A review and a statistical analysis of porosity in metals additively manufactured by laser powder bed fusion

Wang, Dawei; Han, Hongjun; Sa, Bo; Li, Kelin; Yan, Jujie; Zhang, Jiazhen; Liu, Jianguang; He, Zhengdi; Wang, Ning; Yan, Ming

doi:10.29026/oea.2022.210058

Cited by 18 publications

(6 citation statements)

References 263 publications

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“…A combined approach of using mechanistic modeling and analysis of experimental data was implemented to derive and use a gas porosity index for predicting and controlling gas porosity during LPBF of common alloys. The pictures inside the "Experimental data" box are adapted from [7,61,62]. Figures taken from open-access articles [7,61] are under the terms and conditions of the Creative Commons Attribution (CC BY) license.…”

Section: Figurementioning

confidence: 99%

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Mitigation of Gas Porosity in Additive Manufacturing Using Experimental Data Analysis and Mechanistic Modeling

Sinha,

Mukherjee

2024

Materials

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Shielding gas, metal vapors, and gases trapped inside powders during atomization can result in gas porosity, which is known to degrade the fatigue strength and tensile properties of components made by laser powder bed fusion additive manufacturing. Post-processing and trial-and-error adjustment of processing conditions to reduce porosity are time-consuming and expensive. Here, we combined mechanistic modeling and experimental data analysis and proposed an easy-to-use, verifiable, dimensionless gas porosity index to mitigate pore formation. The results from the mechanistic model were rigorously tested against independent experimental data. It was found that the index can accurately predict the occurrence of porosity for commonly used alloys, including stainless steel 316, Ti-6Al-4V, Inconel 718, and AlSi10Mg, with an accuracy of 92%. In addition, experimental data showed that the amount of pores increased at a higher value of the index. Among the four alloys, AlSi10Mg was found to be the most susceptible to gas porosity, for which the value of the gas porosity index can be 5 to 10 times higher than those for the other alloys. Based on the results, a gas porosity map was constructed that can be used in practice for selecting appropriate sets of process variables to mitigate gas porosity without the need for empirical testing.

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Section: Figurementioning

confidence: 99%

“…The pictures inside the "Experimental data" box are adapted from [7,61,62]. Figures taken from open-access articles [7,61] are under the terms and conditions of the Creative Commons Attribution (CC BY) license. The figure taken from [62] is under the permission obtained from Elsevier.…”

Section: Figurementioning

confidence: 99%

Mitigation of Gas Porosity in Additive Manufacturing Using Experimental Data Analysis and Mechanistic Modeling

Sinha,

Mukherjee

2024

Materials

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“…It can be challenging to ensure that the metal particles are evenly dispersed, avoiding the particles clumping together or settling in specific areas; it can result in inconsistent production and reduced mechanical properties of the final product. FFF is susceptible to various production quality issues, including an anisotropic feature that reduces the mechanical strength of the part in specific directions (mainly in the Z-axis), warping, delamination, and poor surface finish [2,3,9,12,70,104,105]. Metal parts produced using FFF may have rough or uneven surfaces, affecting their functionality or aesthetics.…”

Section: Challenges To Overcome From Using Fff With Metallic Materialsmentioning

confidence: 99%

Fused Filament Fabrication for Metallic Materials: A Brief Review

Costa,

Sequeiros,

Vieira

2023

Materials

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Fused filament fabrication (FFF) is an extrusion-based additive manufacturing (AM) technology mostly used to produce thermoplastic parts. However, producing metallic or ceramic parts by FFF is also a sintered-based AM process. FFF for metallic parts can be divided into five steps: (1) raw material selection and feedstock mixture (including palletization), (2) filament production (extrusion), (3) production of AM components using the filament extrusion process, (4) debinding, and (5) sintering. These steps are interrelated, where the parameters interact with the others and have a key role in the integrity and quality of the final metallic parts. FFF can produce high-accuracy and complex metallic parts, potentially revolutionizing the manufacturing industry and taking AM components to a new level. In the FFF technology for metallic materials, material compatibility, production quality, and cost-effectiveness are the challenges to overcome to make it more competitive compared to other AM technologies, like the laser processes. This review provides a comprehensive overview of the recent developments in FFF for metallic materials, including the metals and binders used, the challenges faced, potential applications, and the impact of FFF on the manufacturing (prototyping and end parts), design freedom, customization, sustainability, supply chain, among others.

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“…Typical flaws include porosities, incomplete fusion holes, delamination, and cracks [11]. Pores negatively affect the performance of additively manufactured components [12][13][14]. According to Al-Maharma et al [15], surface porosity affects corrosion resistance, subsurface porosity fatigue strength, spherical porosity stiffness, and irregular porosity mechanical strength.…”

Section: Introductionmentioning

confidence: 99%

Influence of the Processing Parameters on the Microstructure and Mechanical Properties of 316L Stainless Steel Fabricated by Laser Powder Bed Fusion

Barrionuevo,

Ramos-Grez,

Sánchez-Sánchez

et al. 2024

JMMP

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Complex thermo-kinetic interactions during metal additive manufacturing reduce the homogeneity of the microstructure of the produced samples. Understanding the effect of processing parameters over the resulting mechanical properties is essential for adopting and popularizing this technology. The present work is focused on the effect of laser power, scanning speed, and hatch spacing on the relative density, microhardness, and microstructure of 316L stainless steel processed by laser powder bed fusion. Several characterization techniques were used to study the microstructure and mechanical properties: optical, electron microscopies, and spectrometry. A full-factorial design of experiments was employed for relative density and microhardness evaluation. The results derived from the experimental work were subjected to statistical analysis, including the use of analysis of variance (ANOVA) to determine both the main effects and the interaction between the processing parameters, as well as to observe the contribution of each factor on the mechanical properties. The results show that the scanning speed is the most statistically significant parameter influencing densification and microhardness. Ensuring the amount of volumetric energy density (125 J/mm3) used to melt the powder bed is paramount; maximum densification (99.7%) is achieved with high laser power and low scanning speed, while hatch spacing is not statistically significant.

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A review and a statistical analysis of porosity in metals additively manufactured by laser powder bed fusion

Cited by 18 publications

References 263 publications

Mitigation of Gas Porosity in Additive Manufacturing Using Experimental Data Analysis and Mechanistic Modeling

Mitigation of Gas Porosity in Additive Manufacturing Using Experimental Data Analysis and Mechanistic Modeling

Fused Filament Fabrication for Metallic Materials: A Brief Review

Influence of the Processing Parameters on the Microstructure and Mechanical Properties of 316L Stainless Steel Fabricated by Laser Powder Bed Fusion

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