐PBF parts were sensitive to energy density and starting powder shape, size, and type. At low‐energy densities of 64 and 80 J/mm3, densification was significant for water‐atomized L‐PBF parts when subjected to HIP treatment and density increased from 90% to 97%. For all the energy densities, the gas‐atomized L‐PBF parts after the HIP treatment showed significantly higher tensile strength, yield strength, and hardness when compared to water‐atomized L‐PBF parts properties. At low‐energy densities of 64 and 80 J/mm3, long columnar grains in the as‐printed L‐PBF parts did not change significantly after the HIP treatment whereas the columnar grains present in as‐printed gas‐atomized L‐PBF parts completely disappeared when subjected to HIP treatment. However, at high‐energy densities of 84 and 104 J/mm3, the columnar grains in as‐printed L‐PBF gas‐ and water‐atomized L‐PBF parts were changed to equiaxed grains and showed a higher level of homogenization when subjected to HIP treatment. This variation in grains and grain size had significantly affected the yield strength and elongation of HIP‐treated gas‐ and water‐atomized L‐PBF parts.

show abstract

Section: Introductionmentioning

confidence: 99%

Microstructures, properties, and applications of laser sintered 17‐4PH stainless steel

Irrinki

Nath

Alhofors³

et al. 2019

J Am Ceram Soc

Self Cite

View full text Add to dashboard Cite

show abstract

“…The effects of powder types associated with manufacturing atmosphere on the final microstructure of L-PBF 17-4 PH steels are listed in the Table 1. [125]. (reproduced from [125], with permission from Elsevier, 2018).…”

Section: Microstructure In As L-pbfed Statementioning

confidence: 99%

“…Factors including powder surface, particle shape, particle size, and flowability of the powder can affect the bulk density of powder [130]. Density of the L-PBF parts is often measured using a method based on Archimedes' law [115,125,129]. Hu [131] demonstrated that scan speed and slice thickness have a significant impact on the L-PBF part's density.…”

Section: Defectsmentioning

confidence: 99%

“…However, in horizontal samples, these layers are parallel to the loading axis, which hinders the opening and expansion of the voids [26]. The increase in strength could be attributed to the relatively higher density of the manufactured part at a higher laser energy density, which produces sufficient heat to melt the powder, and the fraction of martensitic phase increased in the part made in water-atomized powder [93,125]. Furthermore, the strength of the as-built sample after heat treatment was improved to different extents both shown in Table 8.…”

Section: Tensile Propertiesmentioning

confidence: 99%

See 1 more Smart Citation

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

Zai

Zhang

Wang

et al. 2020

Metals

View full text Add to dashboard Cite

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...

show abstract

“…Mechanical and corrosion properties in previous research studies performed by our group showed that 17-4 PH stainless can be used as a starting material for the fabrication of injection mold tools [39]. The detailed information about the powder characterization can be found in our previous papers [39][40][41][42].…”

Section: Methodsmentioning

confidence: 99%

Tooling for injection molding using laser-powder bed fusion.

Buxani¹

View full text Add to dashboard Cite

Effects of particle characteristics on the microstructure and mechanical properties of 17-4 PH stainless steel fabricated by laser-powder bed fusion

Cited by 77 publications

References 26 publications

Microstructures, properties, and applications of laser sintered 17‐4PH stainless steel

Microstructures, properties, and applications of laser sintered 17‐4PH stainless steel

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

Tooling for injection molding using laser-powder bed fusion.

Contact Info

Product

Resources

About