The 2017 Annual International Solid Freeform Fabrication (SFF) Symposium – An Additive Manufacturing (AM) Conference was held 7–9 August 2017 in Austin, Texas, USA. It was attended by 650 researchers who presented almost 470 technical presentations. Six papers in this issue represent outstanding papers from the conference and demonstrate the variety and richness of the field. The 2018 SFF Symposium is set for 13–15 August 2018 in Austin, Texas, USA. The abstract submission deadline is 15 April 2018. The conference website is http://sffsymposium.engr.utexas.edu/.
Like all indicators of AM, participation and interest in the SFF Symposium has grown phenomenally over the last 10 years. The SFF Symposium has skyrocketed in attendance. The conference attendance five years ago was only 170 participants. This growth is evident in both technical and non-technical AM meetings around the world. Patent applications, journal submissions, machine sales and materials sales all show similar increases.
The papers included in this special issue demonstrate the breath of the field. The importance of slicing methods is illustrated (Adams and Turner Citation2018). In situ imaging of AM builds in process is important for early identification of defects and potentially for in situ repair. Use of thermal imaging (Cheng et al. Citation2018) and optical emission spectroscopy (Dunbar and Nassar Citation2018) are applied to nickel-based alloy 718 to characterise the melt pool, porosity and fusion errors. Metrology is a long-term issue for AM parts, particularly metallic parts where residual stress during the build can affect part geometry. A new method facilitating the estimation of residual stress in metals is presented (Sillars et al. Citation2018). Surface integrity is also an important metrological feature. A hybrid AM/subtractive method is presented with results for nickel-based alloy 718 (Brown et al. Citation2018). Finally, materials extrusion AM is very widespread due primarily to the low-cost associated with many materials extrusion fabricators. However, the mechanical properties are generally quite inferior compared to other AM approaches and to conventional manufacturing such as injection moulding. Deployment of a multi-axis materials extrusion fabricator to create a surface reinforcing ‘skin’ is shown to improve the mechanical properties (Kubalak et al. Citation2018).
References
- Adams, D. and Turner, C., 2018. An implicit slicing method for additive manufacturing processes. Virtual and Physical Prototyping, 13 (1), 2–7.
- Brown, D., et al., 2018. Surface integrity of Inconel 718 by hybrid selective laser melting and milling. Virtual and Physical Prototyping, 13 (1), 26–31.
- Cheng, B., et al., 2018. Infrared thermal imaging for melt pool analysis in SLM: a feasibility investigation. Virtual and Physical Prototyping, 13 (1), 8–13.
- Dunbar, A. and Nassar, A., 2018. Assessment of optical emission analysis for in process monitoring of powder bed fusion additive manufacturing. Virtual and Physical Prototyping, 13 (1), 14–19.
- Kubalak, J., Wicks, A., and Williams, C., 2018. Using multi-axis material extrusion to improve mechanical properties through surface reinforcement. Virtual and Physical Prototyping, 13 (1), 32–38.
- Sillars, S., et al., 2018. The three-prong method: a novel assessment of residual stress in laser powder bed fusion. Virtual and Physical Prototyping, 13 (1), 20–25.