PAPERS: Process Planning Considerations for AM

Build Direction Effects on Microchannel Tolerance and Surface Roughness

[+] Author and Article Information
Jacob C. Snyder

Department of Mechanical
and Nuclear Engineering,
Penn State University,
3127 Research Drive,
State College, PA 16801
e-mail: jacob.snyder@psu.edu

Curtis K. Stimpson

Department of Mechanical
and Nuclear Engineering,
Penn State University,
3127 Research Drive,
State College, PA 16801
e-mail: curtis.stimpson@psu.edu

Karen A. Thole

Department of Mechanical
and Nuclear Engineering,
Penn State University,
136 Reber Building, University Park, PA 16802
e-mail: kthole@psu.edu

Dominic J. Mongillo

Pratt and Whitney,
400 Main Street,
East Hartford, CT 06118

Contributed by the Design for Manufacturing Committee of ASME for publication in the JOURNAL OF MECHANICAL DESIGN. Manuscript received March 4, 2015; final manuscript received July 7, 2015; published online October 12, 2015. Assoc. Editor: Christopher Williams.

J. Mech. Des 137(11), 111411 (Oct 12, 2015) (7 pages) Paper No: MD-15-1190; doi: 10.1115/1.4031071 History: Received March 04, 2015; Revised July 07, 2015

With the advance of additive manufacturing (AM) processes, complex designs can be created with engineering metals. One specific advantage of this greater design space is the ability to create small internal channels and passageways for cooling high heat flux or temperature applications such as electronics and gas turbine airfoils. These applications can have complex shapes, which when coupled with the required small channel sizes, make traditional finishing processes a challenge for additively manufactured parts. Therefore, it is desirable for designers to be able to use AM parts with small internal channels that are as-built. To achieve this goal, however, designers must know how the AM process affects internal channel tolerances and roughness levels, since both impact the amount of cooling that can be achieved in actual applications. In this study, the direct metal laser sintering (DMLS) process, more generically referred to as selective laser melting (SLM), was used to additively manufacture test coupons. The AM build direction was varied to study its effect on small microsized, circular channels. Specifically, X-ray computed tomography (CT-scan) was used to nondestructively inspect the interior of the test coupons. Using the data from the CT-scans, internal surface roughness, geometric tolerances, and deviations from the computer-aided design (CAD) model were calculated. In comparing the data, significant differences were seen between the three different build directions.

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Han, J. C., Dutta, S., and Ekkad, S., 2000, Gas Turbine Heat Transfer and Cooling, Taylor and Francis, New York.
Strano, G., Hao, L., Everson, R. M., and Evans, K. E., 2013, “Surface Roughness Analysis, Modelling and Prediction in Selective Laser Melting,” J. Mater. Process. Technol., 213(4), pp. 589–597. [CrossRef]
Ventola, L., Robotti, F., Dialameh, M., Calignano, F., Manfredi, D., Chiavazzo, E., and Asinari, P., 2014, “Rough Surfaces With Enhanced Heat Transfer for Electronics Cooling by Direct Metal Laser Sintering,” Int. J. Heat Mass Transf., 75, pp. 58–74. [CrossRef]
Simonelli, M., Tse, Y. Y., and Tuck, C., 2014, “Effect of the Build Orientation on the Mechanical Properties and Fracture Modes of SLM Ti–6Al–4V,” Mater. Sci. Eng. A, 616, pp. 1–11. [CrossRef]
Delgado, J., Ciurana, J., and Rodríguez, C. A., 2012, “Influence of Process Parameters on Part Quality and Mechanical Properties for DMLS and SLM With Iron-Based Materials,” Int. J. Adv. Manuf. Technol., 60(5–8), pp. 601–610. [CrossRef]
Cooper, D. E., Stanford, M., Kibble, K. A., and Gibbons, G. J., 2012, “Additive Manufacturing for Product Improvement at Red Bull Technology,” Mater. Des., 41, pp. 226–230. [CrossRef]
Song, Y.-A., and Koenig, W., 1997, “Experimental Study of the Basic Process Mechanism for Direct Selective Laser Sintering of Low-Melting Metallic Powder,” CIRP Ann.—Manuf. Technol., 46(1), pp. 127–130. [CrossRef]
Calignano, F., Manfredi, D., Ambrosio, E. P., Iuliano, L., and Fino, P., 2013, “Influence of Process Parameters on Surface Roughness of Aluminum Parts Produced by DMLS,” Int. J. Adv. Manuf. Technol., 67(9–12), pp. 2743–2751. [CrossRef]
Senthilkumaran, K., Pandey, P. M., and Rao, P. V. M., 2009, “Influence of Building Strategies on the Accuracy of Parts in Selective Laser Sintering,” Mater. Des., 30(8), pp. 2946–2954. [CrossRef]
Simchi, A., Petzoldt, F., and Pohl, H., 2003, “On the Development of Direct Metal Laser Sintering for Rapid Tooling,” J. Mater. Process. Technol., 141(3), pp. 319–328. [CrossRef]
Khaing, M. W., Fuh, J. Y. H., and Lu, L., 2001, “Direct Metal Laser Sintering for Rapid Tooling: Processing and Characterisation of EOS Part,” J. Mater. Process. Technol., 113(1–3), pp. 269–272. [CrossRef]
Masood, S. H., Rattanawong, W., and Iovenitti, P., 2003, “A Generic Algorithm for a Best Part Orientation System for Complex Parts in Rapid Prototyping,” J. Mater. Process. Technol., 139(1–3), pp. 110–116. [CrossRef]
Masood, S. H., and Rattanawong, W., 2002, “A Generic Part Orientation System Based on Volumetric Error in Rapid Prototyping,” Int. J. Adv. Manuf. Technol., 19(3), pp. 209–216.
Arni, R., and Gupta, S., 2001, “Manufacturability Analysis of Flatness Tolerances in Solid Freeform Fabrication,” ASME J. Mech. Des., 123(1), pp. 148–156. [CrossRef]
Paul, R., and Anand, S., 2011, “Optimal Part Orientation in Rapid Manufacturing Process for Achieving Geometric Tolerances,” J. Manuf. Syst., 30(4), pp. 214–222. [CrossRef]
Paul, R., and Anand, S., 2013, “Material Shrinkage Modeling and Form Error Prediction in Additive Manufacturing Processes,” NAMRI/SME, pp. 515–525.
Paul, R., Anand, S., and Gerner, F., 2014, “Effect of Thermal Deformation on Part Errors in Metal Powder Based Additive Manufacturing Processes,” ASME J. Manuf. Sci. Eng., 136(3), p. 031009. [CrossRef]
Ning, Y., Wong, Y. S., Fuh, J. Y. H., and Loh, H. T., 2006, “An Approach to Minimize Build Errors in Direct Metal Laser Sintering,” IEEE Trans. Autom. Sci. Eng., 3(1), pp. 73–80. [CrossRef]
Manfredi, D., Calignano, F., Krishnan, M., Canali, R., Ambrosio, E. P., and Atzeni, E., 2013, “From Powders to Dense Metal Parts: Characterization of a Commercial AlSiMg Alloy Processed Through Direct Metal Laser Sintering,” Materials, 6(3), pp. 856–869. [CrossRef]
Stimpson, C. K., Snyder, J. C., and Thole, K. A., 2015, “Roughness Effects on Flow and Heat Transfer for Additively Manufactured Channels,” ASME Paper No. GT2015-43940.
Snyder, J. C., Stimpson, C. K., and Thole, K. A., 2015, “Build Direction Effects on Additively Manufactured Channels,” ASME Paper No. GT2015-43935.
EOS GmbH, Basic Training EOSINT M 280.
Becker, B., Maier, D., and Reinhart, C., 2012, “Computer Tomography Has Arrived in Automated Inspection Processes, Combining Material and Geometry Analyses,” 18th World Conference on Non-Destructive Testing, Durban, South Africa, Apr. 16–20.
VG Studio MAX, Vers. 2.2, Volume Graphics GmbH, Heidelberg, Germany.
Zhu, H. H., Lu, L., and Fuh, J. Y. H., 2006, “Study on Shrinkage Behaviour of Direct Laser Sintering Metallic Powder,” Proc. Inst. Mech. Eng. Part B, 220(2), pp. 183–190. [CrossRef]
Raghunath, N., and Pandey, P. M., 2007, “Improving Accuracy Through Shrinkage Modelling by Using Taguchi Method in Selective Laser Sintering,” Int. J. Mach. Tools Manuf., 47(6), pp. 985–995. [CrossRef]
Louvis, E., Fox, P., and Sutcliffe, C. J., 2011, “Selective Laser Melting of Aluminium Components,” J. Mater. Process. Technol., 211(2), pp. 275–284. [CrossRef]
Verhaeghe, F., Craeghs, T., Heulens, J., and Pandelaers, L., 2009, “A Pragmatic Model for Selective Laser Melting With Evaporation,” Acta Mater., 57(20), pp. 6006–6012. [CrossRef]
Olakanmi, E. O., 2013, “Selective Laser Sintering/Melting (SLS/SLM) of Pure Al, Al–Mg, and Al–Si Powders: Effect of Processing Conditions and Powder Properties,” J. Mater. Process. Technol., 213(8), pp. 1387–1405. [CrossRef]
DeGarmo, P. E., Black, J. T., and Kohser, R. A., 2003, Materials and Processes in Manufacturing, Wiley, Hoboken, NJ.


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Fig. 2

Coupon orientation and support structures (shown in red/darker gray) for the (a) vertical, (b) horizontal, and (c) diagonal build directions

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Fig. 1

Designed dimensions, shape, and channel spacing of the test coupons

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Fig. 6

Distribution of the difference between the coupon surface points and the CAD model for the three different build directions

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Fig. 7

Three-dimensional surfaces representing the internal channel topology of a single channel for the (a) vertical, (b) horizontal, and (c) diagonal build directions

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Fig. 8

Axial slices at various streamwise locations of (a) vertically, (b) horizontally, and (c) diagonally built channels

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Fig. 3

Geometric tolerance definitions for (a) concentricity, (b) circularity, and (c) total runout

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Fig. 4

A slice taken along the channel axis showing the roughness features and surface fit for one plane of the vertically built channel surface

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Fig. 5

Comparison of surface roughness contours from (a) an optical profilometer and (b) a CT scanner showing features missing in CT scan data



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