Abstract
The effects of using recycled AlSi10Mg aluminium alloy powders on the mechanical properties and the corrosion-resistance behaviour of the components manufactured via selective laser melting (SLM) were analysed. The microstructural results show that the utilisation of recycled powder causes coarsening of interdendritic Si-network, especially along the melt pool boundaries of the SLM specimens. The corrosion resistance of the samples was evaluated by means of neutral salt spray (NSS) tests for 1000 h and mass loss measurements. The corrosion behaviour, in terms of surface roughness, density and porosity, however, remains almost the same between the samples produced by virgin and recycled powder. In addition to this, a passive NDE tool has been used to investigate and study the impact of powders on the corrosion performance of the alloy: Acoustic Emission (AE) technique. SEM observations allowed to highlight the morphological differences in the surface of the test specimens induced by the exposure condition. Thus, it was possible to correlate the AE results to corrosion mechanisms activated on the surfaces of the test specimen. A good correlation between the corrosion-resistance behaviour and the AE test results were obtained. Finally, the mechanical properties before and at the end of the accelerated corrosion were evaluated according to the yield strength, tensile strength, and elongation at breakage. The results showed comparable mechanical properties for the samples produced using both virgin and recycled powders. Besides, no notable influence of the exposure to corrosive environment on the mechanical performance was observed.
Highlights
Additive Manufacturing (AM) has revolutionised the way of conceiving, designing and producing high value components and has given rise to new opportunities and important market prospects
The use of components fabricated with Additive manufacturing (AM) technologies has increased in several industrial applications, including aerospace, automotive and marine industries, that require the use of metallic materials capable of withstanding severe thermal and mechanical stress, even in very hostile environments
neutral salt spray (NSS) tests were carried out according to the ASTM B117 standard [23], in which dog bone-shaped samples realised using virgin and recycled AlSi10Mg alloy powders were exposed to 5% NaCl solution in a salt spray cabinet, operated at 35 °C
Summary
Additive Manufacturing (AM) has revolutionised the way of conceiving, designing and producing high value components and has given rise to new opportunities and important market prospects. The use of components fabricated with AM technologies has increased in several industrial applications, including aerospace, automotive and marine industries, that require the use of metallic materials capable of withstanding severe thermal and mechanical stress, even in very hostile environments. Compared to the traditional manufacturing routes, SLM processes has inherent advantages owing to its fewer restrictions in shape (does not require a mould), short lead times and high resolution for complex shapes and structures. The overhead cost of operation is less for SLM in manufacturing complex shapes and structures with high resolution when compared to the traditional manufacturing techniques. As indicated by Yusuf et al [1], the extremely high cooling-rates during SLM process, on the order of 1 06–108 °C/s, can produce very fine-grained structure in the SLM parts, characterised by increased mechanical properties, including higher yield and tensile strengths, better corrosion resistance and enhanced fatigue life. It has some limitations such as the high price of the feedstock
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
