Surface texture measurement for additive manufacturing

By Andrew Triantaphyllou, C. Giusca, G. Macaulay, Felix Roerig, M. Hoebel, Richard Leach, Ben Tomita, K. Milne. 2015

223 citations recorded by the source corpus.

The surface texture of additively manufactured metallic surfaces made by powder bed methods is affected by a number of factors, including the powder’s particle size distribution, the effect of the heat source, the thickness of the printed layers, the angle of the surface relative to the horizontal build bed and the effect of any post processing/finishing. The aim of the research reported here is to understand the way these surfaces should be measured in order to characterise them. In published research to date, the surface texture is generally reported as an Ra value, measured across the lay. The appropriateness of this method for such surfaces is investigated here. A preliminary investigation was carried out on two additive manufacturing processes—selective laser melting (SLM) and electron beam melting (EBM)—focusing on the effect of build angle and post processing. The surfaces were measured using both tactile and optical methods and a range of profile and areal parameters were reported. Test coupons were manufactured at four angles relative to the horizontal plane of the powder bed using both SLM and EBM. The effect of lay—caused by the layered nature of the manufacturing process—was investigated, as was the required sample area for optical measurements. The surfaces were also measured before and after grit blasting.

Subfields: Automotive Engineering, Computational Mechanics, Mechanical Engineering

View Paper: https://www.semanticscholar.org/paper/a70026832af8d6e03fedbf652ff024106962355f

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Automotive Engineering

1. A. Fatemi
2. N. Sanaei
3. N. Phan
4. Nima Shamsaei
5. Jonathan W. Pegues
6. Mujian Xia
7. Swee Hock Yeo
8. A. Nagalingam

In Computational Mechanics

1. Nicola Senin
2. J. Milewski
3. Swee Hock Yeo
4. D. Warner
5. A. Nagalingam
6. Liam Blunt
7. Nima Shamsaei
8. P. Peyre

In Mechanical Engineering

1. A. Fatemi
2. N. Sanaei
3. N. Phan
4. Nima Shamsaei
5. Jonathan W. Pegues
6. D. Warner
7. P. Li
8. Mujian Xia

Citations in the corpus

• Process defects and in situ monitoring methods in metal powder bed fusion: a review (2017, unknown): “In particular, downward- and up-ward surfaces are known to have considerably different roughness properties (Triantaphyllou et al., 2015).”
• Influence of SLM process parameters on the surface finish, porosity rate and fatigue behavior of as-built Inconel 625 parts (2017, result): “(Leary, 2017) and (Triantaphyllou et al., 2015) observed the same behaviour in a Ti6Al4V.”
• Additive Manufacturing of Metals: From Fundamental Technology to Rocket Nozzles, Medical Implants, and Custom Jewelry (2017, methodology): “Objects made from fused powder have a surface finish of partially fused powder and display tracks of the layered melting, as shown for both SLM and EBM built parts (Triantaphyllou et al. 2015), in Fig.”
• Effect of Process Parameters on the Generated Surface Roughness of Down-Facing Surfaces in Selective Laser Melting (2019, background): “However, this in turn results in the increase of process steps, in particular, removal of the support could exhibit defects, such as burr formation, leading to even higher roughness [10].”
• A review on the state-of-the-art of surface finishing processes and related ISO/ASTM standards for metal additive manufactured components (2020, background): “(a) Build orientation of parts with respect to PBF build plate (Urlea and Brailovski 2017) and (b) components built at various orientations with and without support structures (Triantaphyllou et al. 2015).”
• Improving additive manufacturing processability of hard-to-process overhanging structure by selective laser melting (2017, result): “Triantaphyllou et al. (2015) investigated the upward and downward-facing surface roughness for varying angles, compared results from multiple measurement instruments, and found that the Ssk parameter can be used for differentiating between upward- and downward-facing surfaces.”
• High cycle fatigue behavior and life prediction for additively manufactured 17-4 PH stainless steel: Effect of sub-surface porosity and surface roughness (2020, unknown): “In fact, this usually happens when parts are fabricated inclined with respect to the building direction and without supporting structures (see Figure 1), as the unmelted powder on which the down-skin surfaces are fabricated cannot dissipate heat as the wrought material [21].”
• X-Ray Microcomputed Tomography in Additive Manufacturing: A Review of the Current Technology and Applications (2018, unknown): “AM parts require surface roughness assessment, but traditional tools such as tactile and optical profilometers and laser scanners work only on the exterior surfaces of parts, and often only in lines or on flat surfaces.(81,82) It was shown previously that individual line profiles in CT images can be”
• Surface texture metrology for metal additive manufacturing: a review (2016, methodology): “[26] found that Sa and Sq were suitable measurement parameters for SLM and EBM Ti6AL4V components and that Ssk (skewness) differentiated upskin from downskin surfaces.”
• Fatigue of additive manufactured Ti-6Al-4V, Part I: The effects of powder feedstock, manufacturing, and post-process conditions on the resulting microstructure and defects (2020, background): “8c. Melt pool on unsupported layers is also affected by gravity which makes them sag into the un-melted powder underneath and creates much rougher down–skin surfaces than up-skin surfaces [68].”