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PurposeThe purpose of this paper is to compare different post processing techniques for improving the high surface roughness (SR) characteristic of parts generated by selected laser melting (SLM).Design/methodology/approachTest parts were built by SLM and their surface was characterized via SEM and optical measurements. The surface of the as‐generated parts was then modified by grinding, sand blasting and electrolytic and plasma polishing to reduce the SR.FindingsThe change of the SR after the different surface treatments was quantified and compared. The effectiveness and usability of the post processing techniques and their combinations were determined. The results indicate that some of the post processes are only usable for simple structures.Research limitations/implicationsThe amount of abrasion induced by the different surface treatments was not quantified. A major focus of future work should deal with this issue.Practical implicationsThe surface quality of parts with simple geometry can be enhanced by simple methods such as grinding. Complex parts need more advanced techniques, such as electrolytic polishing.Originality/valueThe effect of different post processing techniques for improving the surface roughness of SLM‐generated parts has been analyzed for the first time. This paper can help to improve the SR of parts produced by SLM.

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Ti-45Nb is one of the potential alloys that can be applied for biomedical applications as implants due to its low Young's modulus. Ti-45Nb (wt.%) gas atomized powders were used to produce bulk samples by selective laser melting with three different parameter sets (energy inputs). A β-phase microstructure consisting of elliptical grains with an enriched edge of titanium was observed by scanning electron microscopy and X-ray diffraction studies. The mechanical properties of these samples were evaluated using hardness and compression tests, which suggested that the strength of the samples increases with increasing energy input within the range considered.

The interest for a wider range of useable materials for the technology of selective laser melting is growing. In this work we describe a new way to optimize the process parameters for selective laser melting of a beta solidifying titanium aluminide. This kind of material has so far not been processed successfully by this method. The new approach is easy to conduct and well transferable to other materials. It is based on the fact that the parts generated from selective laser melting can be described by an addition of multiple single tracks. Multiple types of single track experiments are performed and in combination with knowledge from laser welding tests optimized parameter combinations are derived. Compact samples are built with the optimized process parameters and characterized in terms of microstructure, phase composition and mechanical properties. With this technique the generation of a TNM-B1 titanium aluminide alloy sample with a density greater than 99% could be achieved. The mechanical properties are comparable with material produced by conventional techniques.

Al-12Si (80 vol%)-Ti 52.4 Al 42.2 Nb 4.4 Mo 0.9 B 0.06 (at.%) (TNM) composites were successfully produced by the selective laser melting (SLM). Detailed structural and microstructural analysis shows the formation of the Al 6 MoTi intermetallic phase due to the reaction of the TNM reinforcement with the Al-12Si matrix during SLM. Compression tests reveal that the composites exhibit significantly improved properties (;140 and ;160 MPa higher yield and ultimate compressive strengths, respectively) compared with the Al-12Si matrix. However, the samples break at ;6% total strain under compression, thus showing a reduced plasticity of the composites. Sliding wear tests were carried out for both the Al-12Si matrix and the Al-12Si-TNM composites. The composites perform better under sliding wear conditions and the wear rate increases with increasing loads. At high loads, the wear takes place at three different rates and the wear rate decreases with increasing experiment duration.