Effect of Hot Isostatic Pressing and Powder Feedstock on Porosity, Microstructure, and Mechanical Properties of Selective Laser Melted AlSi10Mg

doi:10.1007/s13632-018-0456-z

Title: Effect of Hot Isostatic Pressing and Powder Feedstock on Porosity, Microstructure, and Mechanical Properties of Selective Laser Melted AlSi10Mg

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Abstract

AlSi10Mg tensile bars were additively manufactured using the powder-bed selective laser melting process. Samples were subjected to stress relief annealing and hot isostatic pressing. Tensile samples built using fresh, stored, and reused powder feedstock were characterized for microstructure, porosity, and mechanical properties. Fresh powder exhibited the best mechanical properties and lowest porosity while stored and reused powder exhibited inferior mechanical properties and higher porosity. The microstructure of stress relieved samples was fine and exhibited (001) texture in the z-build direction. Microstructure for hot isostatic pressed samples was coarsened with fainter (001) texture. To investigate surface and interior defects, scanning electron microscopy, optical fractography, and laser scanning microscopy techniques were employed. Hot isostatic pressing eliminated internal pores and reduced the size of surface porosity associated with the selective laser melting process. Hot isostatic pressing tended to increase ductility at the expense of decreasing strength. Furthermore, scatter in ductility of hot isostatic pressed parts suggests that the presence of unclosed surface porosity facilitated fracture with crack propagation inward from the surface of the part.

Authors:

Finfrock, Christopher B. ^[1]; Exil, Andrea ^[1]; Carroll, Jay D. ^[1]; Deibler, Lisa Anne ^[1]

Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

Publication Date:: 2018-06-06

Research Org.:: Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

Sponsoring Org.:: USDOE National Nuclear Security Administration (NNSA)

OSTI Identifier:: 1444079

Report Number(s):: SAND-2018-5832J
Journal ID: ISSN 2192-9262; 663667

Grant/Contract Number:: AC04-94AL85000

Resource Type:: Accepted Manuscript

Journal Name:: Metallography, Microstructure and Analysis

Additional Journal Information:: Journal Name: Metallography, Microstructure and Analysis; Journal ID: ISSN 2192-9262

Publisher:: Springer

Country of Publication:: United States

Language:: English

Subject:: 36 MATERIALS SCIENCE; aluminum alloys; additive manufacturing; fractography; mechanical behavior; microstructure

Citation Formats


                    Finfrock, Christopher B., Exil, Andrea, Carroll, Jay D., and Deibler, Lisa Anne. Effect of Hot Isostatic Pressing and Powder Feedstock on Porosity, Microstructure, and Mechanical Properties of Selective Laser Melted AlSi10Mg.  United States: N. p., 2018. 
        Web.  doi:10.1007/s13632-018-0456-z.

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                    Finfrock, Christopher B., Exil, Andrea, Carroll, Jay D., & Deibler, Lisa Anne. Effect of Hot Isostatic Pressing and Powder Feedstock on Porosity, Microstructure, and Mechanical Properties of Selective Laser Melted AlSi10Mg.  United States.  doi:10.1007/s13632-018-0456-z.

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                    Finfrock, Christopher B., Exil, Andrea, Carroll, Jay D., and Deibler, Lisa Anne. Wed .  
        "Effect of Hot Isostatic Pressing and Powder Feedstock on Porosity, Microstructure, and Mechanical Properties of Selective Laser Melted AlSi10Mg".  United States.  doi:10.1007/s13632-018-0456-z.  https://www.osti.gov/servlets/purl/1444079.

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@article{osti_1444079,

  title        = {Effect of Hot Isostatic Pressing and Powder Feedstock on Porosity, Microstructure, and Mechanical Properties of Selective Laser Melted AlSi10Mg},

  author       = {Finfrock, Christopher B. and Exil, Andrea and Carroll, Jay D. and Deibler, Lisa Anne},

  abstractNote = {AlSi10Mg tensile bars were additively manufactured using the powder-bed selective laser melting process. Samples were subjected to stress relief annealing and hot isostatic pressing. Tensile samples built using fresh, stored, and reused powder feedstock were characterized for microstructure, porosity, and mechanical properties. Fresh powder exhibited the best mechanical properties and lowest porosity while stored and reused powder exhibited inferior mechanical properties and higher porosity. The microstructure of stress relieved samples was fine and exhibited (001) texture in the z-build direction. Microstructure for hot isostatic pressed samples was coarsened with fainter (001) texture. To investigate surface and interior defects, scanning electron microscopy, optical fractography, and laser scanning microscopy techniques were employed. Hot isostatic pressing eliminated internal pores and reduced the size of surface porosity associated with the selective laser melting process. Hot isostatic pressing tended to increase ductility at the expense of decreasing strength. Furthermore, scatter in ductility of hot isostatic pressed parts suggests that the presence of unclosed surface porosity facilitated fracture with crack propagation inward from the surface of the part.},

  doi          = {10.1007/s13632-018-0456-z},

  journal      = {Metallography, Microstructure and Analysis},

  number       = ,

  volume       = ,

  place        = {United States},

  year         = {2018},

  month        = {6}

}

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DOI: 10.1007/s13632-018-0456-z

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