Original Article Proc IMechE Part B: J Engineering Manufacture 1–10 Ó IMechE 2020 Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/0954405420970088 journals.sagepub.com/home/pib Investigation of significant factors on deformation with powder bed fusion system Tan Pan 1 , Lan Li 1 , Xinchang Zhang 1 , Aaron Flood 1 , Sreekar Karnati 1 , Wenyuan Cui 1 , Yunlu Zhang 1 , Wei Li 2 and Frank Liou 1 Abstract Powder bed fusion (PBF) is one of the most popular techniques in additive manufacturing (AM). The PBF technique of selective laser melting (SLM) consolidates powder layer by layer using a laser as the energy source. This technique ensures the processes capability of fabricating components with internal and external complex geometries, which could be challenging to make with conventional manufacturing methods. However, the cyclic heating and cooling inherent in this process give rise to the buildup of residual stresses, which can distort orcompletely deform the part. In this work, a screening build with nine factors was designed to investigate the effects of component size, support structure, and energy input on the build completion and average distortion induced by the inherent residual stress. Experimental results indicated that support hatch spacing, part thickness, and support contact spacing played dominant roles in the final qual- ity (i.e. resultant deformation) of the built parts. The identified significant factors from this study can be carefully selected to increase the success rates of single builds and improve the qualities (i.e. geometric accuracy) of the final products. Keywords Selective laser melting, deformation, distortion, residual stress, support structures Date received: 20 February 2020; accepted: 11 October 2020 Introduction Additive manufacturing (AM) consolidates a compo- nent layer by layer with an energy source to selectively melt materials. The nature of this layer-wise manufac- turing process enables the fabrication of the compo- nents with complex geometries with less assembling or machining, which is quite challenging, or impossible, to achieve with conventional subtractive manufacturing methods. However, defects impede the broad adoption of AM, 1 such as the introductions of porosity, 2–6 dis- tortion, 7–9 and residual stress. 10–13 These defects could worsen the geometric accuracy, surface roughness, and mechanical property (e.g. fatigue life 14 ). One of the potential causes of the introduction of those defects could be improper sets of build process parameters. According to the porosity creation mechanism, four melting zones could be defined with varying laser pow- ers and scan speeds, 15,16 including a fully dense zone, over melting zone, incomplete melting zone, and over- heating zone. In most cases, the fully dense zone is most desired. At the same time, the optimal parameter combinations need to be tested out, and the final parts require to be characterized to demonstrate the applic- ability and performance. In most laser PBF system, process parameter is a combination of laser power, scan speed, hatch spacing, and layer thickness. Energy den- sity, 4,6,15,17 which is defined in equation (1), is widely accepted and can represent the combination of the effects of those parameters. E = P v  h  t ð1Þ 1 Department of Mechanical & Aerospace Engineering, Missouri University of Science and Technology, Rolla, Missouri, USA 2 Department of Mechanical Engineering, University of Texas at Dallas, Richardson, TX, USA Corresponding author: Tan Pan, Department of Mechanical & Aerospace Engineering, Missouri University of Science and Technology, 105W 16th St, Rolla, MO 65409, USA. Email: tpb44@mst.edu