Influence of processing parameters on the fabrication of a Cu-Al-Ni-Mn shape-memory alloy by selective laser melting

The Cu-based shape-memory alloy 81.95Cu-11.85Al-3.2Ni-3Mn (wt.%) was processed by selective laser melting (SLM) and the parameters were optimised to obtain compact, fully martensitic samples with a high relative density of up to 99%. Next to the energy dissipated in the material, the scanning strategy was varied and an additional remelting step was applied. The influence of the different processing parameters on the overall density, the defect distribution as well as the grain sizes was then analysed. The processing technique has a strong influence on the degree of porosity and the distribution of the pores, the grain size as well as the grain morphology. SLM thus allows the targeted manipulation of microstructures during manufacturing. Simultaneously, this work stresses the importance of establishing the proper processing parameters for producing high-quality samples.